Adaptive thermogenesis after moderate weight loss: magnitude and methodological issues

Area of Science:

• Metabolic research
• Human physiology
• Obesity research

Background:

• Adaptive thermogenesis (AT) is the body's adjustment of energy expenditure in response to changes in energy intake.
• Understanding AT is crucial for managing weight loss and preventing obesity.
• Current methods for assessing AT vary, potentially leading to inconsistent results.

Purpose of the Study:

• To evaluate adaptive thermogenesis (AT) using 13 distinct mathematical methods.
• To compare the results obtained from different AT assessment approaches.
• To determine if AT occurs following moderate weight loss (WL).

Main Methods:

• Ninety-four participants with obesity (BMI 31.1 kg/m²) underwent a 1-year lifestyle intervention.
• Participants were randomized into an intervention (IG) or control group (CG).
• Measurements of fat mass, fat-free mass, and resting energy expenditure (REE) were taken at baseline and 4 months, with AT assessed via 13 methods.

Main Results:

• The intervention group achieved a mean weight loss of 4.8% and fat mass loss of 11.3%.
• Adaptive thermogenesis (AT) was observed in the intervention group across all assessment methods, ranging from -65 to -230 kcal/day.
• Three methods indicated significant AT in the control group.

Conclusions:

• Adaptive thermogenesis (AT) consistently occurred after moderate weight loss (WL) irrespective of the assessment methodology.
• The study highlights the need for standardized methods in AT assessment.
• Direct comparisons between studies utilizing different AT assessment techniques should be avoided due to potential variability.