What happens to athletes' bodies when they eat more fat and less carb for a week?
Effects of fat adaptation and carbohydrate restoration on prolonged endurance exercise.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Fat oxidation remained elevated even after carbohydrate restoration.
Most assume that once you eat carbs again, your body switches back to burning carbs — but here, the metabolic shift from fat adaptation persisted despite high carb availability.
Practical Takeaways
Endurance athletes can increase fat burning during long, steady efforts by following a short-term high-fat, low-carb diet.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Fat oxidation remained elevated even after carbohydrate restoration.
Most assume that once you eat carbs again, your body switches back to burning carbs — but here, the metabolic shift from fat adaptation persisted despite high carb availability.
Practical Takeaways
Endurance athletes can increase fat burning during long, steady efforts by following a short-term high-fat, low-carb diet.
Publication
Journal
Journal of applied physiology
Year
2001
Authors
A. Carey, H. Staudacher, N. Cummings, Nigel K. Stepto, V. Nikolopoulos, Louise M. Burke, John A. Hawley
Related Content
Claims (5)
When your body gets used to burning fat for fuel, it becomes better at using fat by turning up the systems that break it down and use it for energy.
For endurance athletes, switching to a high-fat diet for six days and then loading up on carbs doesn’t seem to boost performance in a one-hour cycling test compared to sticking with a high-carb diet.
If endurance athletes eat a high-fat, low-carb diet for just 6 days, their bodies burn way more fat during a long bike ride — about 50 grams more over 4 hours — compared to when they eat lots of carbs, even if they're used to carb-heavy diets.
When endurance athletes eat a high-fat diet for 6 days, their bodies burn less carbs during a long bike ride compared to when they eat a high-carb diet — showing their metabolism switches to using more fat for fuel.
Even after endurance athletes eat lots of carbs for a day, their bodies still burn more fat than usual if they recently spent a week on a high-fat diet.