The Protein-Sparing Modified Fast (PSMF)

What's a PSMF?

A standard PSMF is ~1g of protein for every kg bodyweight per day plus lots of green leafy vegetables plus six to ten fish oil capsules per day plus vitamin and mineral supplements plus unlimited water AND NOTHING ELSE. It's a low-carbohydrate and low-fat diet. You may find this quite literally hard to swallow! PSMF may also stand for Protein Strictly , Mother-F***er!

A 100kg person may get to eat ~400kcals per day from protein + ~100kcals per day from incidental carbohydrates and fats = ~500kcals per day.

A well-known PSMF is Lyle McDonald's Rapid Fat Loss Handbook. For more information, see https://forums.lylemcdonald.com/forumdisplay.php?f=7 and Is Rapid Fat Loss Right For You?

To make a PSMF easier to manage (but have a slower rate of weight loss), here are some modifications:-

1) Instead of six to ten fish oil capsules a day, stir ~25g of powdered linseeds into a large glass of drink and swallow the lot. Do this at breakfast-time. ~25g of linseeds contains ~10g of fat (of which ~6g is Alpha-Linolenic Acid, an omega-3 fatty acid) which does the following:-

a) It stimulates the gall-bladder to empty, thus reducing the risk of gallstones.
b) a) usually results in a bowel movement some time later. The ~10g of soluble fibre/fiber in the linseeds + accompanying fluid guarantees regularity.
c) It provides women (but not men) with all of the omega-3 fat they need each day.

Men need to eat either half a 213g tin of wild red salmon per day, or take six to ten fish oil capsules a day, as their bodies don't produce enough DHA from Alpha-Linolenic Acid. See Eicosapentaenoic and docosapentaenoic acids are the principal products of α-linolenic acid metabolism in young men and Extremely Limited Synthesis of Long Chain Polyunsaturates in Adults: Implications for their Dietary Essentiality and use as Supplements

2) Eat about 100g of protein per day. As meat, poultry and fish contains 20-25% protein, this means that you can eat ~1lb of meat, poultry and fish a day. 100g of protein per day is well within the capabilities of your liver and kidneys.

3) Eat about 22g of fat per day. This allows you to choose less lean cuts of meat and poultry, and you can even eat the skin on chicken as long as you factor it into your total fat allowance. It also allows you to use vinaigrette salad dressings or a small knob of butter or a small dollop of real mayonnaise to make your vegetables taste nicer.

4) Eat about 50g of carbohydrate per day. This allows you to eat shed-loads of leafy green vegetables and also an onion. It also allows you to eat a portion of fruit e.g. an apple or a bowl of berries/cherries with Splenda and a small dollop of whipped cream each day.

5) If you do any intense exercise (e.g. HIIT or resistance training with weights), eat an extra 50g of slow-release carbohydrates a couple of hours beforehand, to fuel it.

6) Supplement with 50iu for every kg bodyweight per day of Vitamin D3. Nowadays, many of us spend our lives mostly indoors, and this causes sub-optimal Vitamin D levels. See Vitamin D.

7) Don't get too far away from a toilet. Rapid depletion of muscle and liver glycogen results in rapid shedding of associated water. In addition, the oxidation of fatty acids results in the production of water. A PSMF makes you pee more.

n*CH2 + 3/2*n*O2 = n*CO2 + n*H2O + heat

(Saturated fatty acids are CH3-n*CH2-COOH. For Stearic acid, n=16. ∴ Stearic acid is mostly n*CH2. )


In conclusion:

100g of protein provides 400kcals, 22g of fat provides 200kcals and 50g of carbohydrate provides 200kcals, making a grand total of 800kcals per day. If you weigh over 80lbs but aren't losing weight on 800kcals per day, see your GP as you may have a thyroid problem.

The above diet should avoid the problems of gallstones, constipation, dry skin, dry hair, depression and dietary deficiencies. You get to eat real food and quite a lot of it too, for a fairly rapid fat loss diet.