Kanazawa, Satoshi (2019). Does global warming contribute to the obesity epidemic?. Environmental Research.
Endotherms must expend more energy to digest colder food, so they acquire more calories by eating food at a higher temperature than eating the identical food cold. A recent study shows that ownership of a microwave is associated with a small increase in BMI and obesity. The same logic applies to other substances that endotherms introduce into their bodies, like air. An analysis of the National Longitudinal Study of Adolescent to Adult Health (Add Health) shows that, net of sex, age, race, education, earnings, neighborhood characteristics, and exercise activities, atmospheric temperature is associated with small but statistically significant increases in BMI, weight, overweight, and obesity. Atmospheric temperature is more strongly associated than most exercise activities, and as strongly associated as age and population density. An average American might reduce weight by 15.1 lbs, BMI by 2.52 (half the difference between normal weight and obesity), and the odds of obesity by 54% by moving from Phoenix, AZ, to Barrow, AK, or, less dramatically, 5.7 lbs in weight, .95 in BMI (a fifth of the difference between normal weight and obesity), and 25% in the odds of obesity by moving mere 150 miles north to Flagstaff, AZ. Global warming under the worst-case scenario might produce an increase of 2.2 lbs in weight, .37 in BMI, and 12% in odds of obesity from 1961 to 2081.
Specific dynamic action