Low Calorie Diet Reduces Core Body Temperature

Experimental analysis has shown higher lifespan in animals with reduced core body temperature. This study was performed to compare the core body temperature in sedentary people, those who exerted themselves, and those who were on restricted diets. The core temperature was recorded every minute for 24 hours, in the study participants. It was found that those who were on restricted diets and those who exerted themselves weighed less than the sedentary people. However, the mean 24-hour core body temperatures were lower in the group that was on the restricted diet. The results were similar to the animal experiments and likewise, could influence the slow rate of aging.

It has been shown in mice and monkeys that calorie restriction could increase the lifespan as well as the quality of health. A study conducted on men with lower core body temperatures showed that they had a longer lifespan. The temperature of the body is controlled by certain centers in the brain. Certain cellular adaptations, which also help to reduce the core body temperature, could induce anti-aging effects as a result of calorie restriction. The effects of calorie restriction without malnutrition on the core body temperature have not been studied until now. Thus, this study was performed to compare the temperatures between those who were on low caloric diets, those who performed exercises, and those who had a sedentary lifestyle being used as a control group.


  • There were 24 participants in each group. The calorie-restricted group comprised people from the Calorie Restriction Society. The participants in the exercise group were endurance runners and the sedentary participants were those who weighed normal and were on western diets.
  • All the participants completed a survey on their food habits and had their fat composition measured.
  • A 24-hour core body temperature monitoring was recorded from a wireless temperature sensor, which the participants had ingested. The mean day and night temperatures were calculated and the data were analyzed.


  • The body fat content in lower calorie intake and exercise groups was nearly 15%. But the sedentary group had an average body fat content of 21%.
  • The energy intake was significantly lower in the calorie-restricted group (1769±348 kcal/d) than those in the exercise group (2798±760 kcal/d) or the sedentary group (2302±668 kcal/d).
  • The mean 24-hour core body temperatures were 36.64°C, 36.86°C and 36.83°C on average in the calorie-restricted group, the exercise group and the sedentary group, respectively.

Shortcomings/Next steps
Authors agree that mean 24-hour, day-time and night-time core body temperatures are all significantly lower in the calorie-restricted group than in the sedentary group and exercise group. Based on the fact and finding that lower temperatures were seen only in the group with calorie restriction and not in those performing the endurance exercises, there have been a few contradictions in the studies being performed previously.

This study correlates findings on diet restriction, body fat content, and 24-hour core body temperature. It is seen that the likely reduction in core body temperature is attributed to calorie restriction rather than the fat content. Though both the exercise group and the group on reduced caloric intake had similar fat content, the core body temperature was ~0.2°C lower in the latter group. The lower temperatures could induce energy conservation mechanisms in the body and lower the levels of thyroid hormones, finally reducing certain cellular stresses and also help to delay the aging process. Thus, long-term caloric reduction, but with adequate nutrient intake and maintenance of a stable weight, can lead to the reduction in the 24-hour core body temperature with a possible positive influence on aging.

For More Information:
Long-term Calorie Restriction Lowers Core Body Temperature
Publication Journal: Aging, March 2011
By Andreea Soare, Roberto Cangemi
From the Washington University School of Medicine, St. Louis, Missouri; University Campus Bio-Medico, Rome, Italy; University of Rome “La Sapienza,” Italy

*FYI Living Lab Reports Are Summaries of the Original Research.

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