Effects of a Carbohydrate-Restricted Diet on Affective Responses to Acute Exercise among Physically Active Participants

Currently, the carbohydrate-restricted diet is very popular. Atkins' book, Dr. Atkins' Diet Revolution, has sold millions in its more than 25 years of existence. His book promotes the carbohydrate-restricted diet, which focuses on the consumption of proteins and fats as primary calorie and energy sources, while severely restricting carbohydrates. However, when carbohydrates are restricted from the diet, the body's primary energy source is reduced considerably. Therefore, the purpose of this study was to compare the psychological responses to exercise of individuals when on a carbohydrate restrictive diet and when on a noncarbohydrate restrictive diet. For this study, 17 participants practiced a noncarbohydrate-restricted diet for three weeks and the carbohydrate-restricted diet for three weeks, while maintaining previous exercise habits. After each exercise session, the participants completed the Physical Activity Affect Scale, which measures Positive Affect, Negative Affect, Tranquility, and Fatigue. Simple one-way analyses of variance indicated significant treatment differences (ps <.05) relative to Negative Affect, Positive Affect, and Fatigue. The results of the study indicate as predicted, that, when a person restricts carbohydrates from the diet, he will experience more fatigue, more negative affect, and less positive affect in response to exercise than those individuals who are not restricting carbohydrates.