SAD doesn’t just represent the standard American diet.
There is a condition known as seasonal affective disorder which is characterized due to increased appetite and cravings, as well as increased drowsiness and lethargy, which begins in autumn when light exposure begins to decrease. This now seems represent the other end of a normal spectrum of human behavior. We seem to eat more as the days get shorter. There is a “marked seasonal rhythm” in calorie intake with increased meal size, eating rhythm, hunger, and overall caloric intake in the fall.
In preparation for winter, some animals hibernate, doubling their fat reserves with the autumn abundance to cope with the subsequent winter scarcity. The genes have been identified in humans that are similar to hibernation genes, which may help explain why we exhibit some of the same behaviors and the fall effect it’s not subtle. As you can see in the graph below and at 1:06 of my video. Friday Favorites: Why People Gain Weight in the Fall researchers calculated a difference of 222 calories between the amount of calories we consume in the fall and the spring. This is not just because it is colder, either, since we eat more in autumn than in winter. It seems that we are genetically programmed to prepare ourselves for the deprivation of winter that no longer comes.
It is surprising that, in this age of modern lighting and heating, our bodies still choose enough environmental signals of seasonal changes to have such a significant influence on our eating patterns. As expected, bright light therapy is used to treat seasonal affective disorder, almost tripling the probability of remission, compared to placebo. Although it has never been tested directly, it doesn’t hurt to take the dog out for a few extra walks in the morning and during the day in the fall to try to fend off the weight gain that is coming during the holiday season.
People blame holidays for overeating, but it is possible that “rather than the holidays causing an increase in intake, the seasonal increase in intake in the fall may have caused holiday scheduling at that time.”
Anyway, as you can see below and at 2:15 in my videoother “specific recommendations for the prevention of obesity and metabolic syndrome through getting better the health of the circadian system,” according to varying degrees of evidence, include: sleeping at night and being active during the day; get enough sleep, at least seven or eight hours a night; early to sleep, early to get up; and short naps are fine. (Contrary to popular belief, daytime naps do not appear to negatively affect nighttime sleep.) Also recommended: avoiding exposure to bright light at night; sleep in total darkness when possible; make breakfast or lunch your most important meal of the day; not eating or exercising right before bed; and completely avoiding eating at night.
This was the last video in my chronobiology series. If you missed any of the others, check out the related posts below.
