For 33 years of my life, between 1977 and 2010, I was a major advocate of the idea that all athletes must eat high carbohydrate diets before, during and after exercise. I promoted this concept particularly strongly in my book Lore of Running.
Then, somewhat unexpectedly, I had a moment of epiphany. After reading Westman, Phinney and Volek’s book, The New Atkins for a New You, I decided to adopt the polar opposite of that diet and to restrict my carbohydrate intake to 25-50g per day by eating a high (70%) fat diet.
Subsequently I discovered that I had also developed Type 2 Diabetes Mellitus (T2DM) (on the basis of a strong genetic history and a 33‐year long diet high in carbohydrates).
In this lecture I will contrast the metabolic effects of high carbohydrate and high fat diets during exercise and pose the question: Might a high carbohydrate diet for athletes increase their risk for T2DM if they are insulin resistant?