Carbohydrate-Rich Diets Result In Better Performance And Body Composition Measures Than Ketogenic Diets

A large review of 18 controlled trials, pitting ketogenic diets against carbohydrate-rich diets in athletes and well-trained adults, has shown that carb-rich diets result in significantly improved outcomes - not only in time trial performance, but also in one-rep max lifts and body composition measures.

The meta-analysis, published in Critical Reviews in Food Science and Nutrition, combined the results from all 18 peer-reviewed studies, and found that carb-rich diets, on average, resulted in 3.3% improvements in time-trials, 5.7% improvements in one-rep max performance, and 0.8kg greater increases in fat-free mass (such as muscle and bone mass).

While the ketogenic diets led to greater average total weight loss, this came at the expense of failing to gain as much muscle mass as the carb-rich group, as well as the inferior performances in both cycling time trials and maximum strength tests. The authors concluded that ketogenic diets were “not suitable for enhancing strength 1-RM or high-intensity cyclic performances” and that “a small negative effect on fat-free mass was observed”.

On the other hand, carbohydrates, which come almost exclusively from plant foods such as legumes, grains, fruits and starchy vegetables, have been shown to be the optimal fuel source for endurance and strength exercise. Since the plant foods these carbohydrates come packaged within are loaded with many other important nutrients - including fiber, healthy fats, vitamins, minerals, antioxidants and phytochemicals - a diet centered around them can aid performance and recovery in several other ways too.

References:

Koerich, A. C. C., Borszcz, F. K., Thives Mello, A., de Lucas, R. D., & Hansen, F. (2022). Effects of the ketogenic diet on performance and body composition in athletes and trained adults: a systematic review and Bayesian multivariate multilevel meta-analysis and meta-regression. Critical reviews in food science and nutrition, 1–26. Advance online publication. https://doi.org/10.1080/10408398.2022.2090894

Shaw, K. A., Zello, G. A., Rodgers, C. D., Warkentin, T. D., Baerwald, A. R., & Chilibeck, P. D. (2022). Benefits of a plant-based diet and considerations for the athlete. European journal of applied physiology, 122(5), 1163–1178. https://doi.org/10.1007/s00421-022-04902-w