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(OR05-01-26) Why “Eat Fewer Ultra-Processed Foods” Is Challenging: Evidence for Transient Devaluation of Minimally Processed Food in Humans

Saturday, July 25, 2026
10:00 AM - 10:12 AM ET
Location: Maryland Ballroom C

    Presenting Author(s)

  • Diana G. Hume Rivera, BA (she/her/hers)

    Intramural Research Training Awardee Research Fellow
    National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health
    Bethesda, Maryland, United States

    Disclosure(s): No relevant financial relationship(s) with ineligible companies to disclose.

    • Co-Author(s)

  • Valerie L. Darcey, PhD, MS, RD, LD (she/her/hers)

    Stadtman Investigator
    National Institutes of Health, NIDDK
    Bethesda, Maryland, United States

  • KH

    Kevin D. Hall

    National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, United States

  • MK

    Michale J. Krashes

    National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, United States

  • JG

    Juen Guo, MS, PhD

    National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Maryland, United States

Disclosure(s):
Diana G. Hume Rivera, BA: No relevant financial relationship(s) with ineligible companies to disclose.
Valerie L. Darcey, PhD, MS, RD, LD: No relevant financial relationship(s) with ineligible companies to disclose.
Objectives: Prevailing public health messages urge us to reduce consumption of ultra-processed foods (UPFs) yet many report difficulties in cutting down intake. Preclinical data show high-fat diet exposure decreases the motivational value (devaluation) of nutritionally balanced chow via reward-circuit adaptations. We explored whether exposure to a diet high in UPF causes devaluation of MPF in humans.

Methods: In two inpatient randomized crossover feeding studies, weight-stable adults (Study 1: n=20 (10F,10M), age 31.2 ± 1.6 years and BMI 27 ± 1.5 kg/m2; Study 2: n=18 (7F, 11M), age 38.4 ± 2.6 years and BMI 28.7 ± 1.4 kg/m2) consumed >7 days of ad libitum UPF followed by nutrient- and duration-matched ad libitum MPF diets, or the reverse. Energy intake (EI) was expressed relative to estimated energy needs (resting expenditure via indirect calorimetry*1.6). Daily EI was compared across diet transitions (UPF-to-MPF; MPF-to-UPF) using paired t-tests (α=0.05).

Results: Mean weekly UPF EI exceeded energy needs (Study 1: +20.4%±5.9%, p=0.003; Study 2: +31.7%±11.5%, p=0.025), whereas mean weekly MPF EI approximated energy needs (Study 1: +0.13%±4.7%; Study 2: −5.3%±10.4%; p’s >0.05). Analysis of daily EI, however, revealed a transient spontaneous decrease in ad libitum MPF EI following UPF-to-MPF switch reflecting a marked reduction in intake relative to both the end of UPF diet; (Study 1: −18.1%, p=0.002; Study 2: −12%, p=0.014) and energy balance (Study 1: -6.3%±0.06%[SE], 95%CI 6.4%-19.2%; p< 0.001; Study 2: -19.0%±11.4%[SE], 95%CI 7.2% - 54.7%; p< 0.001). No such effect occurred following MPF-to-UPF transitions.

Conclusions: Exposure to a diet high in UPF produced a transient reduction in ad libitum MPF EI intake, consistent with dynamic recalibration of food value. Diets high in UPFs may increase subjective incentive value of food relative to MPF, potentially contributing to the difficulty of sustaining dietary change in free-living conditions where food options are unconstrained.

Funding Sources: This research was supported by the Intramural Research Program of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) within the National Institutes of Health (NIH). The contributions of the NIH author(s) are considered Works of the United States Government.