In overweight and obese adults who are inactive, burning 3,000 kilocalories per week through aerobic exercise for 12 weeks leads to measurable decreases in body fat, but burning 1,500 kilocalories...
Mechanism
Synthesis from 1 study
When you exercise a lot, your body makes you feel hungrier and less full by changing certain hormones. This makes you eat more, which cancels out some of the calories you burned. But if you exercise enough, your body can't fully make up for all the calories you used, so you still lose fat. At lower...
Most probable mechanism
When you exercise a lot, your body senses you're burning more energy and responds by changing hormones that control hunger and fullness. This makes you feel hungrier and less satisfied after eating, so you end up eating more without realizing it — which cancels out the calories you burned. But if you exercise enough, your body can't fully compensate, and you still lose fat.
Aerobic exercise increases energy expenditure, creating a transient energy deficit
The energy deficit stimulates increased secretion of acylated ghrelin from gastric cells, enhancing hunger signals
The energy deficit reduces secretion of glucagon-like peptide-1 from intestinal cells, weakening satiety signals
Elevated acylated ghrelin and reduced glucagon-like peptide-1 act on hypothalamic appetite centers to increase perceived hunger and reduce feelings of fullness
Increased hunger and reduced satiety lead to elevated energy intake, partially offsetting the exercise-induced energy deficit
At 1,500 kcal/wk energy expenditure, compensation fully offsets the deficit, preventing fat loss; at 3,000 kcal/wk, compensation is incomplete (33.6% vs. 62.9%), allowing net fat loss
Less supported by current evidence, but not ruled out
Exercise might make food seem more rewarding or tempting, causing people to eat more without feeling hungrier — but this effect was unexpectedly reduced in the study, making it unlikely to be the main driver.
Aerobic exercise creates an energy deficit, which in some contexts increases the motivational value of food via dopamine reward pathways
Increased food reinforcement enhances food-seeking behavior and consumption, contributing to energy intake compensation
In this study, food reinforcement decreased after training, contradicting the expected direction and suggesting it is not the dominant compensatory mechanism
Evidence from Studies
Supporting (1)
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Energy compensation in response to aerobic exercise training in overweight adults.
Contradicting (0)
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