Short-Term Effect of Macronutrient Composition and Glycemic Index of a Yoghurt Breakfast on Satiety and Mood in Healthy Young Men

Background: Promoting satiety and repressing appetite is one major goal in the dietetic therapy of obesity. In the past, several studies investigated the effect of different macronutrients, especially protein and carbohydrates, on short-and long-term satiety in humans. This paper aims to directly compare the effect of protein, rolled oats (low glycemic index), sugar or cornflakes (high glycemic index), and walnuts (high amount of omega-3 fatty acids) as ingredients of a yoghurt breakfast on short-term hunger and satiety in one setting. A second objective was to study the effect of these yoghurt breakfasts on mental state. Methods: 14 healthy male volunteers participated in this randomized, controlled, cross-over design study. After consuming the different test meals, volunteers repeatedly completed 2 questionnaires over a total of 3 h. Results: The protein meal showed the highest satiety scores and the controls (low-calorie yoghurt) the lowest. The other test meals were not different among each other. Regarding mental state (mood, fatigue, and calmness), no significant difference between the test meals and the low-calorie control was observed. Conclusion: The glycemic index does not seem to modify satiety in this short-term setting. The similar mental state between low-and high-calorie breakfasts deserves further investigations.