Case Study: Long-Term Low-Carbohydrate, High-Fat Diet Impairs Performance and Subjective Well-Being in a World-Class Vegetarian Long-Distance Triathlete

After 32 weeks on a low-carbohydrate, high-fat diet, the athlete experienced poor performance outcomes in three professional races.

• The athlete's performance worsened, achieving his worst-ever half-Ironman placement (18th) and second worst Ironman placement (14th) after 21 and 24 weeks on the diet, respectively.
• He did not finish his third race after 32 weeks on the low-carbohydrate, high-fat diet.
• Returning to a high-carbohydrate diet resulted in a return to usual performance levels within 5 weeks, with finishes of second and fourth in two Ironman events.
• Subjective assessments revealed significant negative psychological effects while on the low-carbohydrate, high-fat diet, including feelings of depression and irritability.
• The long-term low-carbohydrate, high-fat diet did not alleviate the gastrointestinal problems the athlete had experienced.

AI simplified