Effect of Plain Versus Sugar-Sweetened Breakfast on Energy Balance and Metabolic Health: A Randomized Crossover Trial

Objective: This study investigated the effect of 3 weeks of high-sugar (“Sweet”) versus low-sugar (“Plain”) breakfast on energy balance, metabolic health, and appetite. Methods: A total of 29 healthy adults (22 women) completed this randomized crossover study. Participants had pre- and postintervention appetite, health, and body mass outcomes measured, and they recorded diet, appetite (visual analogue scales), and physical activity for 8 days during each intervention. Interventions were 3 weeks of isoenergetic Sweet (30% by weight added sugar; average 32 g of sugar) versus Plain (no added sugar; average 8 g of sugar) porridge-based breakfasts. Results: Pre- to postintervention changes in body mass were similar between Plain (Δ 0.1 kg; 95% CI: −0.3 to 0.5 kg) and Sweet (Δ 0.2 kg; 95% CI: −0.2 to 0.5 kg), as were pre- to postintervention changes for biomarkers of health (all P ≥ 0.101) and psychological appetite (all P ≥ 0.152). Energy, fat, and protein intake was not statistically different between conditions. Total carbohydrate intake was higher during Sweet (287 ± 82 g/d vs. 256 ± 73 g/d; P = 0.009), driven more by higher sugar intake at breakfast (116 ± 46 g/d vs. 88 ± 38 g/d; P < 0.001) than post-breakfast sugar intake (Sweet 84 ± 42 g/d vs. Plain 80 ± 37 g/d; P = 0.552). Participants reported reduced sweet desire immediately after Sweet but not Plain breakfasts (trial × time P < 0.001). Conclusions: Energy balance, health markers, and appetite did not respond differently to 3 weeks of high- or low-sugar breakfasts.