It's been known for a long time that starving rats and mice (and fruitflies and many other animals) results in a significant increase in life-span. Now, a study came out that shows similar effects in humans. To oversimplify the results of the study, increased use of energy (excercise) did not have the effect, while comparable decrease in the intake of energy (diet) had the desired effect:
Low-Calorie Diet May Lead to Longer Life
Among the main findings of Dr. Ravussin's study was that calorie restriction led to decreases in insulin levels and body temperature. Both are considered signs of longevity, partly because an earlier study by other researchers found both traits in long-lived people. The diet also led to a drop in thyroid hormones and declines in DNA damage.Read the whole thing, of course....
I could not find the paper yet, but judging from the article, as well as from the interview on Science Friday on NPR today, they did not measure daily fluctuations in body temperature. If you have read this post of mine, you will recall that complete food deprivation (no food at all for a couple of days) tends to result in a drop of body temperature only during the night, while food restriction (low-calorie diet over a longer period of time) results in a drop of body temperature both day and night. If you get a hold of the paper, will you please send me the PDF by e-mail, please.