I posted this in another thread and thought it would be appropriate here also.

Lack of vitamin D May Cause Stalls

Winter stalls are very common. For a lot of people, the body just refuses to give up weight/fat during winter regardless of calorie or exercise level. In fact I think lowering calories and upping exercise, for these people, during winter just encourages the body to hold on to weight even more tenaciously. To the body, fat stores in winter means survival to spring and the body's primary goal is survival and therefore hoarding fat stores.

Studies have found that many people, and animals of course, naturally start gaining fat stores in fall and releasing them in spring. It's a natural cycle.

In order to achieve adequate fat levels, especially after losing weight which can mean starvation to the body, the body can actually cause/use cravings to have you consume carbohydrates which are then converted to fat stores, i.e., better chances of survival. Further the body will also lower metabolic rate to conserve those same fat cells. These body behaviors can lead to rapid weight/fat gain.

The body is a very primitive machine. It doesn't know or care that you want to lose weight. It just knows you have lost weight, so you must have survived famine, and you are coming into winter. It's just trying to ensure your survival.

Something else to think about:

Perceived Winter: If most of your life is spent in doors out of the sun or you habitually use sunscreen when outside (sunscreen of even SPF8 reduces the ability to generate vitamin D by over 85%) then your body might still consider you in winter and subject to death by starvation and so might still hoard fat stores.

See, adequate vitamin D=adequate sun=winter's over=you survived=the body can safely release fat.

In the obese, a percentage of vitamin D generated or consumed in captured in body fat and so is not bioavailable to the body. Therefore the obese need 2-3 times the vitamin D of a normal weight individual. 83% of obese patients tested were vitamin D deficient, and that was using a deficiency level of <35. When the scale was moved to <50, the percentage of the obese who with readings under that level was 95%.

The latest research concludes that vitamin D levels for good health and protection against cancers should be >75.