Extended Data Fig. 2: Overview of the study design.
From: Short-term effects of high-protein, lower-carbohydrate ultra-processed foods on human energy balance
Twenty-four healthy young adults participated in a single-blind crossover trial and were randomized to receive either a high-protein, lower-carbohydrate diet (HPLC, 30 % protein, 29 % carbohydrates, CHO) or normal-protein, normal CHO diet (NPNC, 13 % protein, 46 % CHO) for 5.5 days followed by the alternate diet for 5.5 days. Washout between interventions was at least 4 days. Day 1-3 were a run-in period at home with provided foods containing <45 % ultra-processed foods (UPF), whereas days 4-6 comprised a 54-h intervention with >80 % UPF in a whole-room indirect calorimeter (WRIC) at Kiel University. During the inpatient stay, a physical activity level (PAL) of 1.45 was maintained, energy intake and energy expenditure were measured, eating rate was assessed and 24-h urine was collected. On day 5 during breakfast, postprandial blood samples were taken and subjective appetite ratings using visual analogue scales were collected. On day 6 during breakfast, gastric emptying was assessed. Continuous interstitial glucose monitoring was used during the whole study period.
