Reduced-fat breakfast impact on appetite regulation in healthy adults: Views from a nutritional and psychological pilot study

The study aimed to assess the impact of modulating fat content in breakfast on psychological and physiological mechanisms of appetite and energy intake. In a crossover design, 8 young healthy adults consumed a standard-breakfast (SB, 505 Kcal) or the same breakfast with 61.6% reduced-fat (RF, 381 Kcal). Glucose, insulin and glucagon-like peptide 1 (GLP-1) concentrations were collected before and after breakfast at regular intervals up to 90 min (120 min for glucose). Appetite related feelings were noted in visual analogue scales before and after breakfast at regular intervals until lunch. Participants logged food intake for the rest of the day. Physiological responses were significantly different over time: glucose peaked at 15 min, insulin and GLP-1 at 30 min. Yet breakfast type did not influence these responses. Despite no impact in GLP-1, fullness-90 min post-breakfast was higher in SB than RF, p<0.05. Breakfast type did not influence energy day intake. However, lunch-protein and carbohydrate intakes were higher in RF than SB days, p<0.05. This possible energy compensation, along with decreased fullness between breakfast and lunch, deserve further research as it may challenge current low-fat recommendations for weight loss.