Weight gain in adulthood is reportedly not caused by a metabolic slowdown, as total daily energy expenditure and basal metabolic rate remain stable throughout adulthood.

noli's read

This claim is based on a major study published in the journal Science (2021) by Pontzer et al., which analyzed the energy expenditure of more than 6,400 individuals. The researchers effectively identified four phases of metabolic life, showing that the basal metabolic rate remains remarkably stable between the ages of 20 and 60, contradicting the common belief in an inevitable slowdown. What is true is that changes in body composition (loss of muscle mass) and lifestyle adjustments influence weight gain more than metabolism itself. The term "avoidable" is, however, an optimistic interpretation: while metabolism does not drop, environmental factors, progressive sedentary behavior, and hormonal changes play a complex role that this study alone cannot fully obscure. It is therefore solid evidence (a large-scale observational study using the doubly labeled water method) that helps reframe the debate regarding metabolic responsibility.

the sources

No named source held this one up — that absence is part of the verdict.