Identical net caloric deficits can result in different resting metabolic rates and hormonal profiles based on total energy flux.

Study: Caloric restriction, resting metabolic rate and cognitive performance in Non-obese adults: A post-hoc analysis from CALERIE study.

Even if two people eat the same low-calorie diet, their bodies might slow down metabolism differently — this study shows that people on calorie restriction often have different changes in resting metabolism, even when they lose the same amount of weight.

Study: One-year caloric restriction and 12-week exercise training intervention in obese adults with type 2 diabetes: emphasis on metabolic control and resting metabolic rate

Even if two people eat the same number of calories and burn the same amount, how they burn those calories — like through exercise vs. just eating less — can change their metabolism and hormones differently. This study shows that adding exercise changes your body’s energy use in ways that eating less alone doesn’t.

Study: Increasing energy flux to decrease the biological drive toward weight regain after weight loss - A proof-of-concept pilot study.

Even if two people eat and burn the same number of calories overall, the one who exercises more and eats more tends to have a higher metabolism and feel less hungry—showing that how you spend your calories matters, not just the total.

Study: Effects of increased energy intake and/or physical activity on energy expenditure in young healthy men.

Even if two people eat the same amount and burn the same calories overall, how they get there—like eating more and exercising more, or eating less and exercising more—can change how their bodies burn energy at rest. This study shows that the total amount of food and activity matters, not just the net calorie difference.