The Study
Effects of overnight-fasted versus fed-state exercise on the components of energy balance and interstitial glucose across four days in healthy adults.
This study looked at two ways of exercising—before breakfast or after eating—and saw if they changed how much people ate or how their blood sugar acted over four days. It didn’t find a big difference, but it didn’t randomly assign people or hide which group they were in, so we can’t say one definitely causes a change.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Scientists had people run either before breakfast (fasted) or after eating (fed), and tracked how much they ate, moved, and how their blood sugar changed over four days.
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 537 / 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.
- 1No, it doesn't matter if you run before or after eating — your body doesn't burn more fat or change your hunger or energy use in a meaningful way.
- 2People ate the same amount of food (about 15 MJ/day), burned the same amount of energy, and had similar blood sugar levels whether they ran fasted or fed.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Appetite
Year
2024
Authors
I. Podestá D, A. Blannin, G. Wallis
Related Content
Claims (2)
When people walk in a fasted state versus a fed state but consume the same calories and burn the same amount of energy, the amount of fat lost is the same.
In healthy, active adults, exercising after fasting overnight has the same effect on daily calorie intake, energy burned, appetite, and blood glucose levels as exercising after eating, over a four-day period.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.