The Claim
In aging C57BL/6J mice subjected to 30% caloric restriction followed by ad libitum refeeding, a high-fat diet (60% kcal from fat) causes a 12.8 ± 5.7% overshoot in body weight compared to baseline, driven by an 87 ± 14% increase in energy intake, despite elevated fat oxidation and higher serum leptin levels, indicating that macronutrient composition influences weight regain primarily through energy intake rather than metabolic efficiency.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
In aging mice that lost weight through calorie restriction and then ate freely again, a high-fat diet caused them to regain more weight than they lost, primarily because they ate significantly more calories, even though their bodies burned more fat and had higher levels of the hormone leptin.
See the scientific wording
In aging C57BL/6J mice subjected to 30% caloric restriction followed by ad libitum refeeding, a high-fat diet (60% kcal from fat) leads to a 12.8 ± 5.7% overshoot in body weight compared to baseline, driven by a 87 ± 14% increase in energy intake, despite elevated fat oxidation and higher serum leptin levels, indicating that macronutrient composition influences weight regain primarily through energy intake rather than metabolic efficiency.
After weight loss, eating a high-fat diet makes the brain's reward system go into overdrive, causing the animal to eat far more food than needed. Even though the body produces more of a fullness hormone called leptin, the brain ignores it because the pleasure from fat overrides the signal. The extra calories are stored as fat, leading to weight gain beyond the original level.
What the research says
1 studyWhen older mice lose weight by eating less, then eat as much as they want again, those given a high-fat diet eat way more calories and gain back even more weight than before—even though their bodies are burning more fat and they have more of a fullness hormone. This shows it’s not about metabolism, but how much they eat.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.