Got to thinking this at lunch…
I’m exercising and losing weight*. If I eat a lot, I will gain weight. The human body requires a certain amount of energy each day to function, and excess energy carried in our food is either stored as fat or left in the food to be excreted.
So… do people in cold climates need more energy on a daily basis to stay alive than people in warm climates? If it takes X amount of food to keep me warm in a cold climate without losing or gaining fat, will I gain fat if I eat the same amount and type of food in a warm climate?
[sub]Mass, actually. It’s not like the gravity is changing around here or anything.[/sub]
I’m not an expert, but I’d guess that your body would have to work pretty hard to stay warm, over a long period of time, in order to burn a significant number of calories.
Most of us would do anything to stay warm.
It also takes energy to stay cool.
The human body requires a paltry am’t of calories to sustain life, and modest differences in temperature from the ideal temperature (in the 70s?) require very little in terms of calories.
In other words, exposing your body to cold temps, or ingesting ice water that requires energy to bring it up to temp, might amount to an additional bite or two each day. It won’t have any real effect on your caloric intake/weight.
missed the edit window:
For short periods of time, your body could use huge am’t of energy to stay warm. The problem is that it can’t go on indefinitely (hypothermia). In short burts, you could probably shed a pound over a 1-3 day stretch of extreme cold (stuck in arctic blast while mountain climbing), where your energy is spent staying warm. And that is a pretty good guess based on how fast you can possibly lose weight and how many calories go into each pound of fat.
What you are doing is exchanging movement for cold. If you hunker down and your body fights to stay warm for 2-3 days you might shed a pound. Conversely, if you were active and pushing your body hard for 2-3 days you could lose a pound that way.
A quick Google led to some inconclusive results. The US Army provides 25-50% more calories to its troops engaged in cold-weather activities, but attributes most of the excess calorie expenditure to the increased difficulties in movement caused by cold weather – heavy clothes, snow, and so on. This study of men in the Antarctic indicates that caloric intakes exceeded output during the winter months. But it’s hard to interpret because it appears that during the winter, the personnel pretty much stayed indoors and didn’t do much exercise. So they weren’t necessarily out in the cold doing stuff. And most studies are assuming the subjects are dressed for the cold, therefore not radiating heat willy-nilly.
So…yeah, probably in cold weather you burn more calories than in warm. But this is counteracted by the fact that in cold weather anyone with any sense is at home in front of the fire and not exercising.