Why it's hard to keep weight off after dieting
Obesity causes selective and long-lasting desensitization of AgRP neurons to dietary fat
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
When mice eat lots of fat, their brain's 'hunger neurons' stop responding properly to signals that say 'you're full' — especially from fat. Even after they lose weight, these neurons still don't listen to fullness signals from the gut, but they do respond again to seeing or smelling food.
Surprising Findings
Obese mice ate less after fasting than lean mice—even when given their favorite food.
Common belief: obese people overeat because they’re always hungry. This study shows the opposite—obesity can suppress natural hunger drives, making it harder to restart eating after fasting.
Practical Takeaways
If you’ve lost weight, prioritize protein and carbs over high-fat foods to avoid triggering your brain’s ‘fat-blind’ response.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
When mice eat lots of fat, their brain's 'hunger neurons' stop responding properly to signals that say 'you're full' — especially from fat. Even after they lose weight, these neurons still don't listen to fullness signals from the gut, but they do respond again to seeing or smelling food.
Surprising Findings
Obese mice ate less after fasting than lean mice—even when given their favorite food.
Common belief: obese people overeat because they’re always hungry. This study shows the opposite—obesity can suppress natural hunger drives, making it harder to restart eating after fasting.
Practical Takeaways
If you’ve lost weight, prioritize protein and carbs over high-fat foods to avoid triggering your brain’s ‘fat-blind’ response.
Publication
Journal
eLife
Year
2020
Authors
Lisa R. Beutler, Timothy V. Corpuz, Jamie S. Ahn, Seher Kosar, Weimin Song, Yiming Chen, Z. Knight
Related Content
Claims (8)
Masticatory activity triggers the release of cholecystokinin and suppresses ghrelin, reducing subjective hunger independent of nutrient intake.
Obese mice don't respond as well to a gut hormone (CCK) that normally tells the brain to stop eating fat—and even after they lose weight, this blunted response doesn't come back.
In obese mice, turning on hunger neurons just before eating doesn’t make them eat much more—but turning them on while they’re eating does. This suggests their brain’s feeding system becomes less sensitive to normal hunger signals.
Obese mice eat less after fasting than lean mice—even when given their favorite food—and this isn’t just because they’re heavier; it’s linked to higher levels of the fat hormone leptin.
Obese mice don’t get as excited (in brain terms) when they see food—but when they lose weight, this brain response comes back, unlike their response to fat or hormones.