Core temperature: a forgotten variable in energy expenditure and obesity?

Area of Science:

• Metabolic regulation and energy expenditure
• Thermoregulation in mammals
• Obesity research

Background:

• Maintenance of the homoeothermic state accounts for a significant portion of human energy expenditure (~40%).
• Mammalian species use regulated hypothermia (e.g., torpor, hibernation) for energy conservation.
• Rodent models of inherited obesity exhibit lower core temperatures and cold intolerance, unlike obese humans with normal temperatures.

Purpose of the Study:

• To review the role of core body temperature in the metabolic economy of obesity.
• To investigate the potential link between lower temperatures and increased metabolic efficiency during weight loss in obese individuals.
• To explore the hypothesis that reduced core temperatures may initiate weight gain in the pre-obese state.

Main Methods:

• Literature review and synthesis of existing research on thermoregulation, energy expenditure, and obesity.
• Comparative analysis of temperature regulation in obese humans versus rodent models of obesity.
• Theoretical exploration of the impact of core temperature on metabolic efficiency and energy balance.

Main Results:

• Obese humans typically maintain normal core body temperatures, contrasting with cold-intolerant obese rodents.
• The review posits that lower core temperatures could enhance metabolic efficiency during weight loss.
• It is suggested that reduced core temperatures might precede weight gain, with normal temperatures in obese individuals acting as compensation.

Conclusions:

• Core body temperature is a critical factor in the metabolic economy of obesity.
• Lowering core temperature may be a mechanism for energy conservation in obese states, potentially aiding weight loss.
• Normal core temperatures in obese individuals may represent a compensatory metabolic adaptation to prevent further weight gain.