Humans in the cold: Regulating energy balance

Area of Science:

• Physiology
• Metabolism
• Environmental Health

Background:

• Maintaining core body temperature in cold environments necessitates increased energy expenditure (EE).
• Energy intake (EI) responses to cold exposure (CE) are less understood, despite their importance for overall energy balance.
• Existing research primarily focuses on EE, overlooking the impact of CE on EI.

Purpose of the Study:

• To review the current understanding of how cold exposure affects both energy expenditure and energy intake.
• To identify gaps and limitations in the existing literature on cold exposure and energy balance.
• To evaluate the potential of cold exposure as a weight loss strategy.

Main Methods:

• Review of existing scientific literature on cold exposure, energy expenditure, and energy intake in animal models and humans.
• Analysis of dose-response effects in animal studies.
• Examination of human studies involving acute and chronic cold exposure, including measurements of ad libitum food intake.

Main Results:

• Animal models show significant increases in EE and a negative dose-response effect on EI with decreasing temperatures (r=-.787, P<.001).
• Human studies demonstrate consistent but small increases in EE with acute cold exposure.
• Limited human data exists for EI during acute CE, and chronic CE shows minimal body weight changes with substantial energy compensation (~126%).

Conclusions:

• Cold exposure significantly impacts energy expenditure but its effect on energy intake in humans requires further investigation.
• Current evidence suggests that cold exposure alone may not be an effective strategy for weight loss.
• More research is needed to fully elucidate the complex relationship between cold exposure and human energy balance.