Abstract / Summary
Purpose: Disrupted satiety signalling has been proposed as a possible mechanism driving high energy intakes associated with the consumption of ultra-processed foods (UPFs). We examined whether transitioning from a diet low in UPFs to a high-UPF diet affects satiety responsiveness.
Methods: In a randomized crossover trial, participants (n = 32; mean ± SD: age 27 ± 2 y; BMI 23.6 ± 2.3 kg/m2) with habitual low-UPF intakes completed two 14-day UPF diets (~ 95%EN from UPFs), separated by a 14-day washout period. Acute satiety responsiveness was assessed using a mixed-meal tolerance test with a fixed-calorie load at baseline and following each 14-day diet. Subjective appetite ratings and plasma concentrations of glucagon-like peptide-1 (GLP-1), ghrelin, pancreatic polypeptide (PP), and peptide YY (PYY) were measured from 10 min prior to 180 min following the fixed-calorie load. Satiety responsiveness was also assessed over-time within each UPF diet-arm, through daily fasting-state appetite ratings prior to breakfast.
Results: A small but significant difference was observed in acute subjective satiety ratings for total area under the curves (AUCs), with higher hunger and lower fullness AUCs following the high-UPF diets compared with baseline-measurements, though no significant differences were observed at individual timepoints (all, p > 0.05). Satiety hormone responses to the fixed-calorie load did not differ between baseline and following 14-day high-UPF exposure (all, p > 0.05). Within each diet period, fasting-state appetite ratings remained stable across days on both UPF diets.
Conclusion: Our results do not support the hypothesis that satiety responsiveness is disrupted following two 14-day periods of high-UPF diet exposure. The study was pre-registered at clinicaltrials.gov (NCT06113146).