Hopefully, that got your attention! Please watch the following video.
The video is about teaching youngsters to develop the critical thinking skills necessary to make healthy food choices.
The secret to successful weight loss & maintenance:-
Formulate a good plan. A good plan is one that works and is sustainable. Exercise mainly increases fitness, but also increases energy expenditure. See Calories Burned - Walking: 3.5 mph (17 minutes per mile). E.g. a 250lb man who walks for 45 minutes expends 378kcals.
The vast majority of people who visit "fast food" establishments don't have the critical thinking skills necessary to make healthy food choices. "Fast food" establishments use every marketing trick in the book to influence people to make unhealthy food choices and consume as much of them as possible.
As people are reluctant to go back for second helpings (as they think it makes them look greedy), super-sizing was invented, which allows people to eat considerably more food for not much extra money.
Delicious aromas increase hedonic hunger. Added sugar, salt and flavour enhancers make foods moreish.
Bright colours, cartoon characters and toys attract children.
Edward Bernays-style (emotion-targeted) marketing encourages people to visit "Fast food" establishments, make unhealthy food choices and over-consume them. See https://www.dailymotion.com/video/x2d29tf for more information. The first two minutes summarise.
Showing posts with label Energy. Show all posts
Showing posts with label Energy. Show all posts
Tuesday, 20 October 2015
Tuesday, 22 September 2015
How we lose weight: Oxidation of carbohydrate & fat in the body.
1. Oxidation of Carbohydrate in the body.
Glucose is C6H12O6, or 6(CH2O)6(CH2O)+ 6(O2) → 6(CO2) + 6(H2O) + energy
Oxygen is inhaled. Carbon Dioxide is exhaled. Water is lost in breath, wee, poo, sweat & other bodily fluids.
As 6 molecules of Oxygen produce 6 molecules of Carbon Dioxide, the Respiratory Exchange Ratio (RER) is 6/6 = 1
Converting molecular weights into their gram equivalents, 180g of Glucose combines with 192g of Oxygen to produce 264g of Carbon Dioxide plus 108g of water plus ~3,012kJ of energy. I'm using kJ rather than kcal, as the human body expends energy as mechanical energy (force x distance) and heat energy.
2. Oxidation of Fat in the body.
Fat is three fatty acids (Stearic Acid, say) attached to a Glycerol backbone. As ~95% of the energy released from a fat is from the three fatty acids, I'm ignoring the Glycerol backbone, to keep the maths as easy as possible. Stearic Acid is CH3(CH2)16COOH. I'm approximating it to 18(CH2), to keep the maths as easy as possible.54(CH2) + 81(O2) → 54(CO2) + 54(H2O) + energy
Oxygen is inhaled. Carbon Dioxide is exhaled. Water is lost in breath, wee, poo, sweat & other bodily fluids.
As 81 molecules of Oxygen produce 54 molecules of Carbon Dioxide, the RER is 54/81 = 0.67
Note: The RER for fats is actually 0.7, as the Glycerol backbone is converted into Glucose by the liver. As the RER for Glucose is 1, this raises the RER of my approximated fat by ~5%.
Converting molecular weights into their gram equivalents, 756g of approximated fat combines with 2,592g of Oxygen to produce 2,376g of Carbon Dioxide plus 972g of water plus ~28,468kJ of energy.
We lose weight by breathing, weeing, pooing, sweating etc. See also Majority of weight loss occurs 'via breathing'.
This doesn't invalidate Energy Balance, as the kcal/kJ values for foods merely represents the amount of chemical energy that can be released by oxidation of the various fuels in the foods. See Why Calories count (where weight change is concerned).
We gain weight by consuming fuels & water.
Monday, 18 August 2014
Dry carbohydrates, wet carbohydrates & energy density.
Karen N Davids thought of it first!
Here's a list of commonly-eaten carbohydrates and their Energy Density, in kcals/100g. From https://nutritiondata.self.com/
Dry Carbohydrates:-
Bread, White_________________________________________________266
Bread, Multi-grain___________________________________________265
Bread, Rye___________________________________________________258
Bread, Pumpernickel__________________________________________250
Bread, Whole-wheat___________________________________________247
Bread, reduced-calorie, white________________________________207
Bread, reduced-calorie, wheat________________________________198
Wet Carbohydrates:-
Pasta, fresh-refrigerated, plain, cooked_____________________131
Rice, white, long-grain, regular, cooked_____________________130
Rice, brown, long-grain, cooked______________________________111
Peas, green, frozen, cooked, boiled, drained, with salt_______78
Beans, kidney, red, mature seeds, cooked, boiled, with salt__127
Lentils, mature seeds, cooked, boiled, with salt_____________114
Vegetables, mixed, frozen, cooked, boiled, drained, with salt_60
Broccoli, frozen, spears, cooked, boiled, drained, with salt__28
Sweet potato, cooked, baked in skin, with salt________________92
Potatoes, boiled, cooked in skin, flesh, with salt____________87
Grapes, red or green (European type), raw_____________________69
Cherries, sweet, raw__________________________________________63
Pears, raw [Includes USDA commodity food A435]________________58
Apples, raw, with skin________________________________________52
If a diet is high in carbohydrates:-
Which of the above foods are most likely to result in weight gain?
Which of the above foods are most likely to result in weight loss?
Answers on a postcard, please!
 |
| From https://www.amazon.co.uk/Carbs-Weight-Manage-Nutritional-Carbohydrates-ebook/dp/B00DJF2GKU |
Here's a list of commonly-eaten carbohydrates and their Energy Density, in kcals/100g. From https://nutritiondata.self.com/
Dry Carbohydrates:-
Bread, White_________________________________________________266
Bread, Multi-grain___________________________________________265
Bread, Rye___________________________________________________258
Bread, Pumpernickel__________________________________________250
Bread, Whole-wheat___________________________________________247
Bread, reduced-calorie, white________________________________207
Bread, reduced-calorie, wheat________________________________198
Wet Carbohydrates:-
Pasta, fresh-refrigerated, plain, cooked_____________________131
Rice, white, long-grain, regular, cooked_____________________130
Rice, brown, long-grain, cooked______________________________111
Peas, green, frozen, cooked, boiled, drained, with salt_______78
Beans, kidney, red, mature seeds, cooked, boiled, with salt__127
Lentils, mature seeds, cooked, boiled, with salt_____________114
Vegetables, mixed, frozen, cooked, boiled, drained, with salt_60
Broccoli, frozen, spears, cooked, boiled, drained, with salt__28
Sweet potato, cooked, baked in skin, with salt________________92
Potatoes, boiled, cooked in skin, flesh, with salt____________87
Grapes, red or green (European type), raw_____________________69
Cherries, sweet, raw__________________________________________63
Pears, raw [Includes USDA commodity food A435]________________58
Apples, raw, with skin________________________________________52
If a diet is high in carbohydrates:-
Which of the above foods are most likely to result in weight gain?
Which of the above foods are most likely to result in weight loss?
Answers on a postcard, please!
Saturday, 26 July 2014
Some thoughts on the essentiality of dietary carbohydrates.
I didn't know that there's a watch strap called Essentiality. I do, now.
This is a book-marking post for thoughts I had in https://www.facebook.com/TheFatEmperor/posts/1442430506020812.
"The human body does not need carbohydrates from an external food source, because it is capable of very precisely and correctly assembling its own amounts of glucose that is needed in very small amounts for auxiliary and specialized functions." - Igor Butorski.
1) It's not precise. See How eating sugar & starch can lower your insulin needs.
2) It's not enough to fuel sustained medium-intensity exercise for everybody EDIT: if there's insufficient protein intake. See "Funny turns": What they aren't and what they might be and Everyone is Different.
From Blood Sugar is Stable:-
After liver glycogen has been depleted in starvation or on Nutritional Ketosis (Ketogenic Diets with less than 14% of total energy from Protein), total glucose production from liver & kidneys is ~100g/day.
From It's all in a day's work (as measured in Joules), the body oxidises carbohydrate at a rate exceeding ~4g/hour at exercise intensities exceeding ~25%, on a LCHF diet. This is unsustainable.
EDIT: If protein is consumed, total glucose production increases, up to a maximum of ~400g/day.
3) It's wasteful. Glucose production from protein converts ~50% of the most expensive macronutrient (protein) into the cheapest macronutrient (carbohydrate). It creates expensive urine, as the nitrogen part of amino acids is detoxified by being converted into urea by the liver and then wee'ed out by the kidneys.
4) Using the above argument, the human body does not need saturated fats & monounsaturated fats from an external food source, because it is capable of very precisely and correctly assembling its own amounts of saturated fats & monounsaturated fats (out of carbohydrate) that are needed in very small amounts for auxiliary and specialized functions.
If we consume only Essential Fatty Acids, Essential Amino Acids, Vitamins, Minerals, Fibre/Fiber, Water & Anutrients, there won't be much to eat. Also, there won't be a source of chemical energy to generate heat energy & mechanical energy. That's what dietary carbohydrates & fats are for!
Respiratory Exchange Ratio/Respiratory Quotient (RER/RQ) varies with carbohydrate & fat intake, as the body preferentially oxidises the fuel that's most readily available, when it's working properly. If it's not working properly, due to Insulin Resistance (IR), fix the IR rather than kludge the diet (by eating LCHF) to compensate for it. See Insulin Resistance: Solutions to problems for how to do this.
RER/RQ varies with Exercise Intensity.
Low-intensity exercise results in mostly fats being oxidised.
High-intensity exercise results in mostly carbohydrates being oxidised.
Medium-intensity exercise results in a mixture of fats & carbohydrates being oxidised.
 |
| From http://svpply.com/item/3229602/Swatch_Skin_Collection_Silver_Essentiality |
This is a book-marking post for thoughts I had in https://www.facebook.com/TheFatEmperor/posts/1442430506020812.
"The human body does not need carbohydrates from an external food source, because it is capable of very precisely and correctly assembling its own amounts of glucose that is needed in very small amounts for auxiliary and specialized functions." - Igor Butorski.
1) It's not precise. See How eating sugar & starch can lower your insulin needs.
2) It's not enough to fuel sustained medium-intensity exercise for everybody EDIT: if there's insufficient protein intake. See "Funny turns": What they aren't and what they might be and Everyone is Different.
From Blood Sugar is Stable:-
After liver glycogen has been depleted in starvation or on Nutritional Ketosis (Ketogenic Diets with less than 14% of total energy from Protein), total glucose production from liver & kidneys is ~100g/day.
From It's all in a day's work (as measured in Joules), the body oxidises carbohydrate at a rate exceeding ~4g/hour at exercise intensities exceeding ~25%, on a LCHF diet. This is unsustainable.
EDIT: If protein is consumed, total glucose production increases, up to a maximum of ~400g/day.
3) It's wasteful. Glucose production from protein converts ~50% of the most expensive macronutrient (protein) into the cheapest macronutrient (carbohydrate). It creates expensive urine, as the nitrogen part of amino acids is detoxified by being converted into urea by the liver and then wee'ed out by the kidneys.
4) Using the above argument, the human body does not need saturated fats & monounsaturated fats from an external food source, because it is capable of very precisely and correctly assembling its own amounts of saturated fats & monounsaturated fats (out of carbohydrate) that are needed in very small amounts for auxiliary and specialized functions.
If we consume only Essential Fatty Acids, Essential Amino Acids, Vitamins, Minerals, Fibre/Fiber, Water & Anutrients, there won't be much to eat. Also, there won't be a source of chemical energy to generate heat energy & mechanical energy. That's what dietary carbohydrates & fats are for!
Respiratory Exchange Ratio/Respiratory Quotient (RER/RQ) varies with carbohydrate & fat intake, as the body preferentially oxidises the fuel that's most readily available, when it's working properly. If it's not working properly, due to Insulin Resistance (IR), fix the IR rather than kludge the diet (by eating LCHF) to compensate for it. See Insulin Resistance: Solutions to problems for how to do this.
RER/RQ varies with Exercise Intensity.
Low-intensity exercise results in mostly fats being oxidised.
High-intensity exercise results in mostly carbohydrates being oxidised.
Medium-intensity exercise results in a mixture of fats & carbohydrates being oxidised.
Monday, 7 July 2014
Why Calories count (where weight change is concerned).
I have to add the words "where weight change is concerned", as nobody who knows what they're talking about claims that calories have anything to do with body composition or health (unless a prolonged imbalance makes somebody very underweight or very overweight).
Arguments used by Calorie Denialists include:-
1) Calories don't count because the human body isn't a Bomb Calorimeter and treats different macronutrients differently.
100g of liquid paraffin burns in a Bomb Calorimeter, yielding 900kcals. In a human, it passes through completely undigested. Ah-ha!, I hear you saying. This proves that the Energy Balance Equation is invalid. Uh, nope!
Calories in = Calories entering mouth - Calories exiting anus
As 100% of liquid paraffin calories entering the mouth exit the anus, Calories in = 0
This is why Sam Feltham's "Smash the Fat" "experiment" is utter nonsense. A high percentage of the large amount of raw almonds he ate would have exited his anus incompletely chewed, undigested & unabsorbed.
See the picture above? In the late 1800's, W.O. Atwater established Atwater Factors (3.75kcals/g for digestible Carbohydrates, 4kcals/g for Proteins, 5kcals/g for Ketones, 7kcals/g for Alcohols & 9kcals/g for Fats*) using Human Calorimeters, not Bomb Calorimeters.
∴ Atwater Factors are accurate.
*Fats containing different fatty acids have slightly different kcals/g. Fats containing long-chain fatty acids are 9kcals/g. Fats containing medium-chain fatty acids e.g. coconut oil are ~8kcals/g.
For more information, see Atwater
2) Calories don't count because Dietary Efficiency varies for different macronutrients.
Uh, nope! The Heat Power generated by the body is regulated by a NFB loop involving the Hypothalamus, Pituitary, Thyroid Axis, also Uncoupling Proteins (UCP's), also shivering, so as to maintain a body temperature of 37°C ±3°C. If this wasn't the case, different amounts & types of foods (also, changes in ambient temperature & clothing) would cause large variations in body temperature resulting in death, as the enzymes in our bodies function correctly over a limited range of temperatures.
Heat Power generated by the body (W) = Temperature difference between the body & ambient (°C) divided by Thermal resistance between the body & ambient (°C/W)
∴ Dietary Efficiency is irrelevant.
 |
| From https://docs.google.com/file/d/0Bz4TDaehOqMKSXZHUUVxWnl5VTQ/edit?usp=sharing |
Arguments used by Calorie Denialists include:-
1) Calories don't count because the human body isn't a Bomb Calorimeter and treats different macronutrients differently.
100g of liquid paraffin burns in a Bomb Calorimeter, yielding 900kcals. In a human, it passes through completely undigested. Ah-ha!, I hear you saying. This proves that the Energy Balance Equation is invalid. Uh, nope!
Calories in = Calories entering mouth - Calories exiting anus
As 100% of liquid paraffin calories entering the mouth exit the anus, Calories in = 0
This is why Sam Feltham's "Smash the Fat" "experiment" is utter nonsense. A high percentage of the large amount of raw almonds he ate would have exited his anus incompletely chewed, undigested & unabsorbed.
See the picture above? In the late 1800's, W.O. Atwater established Atwater Factors (3.75kcals/g for digestible Carbohydrates, 4kcals/g for Proteins, 5kcals/g for Ketones, 7kcals/g for Alcohols & 9kcals/g for Fats*) using Human Calorimeters, not Bomb Calorimeters.
∴ Atwater Factors are accurate.
*Fats containing different fatty acids have slightly different kcals/g. Fats containing long-chain fatty acids are 9kcals/g. Fats containing medium-chain fatty acids e.g. coconut oil are ~8kcals/g.
For more information, see Atwater
2) Calories don't count because Dietary Efficiency varies for different macronutrients.
Uh, nope! The Heat Power generated by the body is regulated by a NFB loop involving the Hypothalamus, Pituitary, Thyroid Axis, also Uncoupling Proteins (UCP's), also shivering, so as to maintain a body temperature of 37°C ±3°C. If this wasn't the case, different amounts & types of foods (also, changes in ambient temperature & clothing) would cause large variations in body temperature resulting in death, as the enzymes in our bodies function correctly over a limited range of temperatures.
Heat Power generated by the body (W) = Temperature difference between the body & ambient (°C) divided by Thermal resistance between the body & ambient (°C/W)
∴ Dietary Efficiency is irrelevant.
Saturday, 7 June 2014
Bray et al shows that a calorie *is* a calorie (where weight change is concerned).
Continued from Everyone is Different, Part 3.
EDIT: I made an error in stating that all of the extra calories came from fat, in the fat overfeeding phase. Thanks to commenter CynicalEng for pointing that out. It doesn't change the conclusion at all.
At 01:17 on 6th June, during a Facebook discussion, Fred Hahn told me:-
"Nigel Kinbrum - read this please.
Bray, et al. Shows that a Calorie is Not a Calorie and that Dietary Carbohydrate Controls Fat Storage.
Perhaps you'll learn something from a real expert who teaches metabolism to medical students at the largest medical school in the country."
So I did.
At 02:22, I replied:-
"Thanks for that. I read Feinman's blog post about Bray et al https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3777747/ some time ago.
There's a fundamental error in Feinman's analysis. As LeonRover pointed out in his comment https://feinmantheother.com/.../bray-et-al-shows-that.../...
In Diets:- "Absolute carbohydrate intake was kept constant throughout the study."
Also, in COMMENT:- "The extra calories in our study were fed as fat, as in several other studies, and were stored as fat..."
Oh, whoops! That may be why it was rejected by the editor."
Here's Figure 6 from Bray's study.
Some Definitions:-
LBM = Lean Body Mass
FM = Fat Mass = Body Fat
Weight change = (LBM change + FM change)
Weight change varies from ~+3.5kg (@ +2,500kJ/d) to ~+9.1kg (@ +5,900kJ/d).
(Maximum weight increase)/(minimum weight increase) = 2.6
(Maximum kJ/day increase)/(minimum kJ/day increase) = 2.36
∴ A calorie *is* a calorie (where weight change is concerned) ± some inter-personal variation.
∴ Insufficient protein can result in LBM loss (this is bad).
As LBM has a lower Energy Density (~600kcals/lb) than FM (~3,500kcals/lb), LBM loss can increase weight loss, when in a Caloric Deficit.
See The Energy Balance Equation, for a simple explanation, and The Dynamics of Human Body Weight Change, for an incredibly complicated one!
I was rather chuffed when Alan Aragon left the following comment at 04:34:-
"Nigel is correct. From Bray et al's text:
"The extra calories in our study were fed as fat, as in several other studies [33,34], and stored as fat with the lower percentage of excess calories appearing as fat in the high (25%) protein diet group. The higher fat intake in the low protein group probably reduced nutrient absorption (metabolizable energy) relative to the other groups and this would have brought the intake and expenditure closer together in this group.""
Feinman has deleted his blog post. However, his post I Told George Bray How to do it Right is still there. I believe that Dr. George A. Bray M.D. sort-of did it right.
Dr. George A. Bray used a "weight maintenance formula" in all three groups for the weight maintenance phase. He then changed the formula in all three groups to low-P, med-P and high-P formulas, for the fat overfeeding phase. Carbohydrate grams remained constant in all three groups for all phases, but additional fat grams were fewer in the high-P group than in the low-P group, for the fat overfeeding phase.
I would have used the low-P, med-P and high-P formulas for the weight maintenance phase and for the fat overfeeding phase, to equalise the additional fat grams in all three groups.
Continued on Everyone is different Part 4, Fallacies and another rant!
EDIT: I made an error in stating that all of the extra calories came from fat, in the fat overfeeding phase. Thanks to commenter CynicalEng for pointing that out. It doesn't change the conclusion at all.
At 01:17 on 6th June, during a Facebook discussion, Fred Hahn told me:-
"Nigel Kinbrum - read this please.
Bray, et al. Shows that a Calorie is Not a Calorie and that Dietary Carbohydrate Controls Fat Storage.
Perhaps you'll learn something from a real expert who teaches metabolism to medical students at the largest medical school in the country."
So I did.
At 02:22, I replied:-
"Thanks for that. I read Feinman's blog post about Bray et al https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3777747/ some time ago.
There's a fundamental error in Feinman's analysis. As LeonRover pointed out in his comment https://feinmantheother.com/.../bray-et-al-shows-that.../...
In Diets:- "Absolute carbohydrate intake was kept constant throughout the study."
Also, in COMMENT:- "The extra calories in our study were fed as fat, as in several other studies, and were stored as fat..."
Oh, whoops! That may be why it was rejected by the editor."
Here's Figure 6 from Bray's study.
Some Definitions:-
LBM = Lean Body Mass
FM = Fat Mass = Body Fat
Weight change = (LBM change + FM change)
Weight change varies from ~+3.5kg (@ +2,500kJ/d) to ~+9.1kg (@ +5,900kJ/d).
(Maximum weight increase)/(minimum weight increase) = 2.6
(Maximum kJ/day increase)/(minimum kJ/day increase) = 2.36
∴ A calorie *is* a calorie (where weight change is concerned) ± some inter-personal variation.
∴ Insufficient protein can result in LBM loss (this is bad).
As LBM has a lower Energy Density (~600kcals/lb) than FM (~3,500kcals/lb), LBM loss can increase weight loss, when in a Caloric Deficit.
See The Energy Balance Equation, for a simple explanation, and The Dynamics of Human Body Weight Change, for an incredibly complicated one!
I was rather chuffed when Alan Aragon left the following comment at 04:34:-
"Nigel is correct. From Bray et al's text:
"The extra calories in our study were fed as fat, as in several other studies [33,34], and stored as fat with the lower percentage of excess calories appearing as fat in the high (25%) protein diet group. The higher fat intake in the low protein group probably reduced nutrient absorption (metabolizable energy) relative to the other groups and this would have brought the intake and expenditure closer together in this group.""
Feinman has deleted his blog post. However, his post I Told George Bray How to do it Right is still there. I believe that Dr. George A. Bray M.D. sort-of did it right.
Dr. George A. Bray used a "weight maintenance formula" in all three groups for the weight maintenance phase. He then changed the formula in all three groups to low-P, med-P and high-P formulas, for the fat overfeeding phase. Carbohydrate grams remained constant in all three groups for all phases, but additional fat grams were fewer in the high-P group than in the low-P group, for the fat overfeeding phase.
I would have used the low-P, med-P and high-P formulas for the weight maintenance phase and for the fat overfeeding phase, to equalise the additional fat grams in all three groups.
Continued on Everyone is different Part 4, Fallacies and another rant!
Wednesday, 31 July 2013
Completing the trine: vive la différence!
First, the obligatory picture of Hannah Spearritt :-)
Women have a harder time losing weight than men. Women retain water more than men for hormonal reasons, but a factor that's overlooked is that, on average, healthy women have higher body-fat percentages than healthy men. This is because women have babies and men don't. Who knew? On the plus side, women produce more DHA than men.
Why should having higher body-fat percentages make a difference to weight loss? See What is the required energy deficit per unit weight loss? The energy deficit required to lose 1lb of body-weight increases with increasing body-fat percentage. It's rarely 3,500kcals per lb.
If you really love mathematics, see The Dynamics of Human Body Weight Change by Carson C. Chow and Kevin D. Hall.
From the above paper:- ΔU = ΔQ - ΔW
where ΔU is the change in stored energy in the body, ΔQ is a change in energy input or intake, and ΔW is a change in energy output or expenditure. This is the Energy Balance Equation. As I said back in Back to black, CIAB, pharmaceutical drug deficiencies & nerds.
Where body weight is concerned, calories count (but don't bother trying to count them).
Where body composition is concerned, partitioning counts.
Where health is concerned, macronutrient ratios, EFAs, minerals, vitamins & lifestyles count.
N.B. Poor health can adversely affect body weight and/or body composition, by increasing appetite and/or by adversely affecting partitioning.
Why should having higher body-fat percentages make a difference to weight loss? See What is the required energy deficit per unit weight loss? The energy deficit required to lose 1lb of body-weight increases with increasing body-fat percentage. It's rarely 3,500kcals per lb.
If you really love mathematics, see The Dynamics of Human Body Weight Change by Carson C. Chow and Kevin D. Hall.
From the above paper:- ΔU = ΔQ - ΔW
where ΔU is the change in stored energy in the body, ΔQ is a change in energy input or intake, and ΔW is a change in energy output or expenditure. This is the Energy Balance Equation. As I said back in Back to black, CIAB, pharmaceutical drug deficiencies & nerds.
Where body weight is concerned, calories count (but don't bother trying to count them).
Where body composition is concerned, partitioning counts.
Where health is concerned, macronutrient ratios, EFAs, minerals, vitamins & lifestyles count.
N.B. Poor health can adversely affect body weight and/or body composition, by increasing appetite and/or by adversely affecting partitioning.
Thursday, 28 March 2013
Use and abuse of technology and energy.
Take a look at the picture below.
Using technology and energy: Oil, ores, minerals and sand are turned into plastics, metals, ceramics and glasses. The latter cost and are worth more than the former. Using more technology and energy: Plastics, metals, ceramics and glasses are turned into smart-phones, computers, TV sets, cars, planes, musical instruments, w.h.y. The latter cost and are worth more than the former. Creating gizmos creates wealth and increases value.
Take a look at the picture below (hat-tip to Beth Mazur).
Using technology and energy: Produce are turned into crap-in-a-bag/box/bottle (CIAB). The latter cost more than the former but are worth less, as nutritional value has been reduced. Creating CIAB creates wealth but decreases value.
I would like there to be more production of gizmos and less production of CIAB.
 |
| Samsung Galaxy S vs iPhone 4 |
Take a look at the picture below (hat-tip to Beth Mazur).
 |
| You know who is really leaning in? Little Debbie. We have enough crap to eat. Dial it back a little. |
Using technology and energy: Produce are turned into crap-in-a-bag/box/bottle (CIAB). The latter cost more than the former but are worth less, as nutritional value has been reduced. Creating CIAB creates wealth but decreases value.
I would like there to be more production of gizmos and less production of CIAB.
Saturday, 16 March 2013
Everyone is Different, Part 2.
Cont'd from We are not all the same.
A long, long time ago...
I learned that Everyone is Different, thanks to a study by Julia H. Goedecke, Alan St Clair Gibson, Liesl Grobler, Malcolm Collins, Timothy D. Noakes and Estelle V. Lambert.
Well, stone the flamin' crows! Timothy D. Noakes' name just popped up in Alan Aragon's article 2013 NSCA Personal Trainers Conference: Looking Back at my Debate with Dr. Jeff Volek. Dr. Noakes has had problems with his blood glucose level and has adopted a very-low-carb/ketogenic diet.
What also caught my eye in Alan Aragon's article was (Note: TTE = Time To Exhaustion):-
"However, the authors’ conclusion is misleading since 2 of the 5 subjects experienced substantial drops in endurance capacity (48 and 51-minute declines in TTE, to be exact). One of the subjects had a freakishly high 84-minute increase in TTE, while the other increases were 3 and 30 minutes."
I expect that the subjects with 84 and 30 minute increases in TTE would be praising ketogenic diets, whereas the subjects with 48 and 51 minute declines in TTE would be cursing them and the subject with 3 minutes increase would be "Meh". Vive la difference!
Also note that sprint capability...remained constrained during the period of carbohydrate restriction. As mentioned in It's all in a day's work (as measured in Joules), exercise above a certain intensity (~85%VO2max) burns significant amounts of carbs, no matter how fat-adapted someone is.
Cont'd on Everyone is Different, Part 3.
A long, long time ago...
I learned that Everyone is Different, thanks to a study by Julia H. Goedecke, Alan St Clair Gibson, Liesl Grobler, Malcolm Collins, Timothy D. Noakes and Estelle V. Lambert.
Well, stone the flamin' crows! Timothy D. Noakes' name just popped up in Alan Aragon's article 2013 NSCA Personal Trainers Conference: Looking Back at my Debate with Dr. Jeff Volek. Dr. Noakes has had problems with his blood glucose level and has adopted a very-low-carb/ketogenic diet.
What also caught my eye in Alan Aragon's article was (Note: TTE = Time To Exhaustion):-
"However, the authors’ conclusion is misleading since 2 of the 5 subjects experienced substantial drops in endurance capacity (48 and 51-minute declines in TTE, to be exact). One of the subjects had a freakishly high 84-minute increase in TTE, while the other increases were 3 and 30 minutes."
I expect that the subjects with 84 and 30 minute increases in TTE would be praising ketogenic diets, whereas the subjects with 48 and 51 minute declines in TTE would be cursing them and the subject with 3 minutes increase would be "Meh". Vive la difference!
Also note that sprint capability...remained constrained during the period of carbohydrate restriction. As mentioned in It's all in a day's work (as measured in Joules), exercise above a certain intensity (~85%VO2max) burns significant amounts of carbs, no matter how fat-adapted someone is.
Cont'd on Everyone is Different, Part 3.
Monday, 7 January 2013
It’s the Calories, Stupid.
I thought I'd mark my return to blogging by taking the piss out of a certain Diet Doctor for his post It’s the Insulin, Stupid, who takes (and tweaks) Fig 7A from Hyperinsulinemia Drives Diet-Induced Obesity Independently of Brain Insulin Production.
At first glance, Fig 7A looks like a CIH believer's dream come true (apart from the words "High Fat Diet").
Hyperinsulinemia → Obesity.
Obesity is caused by too much insulin. Game, Set and Match to insulin.
Not so fast! Let's take a look at the rest of Fig 7.
Figure 7. Revisiting the Current Model of Obesity and Type 2 Diabetes(A)
The most widely accepted model of the pathogenesis of obesity and type 2
diabetes posits that a high-fat diet leads to obesity and insulin
resistance (there is debate about the relative order and causality of
these). In this widely held view, insulin resistance then leads to
hyperinsulinemia, which is followed by β cell exhaustion, and then type 2
diabetes. The accepted model is incompatible with our results that put
the insulin hypersecretion genetically upstream of obesity.(B)
Our data support a model whereby insulin levels must be kept low to
maintain energy expenditure in white adipose tissue via the expression
of Ucp1. Our data do not address the order of subsequent events
after obesity (outside the yellow box), such as insulin resistance
and/or type 2 diabetes, since they were not observed in our studies. In
other words, the effects of insulin gene dosage on obesity are
independent of sustained changes in glucose homeostasis or insulin
resistance.
↑ Peripheral Hyperinsulinemia → ↓ Uncoupling Proteins (WAT) → ↓ Energy Expenditure → ↑ Obesity.
Obesity is caused by a reduction in energy expenditure in these mice. Game, Set and Match to The Energy Balance Equation. It’s the Calories, Stupid. In these mice, energy expenditure is strongly influenced by insulin levels. In humans, not a lot. In humans, insulin can act as a stimulant or a sedative.
I'm not an insulin denier as is obvious from my other blog posts. I'm still restricting my carbohydrate intake to ~125g/day from whole foods.
I'm not a food reward denier. I've been using food reward principles to lose weight.
This post will probably annoy some people. Before wasting your time writing a comment, please read my Moderation Policy.
At first glance, Fig 7A looks like a CIH believer's dream come true (apart from the words "High Fat Diet").
Obesity is caused by too much insulin. Game, Set and Match to insulin.
Not so fast! Let's take a look at the rest of Fig 7.
↑ Peripheral Hyperinsulinemia → ↓ Uncoupling Proteins (WAT) → ↓ Energy Expenditure → ↑ Obesity.
Obesity is caused by a reduction in energy expenditure in these mice. Game, Set and Match to The Energy Balance Equation. It’s the Calories, Stupid. In these mice, energy expenditure is strongly influenced by insulin levels. In humans, not a lot. In humans, insulin can act as a stimulant or a sedative.
I'm not an insulin denier as is obvious from my other blog posts. I'm still restricting my carbohydrate intake to ~125g/day from whole foods.
I'm not a food reward denier. I've been using food reward principles to lose weight.
This post will probably annoy some people. Before wasting your time writing a comment, please read my Moderation Policy.
Monday, 27 February 2012
It's all in a day's work (as measured in Joules) Part 2.
Are you as aerobically-fit as this bloke?
Emmanuel Mutai made it a Kenyan double after winning the Virgin London Marathon in a new course record. Mutai's time of 2:04.38, beats the previous best of 2:05.10 set by Samuel Wanjiru in 2009 and also the fifth-fastest time ever.
I'll take it that's a "no", then.
Elite marathon runners have optimised their metabolisms to use the minimum possible amount of muscle glycogen as fuel. Muscle glycogen storage is limited to ~1,680kcals-worth (~420g of carb)*.
Supercompensation (depletion followed by 3 days of carb-loading) can increase this figure to ~720g*.
Fat storage can amount to ~35,000kcals-worth (~10lb of fat), even in a skinny Kenyan like Mutai.
A blogger called Thor Falk took the data from It's all in a day's work (as measured in Joules) and plotted it as a graph in Fat vs carb burning – a N=1 chart. Here's the graph:-
Even a super-fit Kenyan like Mutai burns some carbs when running at ~12.5 miles per hour. The less fit that somebody is, the more the first corner in the blue plot moves down and to the left. This results in more carbs being burned at energy consumption levels more than the first corner. This depletes muscle glycogen stores faster, resulting in "hitting the wall" (running out of muscle glycogen) sooner.
Muscles that are depleted of glycogen are more insulin-sensitive than muscles that have more glycogen, therefore the less aerobically-fit somebody is, the sooner their muscles become insulin-sensitive when they exercise.
*Assuming 20kg of muscle (Lore of Running P104)
Emmanuel Mutai made it a Kenyan double after winning the Virgin London Marathon in a new course record. Mutai's time of 2:04.38, beats the previous best of 2:05.10 set by Samuel Wanjiru in 2009 and also the fifth-fastest time ever.I'll take it that's a "no", then.
Elite marathon runners have optimised their metabolisms to use the minimum possible amount of muscle glycogen as fuel. Muscle glycogen storage is limited to ~1,680kcals-worth (~420g of carb)*.
Supercompensation (depletion followed by 3 days of carb-loading) can increase this figure to ~720g*.
Fat storage can amount to ~35,000kcals-worth (~10lb of fat), even in a skinny Kenyan like Mutai.
A blogger called Thor Falk took the data from It's all in a day's work (as measured in Joules) and plotted it as a graph in Fat vs carb burning – a N=1 chart. Here's the graph:-
Even a super-fit Kenyan like Mutai burns some carbs when running at ~12.5 miles per hour. The less fit that somebody is, the more the first corner in the blue plot moves down and to the left. This results in more carbs being burned at energy consumption levels more than the first corner. This depletes muscle glycogen stores faster, resulting in "hitting the wall" (running out of muscle glycogen) sooner.Muscles that are depleted of glycogen are more insulin-sensitive than muscles that have more glycogen, therefore the less aerobically-fit somebody is, the sooner their muscles become insulin-sensitive when they exercise.
*Assuming 20kg of muscle (Lore of Running P104)
Saturday, 5 February 2011
It's all in a day's work (as measured in Joules)
Firstly, a relevant video by Flanders and Swann.
The title of this blog post is from the "Physics Man" sketch on The Now Show. Work (also heat) is another word for energy and there are two different units for it.
The calorie (cal) is the amount of energy required to heat 1g of water by 1°C. This is a tiny amount of energy. The dietary Calorie (Cal) = 1,000cal = 1kcal.
The Joule (J) is the SI unit of energy. 1J = 1kg*m^2/s^2.
1Joule/sec = 1Watt (W).
1kcal = 4.186kJ.
At rest, an average human body uses ~1kcal/min = ~4,186J/min = ~69.8J/sec = ~69.8W.
The brain uses ~5g of glucose/hour = 18.75kcal/hour (1g of carb = 3.75kcals, usually rounded-up to 4) = 78487.5J/hour = ~21.8W.
The heart uses ~10W. The liver, kidneys, gut and lungs run continuously so they use energy all of the time.
Skeletal muscle uses a variable amount of energy using a variable proportion of fuels, depending on what you're doing with it. A chap called Steve sent me a spreadsheet of results in 2004 when he underwent a metabolic test on a stationary bike while breathing through a respiratory gas analyser, which calculated kcals oxidised and fuel utilisation by measuring Respiratory Exchange Ratio (RER).
At 1kcal/min (resting), he oxidised ~95% from fat (~0.11g/min), ~5% from carb (~0.01g/min).
At 2kcal/min (12% max), he oxidised 100% from fat (0.22g/min), 0% from carb (0.00g/min).
At 3kcal/min (18% max), he oxidised 100% from fat (0.33g/min), 0% from carb (0.00g/min).
At 4kcal/min (24% max), he oxidised 99% from fat (0.44g/min), 1% from carb (0.01g/min).
At 5kcal/min (29% max), he oxidised 48% from fat (0.27g/min), 52% from carb (0.69g/min).
At 6kcal/min (35% max), he oxidised 62% from fat (0.41g/min), 38% from carb (0.61g/min).
At 7kcal/min (41% max), he oxidised 58% from fat (0.45g/min), 42% from carb (0.78g/min).
At 8kcal/min (47% max), he oxidised 46% from fat (0.41g/min), 54% from carb (1.15g/min).
At 9kcal/min (53% max), he oxidised 42% from fat (0.53g/min), 58% from carb (1.39g/min).
At 10kcal/min (59% max), he oxidised 44% from fat (0.49g/min), 56% from carb (1.49g/min).
At 11kcal/min (65% max), he oxidised 38% from fat (0.46g/min), 62% from carb (1.82g/min).
At 12kcal/min (71% max), he oxidised 41% from fat (0.55g/min), 59% from carb (1.89g/min).
At 13kcal/min (76% max), he oxidised 37% from fat (0.53g/min), 63% from carb (2.18g/min).
At 14kcal/min (82% max), he oxidised 30% from fat (0.47g/min), 70% from carb (2.61g/min).
At 15kcal/min (88% max), he oxidised 14% from fat (0.23g/min), 86% from carb (3.44g/min).
At 16kcal/min (94% max), he oxidised 0% from fat (0.00g/min), 100% from carb (4.27g/min).
At 17kcal/min (100% max), he oxidised 0% from fat (0.00g/min), 100% from carb (4.53g/min).
There are some interesting points about Steve's data:
1. Over a wide range of exercise intensities, the number of grams of fat Steve oxidised/min was fairly constant.
2. Up to 24% of maximum exercise intensity, Steve derived almost 100% of his energy from the oxidation of fat. Steve was on a LC diet, which shifts fuel usage away from carb and towards fat. This is known as "fat-adaptation".
3. Despite fat-adaptation, above about 45% of maximum exercise intensity, Steve derived more energy from the oxidation of carb than the oxidation of fat.
4. Despite fat-adaptation, above about 80% of maximum exercise intensity, Steve derived almost all of his energy from the oxidation of carb rather than the oxidation of fat.
Note that 17kcals/min = 1186.6W, or 1.19kW! Steve was aerobically fit. A less aerobically fit person derives a higher % of energy from the oxidation of carb than an aerobically fit person. This level of exercise intensity can be maintained for a few seconds only, as carb is oxidised both aerobically and anaerobically, which exhausts PhosphoCreatine stores in muscles and also causes an accumulation of lactate in muscles.
Muscle mass is very metabolically-active compared to fat mass, as one pound of fat mass oxidises only about 2kcal a day. See also Dissecting the Energy Needs of the Body – Research Review
See also It's all in a day's work (as measured in Joules) Part 2.
Here's another Physics Man.
The title of this blog post is from the "Physics Man" sketch on The Now Show. Work (also heat) is another word for energy and there are two different units for it.
The calorie (cal) is the amount of energy required to heat 1g of water by 1°C. This is a tiny amount of energy. The dietary Calorie (Cal) = 1,000cal = 1kcal.
The Joule (J) is the SI unit of energy. 1J = 1kg*m^2/s^2.
1Joule/sec = 1Watt (W).
1kcal = 4.186kJ.
At rest, an average human body uses ~1kcal/min = ~4,186J/min = ~69.8J/sec = ~69.8W.
The brain uses ~5g of glucose/hour = 18.75kcal/hour (1g of carb = 3.75kcals, usually rounded-up to 4) = 78487.5J/hour = ~21.8W.
The heart uses ~10W. The liver, kidneys, gut and lungs run continuously so they use energy all of the time.
Skeletal muscle uses a variable amount of energy using a variable proportion of fuels, depending on what you're doing with it. A chap called Steve sent me a spreadsheet of results in 2004 when he underwent a metabolic test on a stationary bike while breathing through a respiratory gas analyser, which calculated kcals oxidised and fuel utilisation by measuring Respiratory Exchange Ratio (RER).
At 1kcal/min (resting), he oxidised ~95% from fat (~0.11g/min), ~5% from carb (~0.01g/min).
At 2kcal/min (12% max), he oxidised 100% from fat (0.22g/min), 0% from carb (0.00g/min).
At 3kcal/min (18% max), he oxidised 100% from fat (0.33g/min), 0% from carb (0.00g/min).
At 4kcal/min (24% max), he oxidised 99% from fat (0.44g/min), 1% from carb (0.01g/min).
At 5kcal/min (29% max), he oxidised 48% from fat (0.27g/min), 52% from carb (0.69g/min).
At 6kcal/min (35% max), he oxidised 62% from fat (0.41g/min), 38% from carb (0.61g/min).
At 7kcal/min (41% max), he oxidised 58% from fat (0.45g/min), 42% from carb (0.78g/min).
At 8kcal/min (47% max), he oxidised 46% from fat (0.41g/min), 54% from carb (1.15g/min).
At 9kcal/min (53% max), he oxidised 42% from fat (0.53g/min), 58% from carb (1.39g/min).
At 10kcal/min (59% max), he oxidised 44% from fat (0.49g/min), 56% from carb (1.49g/min).
At 11kcal/min (65% max), he oxidised 38% from fat (0.46g/min), 62% from carb (1.82g/min).
At 12kcal/min (71% max), he oxidised 41% from fat (0.55g/min), 59% from carb (1.89g/min).
At 13kcal/min (76% max), he oxidised 37% from fat (0.53g/min), 63% from carb (2.18g/min).
At 14kcal/min (82% max), he oxidised 30% from fat (0.47g/min), 70% from carb (2.61g/min).
At 15kcal/min (88% max), he oxidised 14% from fat (0.23g/min), 86% from carb (3.44g/min).
At 16kcal/min (94% max), he oxidised 0% from fat (0.00g/min), 100% from carb (4.27g/min).
At 17kcal/min (100% max), he oxidised 0% from fat (0.00g/min), 100% from carb (4.53g/min).
There are some interesting points about Steve's data:
1. Over a wide range of exercise intensities, the number of grams of fat Steve oxidised/min was fairly constant.
2. Up to 24% of maximum exercise intensity, Steve derived almost 100% of his energy from the oxidation of fat. Steve was on a LC diet, which shifts fuel usage away from carb and towards fat. This is known as "fat-adaptation".
3. Despite fat-adaptation, above about 45% of maximum exercise intensity, Steve derived more energy from the oxidation of carb than the oxidation of fat.
4. Despite fat-adaptation, above about 80% of maximum exercise intensity, Steve derived almost all of his energy from the oxidation of carb rather than the oxidation of fat.
Note that 17kcals/min = 1186.6W, or 1.19kW! Steve was aerobically fit. A less aerobically fit person derives a higher % of energy from the oxidation of carb than an aerobically fit person. This level of exercise intensity can be maintained for a few seconds only, as carb is oxidised both aerobically and anaerobically, which exhausts PhosphoCreatine stores in muscles and also causes an accumulation of lactate in muscles.
Muscle mass is very metabolically-active compared to fat mass, as one pound of fat mass oxidises only about 2kcal a day. See also Dissecting the Energy Needs of the Body – Research Review
See also It's all in a day's work (as measured in Joules) Part 2.
Here's another Physics Man.
Friday, 2 January 2009
Why counting Calories and weighing yourself regularly can be a waste of time.
To lose weight, eat fewer Calories than you burn. Sounds fairly straightforward, doesn't it?
What is a Calorie?
One dietary Calorie (Cal) is 1000calories, or 1kcal for short. A calorie (cal) is the amount of energy required to heat 1g (1mL) of water by 1degree C. As 1cal is a tiny amount of energy, kcal is commonly used. I prefer to use kcal rather than Cal, as the first word in a sentence is always capitalised which could cause confusion.
The SI unit of energy is the Joule (J) and is the amount of energy required to lift a 1kg weight 1m into the air. As 1J is also a tiny amount of energy, kJ is commonly used. There are 4.186kJ in 1kcal.
Why counting Calories can be a waste of time.
1. When the label on a packet of food states that the food contains Xkcals or YkJ, the number may be inaccurate. See Food Composition Analysis and its Implications for Dietary Planning.
2. Many people are hopeless at judging portion sizes, even when using measuring spoons! Watch the following video made by Leigh Peele called Fat Loss Tips! Shocking!
3. People suffer from "The dieter's Paradox", where they erroneously believe that adding something supposedly healthy to Crap-In-A-Bag/Box/Bottle (CIAB) reduces the total number of calories. See The Dieter’s Paradox – Research Review.
4. If people reach their Calorie intake target for the whole day, but it's only 5pm and they're starving hungry, they're going to eat more food and exceed their target, unless they have supreme willpower. If you're eating the wrong diet, Calorie targets are moot. Find a diet where Calorie intake is naturally reduced, without causing hunger pangs.
Why weighing yourself regularly can be a waste of time.
As mentioned previously, scales cannot distinguish between muscle, body-fat, glycogen+water, urine, faeces etc. Bodyweight can fluctuate considerably on a day-to-day basis. The following list (source forgotten!) lists the effect of various things on body-weight.
Thing________________________Weight change (lb)
Glycogen supercompensation________~+10
Glycogen replenishment/depletion_+/-4 to 5
Pre-menstrual water retention_____~+5
Eating a high-sodium meal__________+2 to 3
Fluid retention on airplane flight +2 to 3
Going to the loo (No.2)____________-1 to 2
Going to the loo (No.1)___________~-0.5
Drinking a mug of tea_____________~+0.5
So step away from the scales. There's nothing to see here, folks! If your belt/clothes are getting tighter, reduce the frequency of eating "treats" (moreish foods that are usually high in sugar, fat, salt & flavourings).
And finally, a little light relief. If I just waffle on about Diet & Nutrition all the time, it can get boring. So here's a YouTube video of a really cool cat that must have watched the Doctor Who episode "Blink". You know, the one with the Weeping Angels. Ninja cat comes closer while not moving!
What is a Calorie?
One dietary Calorie (Cal) is 1000calories, or 1kcal for short. A calorie (cal) is the amount of energy required to heat 1g (1mL) of water by 1degree C. As 1cal is a tiny amount of energy, kcal is commonly used. I prefer to use kcal rather than Cal, as the first word in a sentence is always capitalised which could cause confusion.
The SI unit of energy is the Joule (J) and is the amount of energy required to lift a 1kg weight 1m into the air. As 1J is also a tiny amount of energy, kJ is commonly used. There are 4.186kJ in 1kcal.
Why counting Calories can be a waste of time.
1. When the label on a packet of food states that the food contains Xkcals or YkJ, the number may be inaccurate. See Food Composition Analysis and its Implications for Dietary Planning.
2. Many people are hopeless at judging portion sizes, even when using measuring spoons! Watch the following video made by Leigh Peele called Fat Loss Tips! Shocking!
3. People suffer from "The dieter's Paradox", where they erroneously believe that adding something supposedly healthy to Crap-In-A-Bag/Box/Bottle (CIAB) reduces the total number of calories. See The Dieter’s Paradox – Research Review.
4. If people reach their Calorie intake target for the whole day, but it's only 5pm and they're starving hungry, they're going to eat more food and exceed their target, unless they have supreme willpower. If you're eating the wrong diet, Calorie targets are moot. Find a diet where Calorie intake is naturally reduced, without causing hunger pangs.
Why weighing yourself regularly can be a waste of time.
As mentioned previously, scales cannot distinguish between muscle, body-fat, glycogen+water, urine, faeces etc. Bodyweight can fluctuate considerably on a day-to-day basis. The following list (source forgotten!) lists the effect of various things on body-weight.
Thing________________________Weight change (lb)
Glycogen supercompensation________~+10
Glycogen replenishment/depletion_+/-4 to 5
Pre-menstrual water retention_____~+5
Eating a high-sodium meal__________+2 to 3
Fluid retention on airplane flight +2 to 3
Going to the loo (No.2)____________-1 to 2
Going to the loo (No.1)___________~-0.5
Drinking a mug of tea_____________~+0.5
So step away from the scales. There's nothing to see here, folks! If your belt/clothes are getting tighter, reduce the frequency of eating "treats" (moreish foods that are usually high in sugar, fat, salt & flavourings).
And finally, a little light relief. If I just waffle on about Diet & Nutrition all the time, it can get boring. So here's a YouTube video of a really cool cat that must have watched the Doctor Who episode "Blink". You know, the one with the Weeping Angels. Ninja cat comes closer while not moving!
Saturday, 20 December 2008
Everyone is Different.
If there's one thing I've learned over the years of research into Diet and Nutrition, it's this: Everyone is Different. When I first discovered low-carbohydrate diets (thanks to the late Dr Robert C. Atkins M.D.), I thought that it was the One True Diet, and I became a bit of an "Atkins bore" telling everyone how wonderful it was and suggesting that everyone should be on it. I now know that what suits me* doesn't necessarily suit everyone else.
*It only suited me because I had Insulin Resistance/Metabolic Syndrome/Syndrome-X. I reversed it in 2008. See Insulin Resistance: Solutions to problems for how I did it.
Here's Fig. 2 from Determinants of the variability in respiratory exchange ratio at rest and during exercise in trained athletes. Used with permission.
Respiratory Exchange Ratio (RER) (a.k.a. Respiratory Quotient (RQ)) is the ratio of carbon dioxide breathed out to oxygen breathed in. This ratio depends on the fuels that the body is burning for energy. For example, if the body is burning 100% fats, RER = 0.7. If the body is burning 100% carbohydrates aerobically, RER=1.0. If the body is burning 100% carbohydrates, with some aerobically and some anaerobically (e.g. sprinting flat-out), RER > 1.0. To understand why this is so, see Respiratory Exchange Ratio (RER) explained.
RER varies with intensity of exercise, food intake (increasing protein &/or carbohydrate intake increases it and fasting or reducing protein &/or carbohydrate intake reduces it) and cardiovascular fitness. Increasing cardiovascular fitness reduces RER.
The top diagram is a histogram of fasted RER and % fat oxidation vs. number of subjects. At the left-hand end of the histogram, there are two cyclists with a fat oxidation of 93 - 100%. At the right-hand end of the histogram, there is one cyclist with a fat oxidation of 20 - 27%. Average fat oxidation is ~60%.
As exercise intensity increases, the peak in the histogram shifts to the right as shown in the lower diagram. At 25% of maximum intensity, mean fat oxidation is ~53%. At 50% of maximum intensity, mean fat oxidation is ~37% and at 75% of maximum intensity, mean fat oxidation is ~13%. At maximum intensity, mean fat oxidation is ~0% i.e. 100% of energy is obtained from carbohydrates when sprinting flat-out. Somebody on a very-low-carbohydrate, high fat ketogenic diet e.g. Atkins induction (~20g net carbs/day) could keel over with hypoglycaemia if they exercise for too long at too high an intensity.
As there is variation from person to person, you must find out for yourself your own optimum proportions of proteins, fats & carbohydrates, and these depend upon the intensity & volume of exercise you do. It sounds complicated, but it isn't really.
Apply the principle of "Eat, monitor & adjust accordingly" as Toxic Toffee (ex-Muscletalk member) always used to say. The eating bit will be covered in future Blog posts. The monitoring bit doesn't necessarily involve bathroom scales.
Hang on. Isn't "dieting" all about losing excess weight? Not necessarily. Remember the old joke?
Q. What's the best way to lose 5lbs of ugly flab?
A. Cut off your head.
As your body contains water, muscle, bodyfat, bones, cartilage, tendons, organs, glycogen, skin etc and your scales can't tell the difference between them, losing weight the wrong way can make you less healthy. However, losing weight the right way will make you more healthy.
If you starve, skip breakfast or go for a long run before breakfast, as your body is lacking glycogen reserves & amino acids, a large amount of a corticosteroid hormone called cortisol is secreted, which increases the conversion of muscle into amino acids, then glucose. As muscle has an energy density of ~600kcal/lb, a deficit of 3,500kcal (which would result in a bodyfat loss of 1lb) results in a muscle loss of 5.8lb. For more information, see The Energy Balance Equation.
Chronically-high cortisol also suppresses the immune system and weakens skin & bones.
Unless you have a lot of muscle mass to spare, it's bodyfat that you should be losing, and to monitor this, either use a tape-measure around your waist, check how loose/tight your clothes are, or strip-off and jump up & down in front of a full-length mirror. As Big Les (Muscletalk Moderator) says, "If it jiggles, it's fat.".
2016 EDIT: Scales that can calculate bodyfat % etc are now inexpensive, e.g. Body Analysis Scale.
So, what happens if you eat too much carbohydrate but your body doesn't burn it fast enough? Initially, carbohydrate intake tops-up liver and muscle glycogen stores, which increases carbohydrate-burning to compensate. The liver can store about 70g of glycogen and muscles can store about 400g of glycogen. If, despite increased carbohydrate-burning, more carbohydrate is consumed than is burned, glycogen stores continue to fill. When glycogen stores become full, RER increases to 1.0 and 100% of energy is derived from carbohydrate. Getting 100% of energy from carbohydrate means that zero fat is burned, so keeping glycogen stores filled to the brim by chronically overeating carbohydrate is not a good idea if you want to burn some body-fat.
Once glycogen stores are full, any additional intake of carbohydrate beyond that which is burned passes through the lipogenesis pathway - this basically means that carbs are turned into fat - which may end up as liver fat. But there's even worse news. Fat is secreted by the liver into the blood as triglycerides. This is bad for the cholesterol particles in your blood. See Cholesterol and Coronary Heart Disease. What happens if you eat too few carbs? As stated above, someone exercising at a highish intensity taking in insufficient carbohydrates could get hypoglycaemia & keel over.
How many grams of carbohydrate per day does it take to promote lipogenesis? Someone at rest burns ~1kcal/minute. If this is derived 100% from carbohydrate, this is equivalent to 0.25g of carbohydrate/minute, or 15g of carbohydrate/hour, or 360g of carbohydrate/day. Therefore, sedentary people who chronically consume more than 360g of carbohydrate/day may produce significant triglycerides. People who have The Metabolic Syndrome/Syndrome-X (a high proportion of people who have excess belly fat) have increased lipogenesis and higher serum triglycerides than healthy people.
Discussing weight again for a moment, it's often said that all diets are the same, as weight loss is all about calories. This is true. See Is a Calorie a Calorie? However, body composition is determined by a combination of macro-nutrient proportions (i.e. the relative amounts of proteins, carbohydrates and fats in the diet) and the intensity & volume of exercise. Health is determined by a combination of micro-nutrient proportions (i.e. vitamins, minerals & anutrients) and exercise. See On burning, storing and recomposing.
If you're only interested in weight loss, just count calories. If you wish to lose bodyfat without losing muscle mass, you need to know what proportions of proteins, carbohydrates & fats to eat (it's really not that critical, but many people get it wrong). You need to know the difference between good carbs & bad carbs, and good fats & bad fats. You need to know the best times to eat proteins, carbohydrates & fats relative to exercise (it's also really not that critical, but many people get it wrong). You need to know the difference between good exercise & bad exercise.
Continued on We are not all the same.
*It only suited me because I had Insulin Resistance/Metabolic Syndrome/Syndrome-X. I reversed it in 2008. See Insulin Resistance: Solutions to problems for how I did it.
Here's Fig. 2 from Determinants of the variability in respiratory exchange ratio at rest and during exercise in trained athletes. Used with permission.
Respiratory Exchange Ratio (RER) (a.k.a. Respiratory Quotient (RQ)) is the ratio of carbon dioxide breathed out to oxygen breathed in. This ratio depends on the fuels that the body is burning for energy. For example, if the body is burning 100% fats, RER = 0.7. If the body is burning 100% carbohydrates aerobically, RER=1.0. If the body is burning 100% carbohydrates, with some aerobically and some anaerobically (e.g. sprinting flat-out), RER > 1.0. To understand why this is so, see Respiratory Exchange Ratio (RER) explained.
RER varies with intensity of exercise, food intake (increasing protein &/or carbohydrate intake increases it and fasting or reducing protein &/or carbohydrate intake reduces it) and cardiovascular fitness. Increasing cardiovascular fitness reduces RER.
The top diagram is a histogram of fasted RER and % fat oxidation vs. number of subjects. At the left-hand end of the histogram, there are two cyclists with a fat oxidation of 93 - 100%. At the right-hand end of the histogram, there is one cyclist with a fat oxidation of 20 - 27%. Average fat oxidation is ~60%.
As exercise intensity increases, the peak in the histogram shifts to the right as shown in the lower diagram. At 25% of maximum intensity, mean fat oxidation is ~53%. At 50% of maximum intensity, mean fat oxidation is ~37% and at 75% of maximum intensity, mean fat oxidation is ~13%. At maximum intensity, mean fat oxidation is ~0% i.e. 100% of energy is obtained from carbohydrates when sprinting flat-out. Somebody on a very-low-carbohydrate, high fat ketogenic diet e.g. Atkins induction (~20g net carbs/day) could keel over with hypoglycaemia if they exercise for too long at too high an intensity.
As there is variation from person to person, you must find out for yourself your own optimum proportions of proteins, fats & carbohydrates, and these depend upon the intensity & volume of exercise you do. It sounds complicated, but it isn't really.
Apply the principle of "Eat, monitor & adjust accordingly" as Toxic Toffee (ex-Muscletalk member) always used to say. The eating bit will be covered in future Blog posts. The monitoring bit doesn't necessarily involve bathroom scales.
Hang on. Isn't "dieting" all about losing excess weight? Not necessarily. Remember the old joke?
Q. What's the best way to lose 5lbs of ugly flab?
A. Cut off your head.
As your body contains water, muscle, bodyfat, bones, cartilage, tendons, organs, glycogen, skin etc and your scales can't tell the difference between them, losing weight the wrong way can make you less healthy. However, losing weight the right way will make you more healthy.
If you starve, skip breakfast or go for a long run before breakfast, as your body is lacking glycogen reserves & amino acids, a large amount of a corticosteroid hormone called cortisol is secreted, which increases the conversion of muscle into amino acids, then glucose. As muscle has an energy density of ~600kcal/lb, a deficit of 3,500kcal (which would result in a bodyfat loss of 1lb) results in a muscle loss of 5.8lb. For more information, see The Energy Balance Equation.
Chronically-high cortisol also suppresses the immune system and weakens skin & bones.
Unless you have a lot of muscle mass to spare, it's bodyfat that you should be losing, and to monitor this, either use a tape-measure around your waist, check how loose/tight your clothes are, or strip-off and jump up & down in front of a full-length mirror. As Big Les (Muscletalk Moderator) says, "If it jiggles, it's fat.".
2016 EDIT: Scales that can calculate bodyfat % etc are now inexpensive, e.g. Body Analysis Scale.
So, what happens if you eat too much carbohydrate but your body doesn't burn it fast enough? Initially, carbohydrate intake tops-up liver and muscle glycogen stores, which increases carbohydrate-burning to compensate. The liver can store about 70g of glycogen and muscles can store about 400g of glycogen. If, despite increased carbohydrate-burning, more carbohydrate is consumed than is burned, glycogen stores continue to fill. When glycogen stores become full, RER increases to 1.0 and 100% of energy is derived from carbohydrate. Getting 100% of energy from carbohydrate means that zero fat is burned, so keeping glycogen stores filled to the brim by chronically overeating carbohydrate is not a good idea if you want to burn some body-fat.
Once glycogen stores are full, any additional intake of carbohydrate beyond that which is burned passes through the lipogenesis pathway - this basically means that carbs are turned into fat - which may end up as liver fat. But there's even worse news. Fat is secreted by the liver into the blood as triglycerides. This is bad for the cholesterol particles in your blood. See Cholesterol and Coronary Heart Disease. What happens if you eat too few carbs? As stated above, someone exercising at a highish intensity taking in insufficient carbohydrates could get hypoglycaemia & keel over.
How many grams of carbohydrate per day does it take to promote lipogenesis? Someone at rest burns ~1kcal/minute. If this is derived 100% from carbohydrate, this is equivalent to 0.25g of carbohydrate/minute, or 15g of carbohydrate/hour, or 360g of carbohydrate/day. Therefore, sedentary people who chronically consume more than 360g of carbohydrate/day may produce significant triglycerides. People who have The Metabolic Syndrome/Syndrome-X (a high proportion of people who have excess belly fat) have increased lipogenesis and higher serum triglycerides than healthy people.
Discussing weight again for a moment, it's often said that all diets are the same, as weight loss is all about calories. This is true. See Is a Calorie a Calorie? However, body composition is determined by a combination of macro-nutrient proportions (i.e. the relative amounts of proteins, carbohydrates and fats in the diet) and the intensity & volume of exercise. Health is determined by a combination of micro-nutrient proportions (i.e. vitamins, minerals & anutrients) and exercise. See On burning, storing and recomposing.
If you're only interested in weight loss, just count calories. If you wish to lose bodyfat without losing muscle mass, you need to know what proportions of proteins, carbohydrates & fats to eat (it's really not that critical, but many people get it wrong). You need to know the difference between good carbs & bad carbs, and good fats & bad fats. You need to know the best times to eat proteins, carbohydrates & fats relative to exercise (it's also really not that critical, but many people get it wrong). You need to know the difference between good exercise & bad exercise.
Continued on We are not all the same.
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