The Influence of Ultraprocessed Food Consumption on Energy Intake in Emerging Adulthood: A Controlled Feeding Trial.

Abstract

This study examined the impact of a 2-week eucaloric diet high in ultraprocessed foods (UPF) compared to a diet without UPF (non-UPF) on ad libitum energy intake (EI) and food selection in individuals aged 18-25. In a randomized, crossover, proof-of-concept trial, participants completed two 14-day controlled feeding periods (81% UPF vs. 0% UPF), with a 4-week washout. Diets were matched for macronutrients, fiber, added sugar, diet quality, and energy density. Following each condition, participants consumed an ad libitum buffet meal including UPF and non-UPF. Energy and food grams consumed were quantified. Statistical analyses were conducted for the full sample, late adolescents (aged 18-21), and young adults (aged 22-25). Twenty-seven individuals aged 22 ± 2 years (mean BMI = 24 ± 3 kg/m²) were included. Diet compliance was ~99% overall. There was no effect of diet condition on meal total kcal or grams consumed or UPF or non-UPF consumption in the full sample (all p > 0.05). In the exploratory age subgroup analysis, an interaction between diet and age was observed for total EI (p < 0.001), where total EI increased among adolescents following the UPF diet (p = 0.03, d = 0.79), but not in young adults. Late adolescents may be susceptible to increased EI following a UPF diet. Future trials are warranted to evaluate this possibility. ClinicalTrials.gov: NCT05550818.