On a messageboard in a galaxy far far away, someone suggested that as many as one in three people in the UK could have impaired carbohydrate metabolism. This set me thinking.
London is 51degrees North of the Equator, so the sun has to pass through ~45% more atmosphere to reach us, compared to the Equator.
According to Elina Hyppönen & Chris Power, (edited) "The prevalence of hypovitaminosis D was highest during the winter and spring, when 25(OH)D concentrations less than 75nmol/L were found in 87.1% of participants, respectively; the proportion was 60.9%, respectively, during the summer and autumn."
Note that 75nmol/L was insufficient to give me normal Insulin Sensitivity. See Chiu, Chu, Go & Saad. However, greater than 160nmol/L was sufficient, but that was only obtained after I supplemented with 5,000iu/day of Vitamin D3 (25 x RDA).
A deficiency of omega-3 EFAs can cause Insulin Resistance (poor Insulin Sensitivity). See Ghafoorunissa, Ahamed Ibrahim, Laxmi Rajkumar & Vani Acharya, Storlien LH, Kraegen EW, Chisholm DJ, Ford GL, Bruce DG & Pascoe WS and Yam D, Bott-Kanner G, Friedman J, Genin I, Klainman E & Shinitzky M.The typical omega-6:omega-3 ratio in the British diet is ~15:1. This is partly due to the fact that animal produce from grain-fed animals contains a lot more omega-6 and a lot less omega-3 than it used to. See Is food less nutritious than it used to be? Andre Purvis investigates. In addition, people eat grains, nuts, seeds, oils & spreads high in omega-6 and don't eat much oily fish, powdered Flax-seeds (a.k.a. Linseeds) or Purslane (a plant that's relatively high in omega-3).
With all of these problems, I wonder what percentage of the UK population actually do have some degree of impaired carbohydrate metabolism? It might be more than one in three.
According to The eatwell plate, one third of our total Calories are supposed to come from bread, rice, potatoes, pasta and other starchy foods. Some of these foods rapidly raise blood glucose a lot. Impaired carbohydrate metabolism makes for roller-coaster blood glucose levels which encourages over-eating, leading to obesity (see my Blog post on Blood Glucose, Insulin & Diabetes.)
I think that that's enough thinking for now.