Why belly fat sticks around after dieting
Enhanced cortisol production rates, free cortisol, and 11beta-HSD-1 expression correlate with visceral fat and insulin resistance in men: effect of weight loss.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
When men lose weight, their body still makes the same amount of stress hormone (cortisol), but now it’s spread over less body fat—so the hormone becomes stronger per pound of fat left. This might trick the body into putting fat back, especially around the belly.
Surprising Findings
Cortisol levels didn’t drop after weight loss—even though fat mass decreased significantly.
Common belief: losing weight reduces stress hormones. This study shows cortisol production is stubbornly unchanged, making it harder to maintain weight loss.
Practical Takeaways
If you’ve lost weight and are struggling to keep it off, focus on stress management—not just calories. Sleep, meditation, and reducing chronic stress may help lower cortisol’s impact on fat regain.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
When men lose weight, their body still makes the same amount of stress hormone (cortisol), but now it’s spread over less body fat—so the hormone becomes stronger per pound of fat left. This might trick the body into putting fat back, especially around the belly.
Surprising Findings
Cortisol levels didn’t drop after weight loss—even though fat mass decreased significantly.
Common belief: losing weight reduces stress hormones. This study shows cortisol production is stubbornly unchanged, making it harder to maintain weight loss.
Practical Takeaways
If you’ve lost weight and are struggling to keep it off, focus on stress management—not just calories. Sleep, meditation, and reducing chronic stress may help lower cortisol’s impact on fat regain.
Publication
Journal
American journal of physiology. Endocrinology and metabolism
Year
2009
Authors
J. Purnell, Steven E. Kahn, Mary H. Samuels, D. Brandon, D. Loriaux, J. Brunzell
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Claims (5)
In men, having more of a certain gene (11β-HSD-1) active in their belly fat is linked to carrying more overall body fat, more fat around the organs, and worse blood sugar control—but it’s not just about belly fat, it’s tied to fat everywhere.
When obese men lose weight, a specific gene in their fat cells called 11β-HSD-1 becomes less active — and this seems to happen because they’re losing fat, not because the gene caused them to gain weight in the first place.
In older men, having more of the stress hormone cortisol floating around in the blood is linked to more belly fat and worse blood sugar control—even if they’re not overweight overall—suggesting stress might be quietly hurting their metabolism.
When obese men lose weight by dieting, their body doesn’t make less cortisol overall—but because they still have some fat left, the cortisol they do have is now more concentrated relative to that fat, which might trick their body into putting fat back on, especially around the belly.
Men with a lot of belly fat tend to have higher stress hormone levels during the day, but their nighttime levels stay normal—like their body’s stress clock is out of sync.