We’re all a little different in terms of physiology. That’s why some people have an easier time building muscle and losing fat compared to others. In addition to these individual differences, what we eat can have an impact on the maximal rate of fat oxidation during exercise. Consider the findings of a study published in the American Journal of Clinical Nutrition.
Researchers used indirect calorimetry to determine the maximal fat oxidation rates of 305 healthy adult subjects. The average maximal rate of fat oxidation was 0.55 grams per minute. After analyzing dietary intake in the 4 days leading up to testing, they found carbohydrate consumption had a negative association with fat oxidation and fat consumption had a positive association. The variability was around 2.6%.