Balancing energy expenditure and body weight

Area of Science:

• Human physiology
• Obesity research
• Metabolic studies

Background:

• The Mayer hypothesis, proposed 50 years ago, posits an energy balance regulation threshold, beyond which sedentary individuals risk obesity.
• Testing this hypothesis in humans was historically challenging due to difficulties in accurately measuring total energy expenditure (TEE).

Purpose of the Study:

• To test the Mayer hypothesis regarding physical activity thresholds and obesity in humans.
• To investigate the relationship between total energy expenditure (TEE) relative to resting metabolic rate (RMR) and body weight regulation.

Main Methods:

• Utilized the doubly labeled water (DLW) method for accurate measurement of total energy expenditure (TEE).
• Analyzed cross-sectional data from DLW studies in adult men and women.
• Conducted a longitudinal study on previously obese women, including an exercise intervention.

Main Results:

• Cross-sectional data supported the Mayer hypothesis in men, linking higher TEE ( > 1.75x RMR) to lower body mass index.
• Longitudinal data in women showed that TEE:RMR ratios above 1.75 were associated with less weight gain.
• An exercise program increasing TEE:RMR to 1.75 halted weight gain in previously obese women, which resumed upon program cessation.

Conclusions:

• The doubly labeled water method enables quantitative testing of the Mayer hypothesis.
• Findings generally support the Mayer hypothesis, indicating a physical activity threshold that helps prevent weight gain and obesity.