Sure, when you adjust for size and age…
After rapid acceleration in total and basal expenditure during the first year, adjusted expenditures progressively decline thereafter, reaching adult levels at ~20 years of age. Elevated adjusted expenditures in this life stage may reflect the metabolic demands of growth and development. Adult expenditures, adjusted for body size and composition, are remarkably stable, even during pregnancy and postpartum. Declining metabolic rates in older adults could increase the risk of weight gain. However, neither fat mass nor percentage increased in this period (fig. S3), which is consistent with the hypothesis that energy intake is coupled to expenditure (24).
There’s a wall in your 20s when your body is done growing.
Which coincidentally is when people start gaining weight and complaining about their metabolism
If you’re not growing and taking in the same amount of calories, they’re going to be stored as fat.
Sure.