“Metabolic Response to Experimental Overfeeding in Lean and Overweight Healthy Volunteers”, Erik O. Diaz, Andrew M. Prentice, Gail R. Goldberg, Peter R. Murgatroyd, W. Andrew Coward1992 (exercise)⁠:

Possible adaptive mechanisms that may defend against weight gain during periods of excessive energy intake were investigated by:

overfeeding 6 lean and 3 overweight young men by 50% above baseline requirements with a mixed diet for 42 d [6.2 ± 1.9 MJ/d (x̄ ± SD), or a total of 265 ± 45 MJ]. Mean weight gain was 7.6 ± 1.6 kg (58 ± 18% fat). The energy cost of tissue deposition (28.7 ± 4.4 MJ/kg) matched the theoretical cost (26.0 MJ/kg).

Basal metabolic rate (BMR) increased by 0.9 ± 0.4 MJ/d and daily energy expenditure assessed by whole-body calorimetry (CAL EE) increased by 1.8 ± 0.5 MJ/d. Total free-living energy expenditure (TEE) measured by doubly labeled water increased by 1.4 ± 2.0 MJ/d. Activity and thermogenesis (computed as CAL EE − BMR, and TEE − BMR) increased by only 0.9 ± 0.4, and 0.9 ± 2.1 MJ/d, respectively.

All outcomes were consistent with theoretical changes due to the increased fat-free mass, body weight, and energy intake. There was no evidence of any active energy-dissipating mechanisms.

[Keywords: adaptive thermogenesis, overfeeding, body weight, obesity, energy expenditure, whole-body calorimetry, doubly labeled water, set-point regulation]