Research

Energy balance

Total daily energy expenditure (TDEE) declines significantly with age in both males and females, primarily driven by reductions in fat-free mass and increases in fat mass, with the most substantial drop occurring during the transition from middle age to older adulthood.

Your daily calorie needs drop as you age, especially after 55. This isn't just 'hormones'; it's largely because you lose muscle (fat-free mass) and gain fat. To maintain your weight, you must adjust your caloric intake or increase activity to match this lower expenditure. Focus on preserving muscle mass through resistance training to keep your metabolic rate higher.

GoodSupportsHIGH confidence
These results suggest that age influences changes in body composition and energy expenditure similarly between males and females. The most significant change in TDEE occurs as individuals transition from middle age to older adulthood.
Hannah E. Cabre et al. · Current Developments in Nutrition · 2025

Why this rating

Large sample size (N=2326) and use of the gold-standard Doubly Labeled Water (DLW) method, though cross-sectional design limits causal inference.

Source

Sex Differences in Measures of Energy Expenditure and Body Composition in Young, Middle-Aged, and Older Adults

Hannah E. Cabre et al. · Current Developments in Nutrition · 2025

DOI 10.1016/j.cdnut.2025.107614

cross_sectional · n=2326
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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