The Study
Acute exposure to long-chain fatty acids impairs α2-adrenergic receptor-mediated antilipolysis in human adipose tissue Published, JLR Papers in Press, July 11, 2007.
This study found that when people eat a lot of fat and then exercise, their body stops slowing down fat breakdown as much as usual. But it doesn't prove that the fat caused this — it just shows they happened together.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Your fat cells have a brake (alpha-2 receptors) that stops fat from breaking down. Eating a very fatty meal turns off that brake, so your body can burn more fat while you exercise.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 531 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — this means eating fat can help your body access stored fat for energy during workouts, even without changing hormones.
- 2After eating a 95% fat meal, fat breakdown increased during exercise.
- 3In lab tests, fatty acids at 200 μmol/L blocked the fat-braking signal in fat cells.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Journal of Lipid Research
Year
2007
Authors
J. Polák, C. Moro, D. Bessière, J. Hejnová, M. Marques, M. Bajzová, M. Lafontan, F. Crampes, M. Berlan, V. Štich
Related Content
Claims (6)
Eating a high-fat meal before exercising raises levels of free fatty acids in the blood of both lean and obese men, but does not change the levels of the stress hormones epinephrine and norepinephrine in the bloodstream.
In fasted individuals exercising, fat breakdown is more strongly suppressed in obese men than in lean men due to the activity of alpha-2-adrenergic receptors.
Eating a high-fat meal reduces the ability of certain receptors in fat tissue to slow down fat breakdown, and this happens directly in the fat tissue itself, not because of changes in stress hormones circulating in the blood.
Eating a very high-fat meal before exercising reduces the normal biological brake on fat breakdown in fat tissue under the skin, leading to more fatty acids being released into the bloodstream during physical activity.
In human fat cells grown in the lab, long-chain fatty acids at a specific concentration reduce the ability of certain receptors to block fat breakdown, which may explain how dietary fat promotes fat utilization at the cellular level.
Fat cells in the lower abdomen have more alpha-2 receptors than beta receptors, which makes them less responsive to signals that trigger fat breakdown.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.