Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Matters Arising
  • Published:

Concerns about attributing weight change to processing in a crossover feeding trial

Nature Medicine (2026)Cite this article

Subjects

Matters Arising to this article was published on 06 January 2026

The Original Article was published on 04 August 2025

ARISING FROM S. J. Dicken et al. Nature Medicine https://doi.org/10.1038/s41591-025-03842-0 (2025)

We read with interest the randomized, 2 × 2 crossover feeding trial comparing minimally processed food (MPF) and ultra-processed food (UPF) ad libitum diets aligned with the UK Eatwell Guide1. The study reports greater percentage weight loss over 8 weeks on MPFs than UPFs (percentage weight change (Δ%WC), −1.01%, P = 0.024), with additional differences in body composition and lipids. Nevertheless, several design and analytic features substantially weaken causal attribution to ‘processing’ and constrain the policy message: treatment-dependent attrition with a pronounced order effect, hydration-sensitive body-composition estimates, likely recognizability that can alter ad libitum intake, confounding by energy density and packaging, and secondary signals that are internally inconsistent or sensitive to multiplicity.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on SpringerLink
  • Instant access to the full article PDF.

USD 39.95

Prices may be subject to local taxes which are calculated during checkout

References

  1. Dicken, S. J. et al. Ultraprocessed or minimally processed diets following healthy dietary guidelines on weight and cardiometabolic health: a randomized, crossover trial. Nat. Med. 31, 3297–3308 (2025).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  2. Kyle, U. G. et al. Bioelectrical impedance analysis—part I: review of principles and methods. Clin. Nutr. 23, 1226–1243 (2004).

    Article  PubMed  Google Scholar 

  3. Hollands, G. J. et al. Portion, package or tableware size for changing selection and consumption of food, alcohol and tobacco. Cochrane Database Syst. Rev. 2015, CD011045 (2015).

    PubMed  PubMed Central  Google Scholar 

  4. Robinson, E. et al. A systematic review and meta-analysis examining the effect of eating rate on energy intake and hunger. Am. J. Clin. Nutr. 100, 123–151 (2014).

    Article  CAS  PubMed  Google Scholar 

  5. Robinson, E. et al. Calorie reformulation: a systematic review and meta-analysis examining the effect of manipulating food energy density on daily energy intake. Int. J. Behav. Nutr. Phys. Act. 19, 48 (2022).

    Article  PubMed  PubMed Central  Google Scholar 

  6. Livingstone, M. B. E. & Black, A. E. Markers of the validity of reported energy intake. J. Nutr. 133, 895S–920S (2003).

    Article  CAS  PubMed  Google Scholar 

  7. Benjamini, Y. & Hochberg, Y. Controlling the false discovery rate: a practical and powerful approach to multiple testing. J. R. Stat. Soc. B. 57, 289–300 (1995).

    Article  Google Scholar 

  8. Demonty, I. et al. Continuous dose–response relationship of the LDL-cholesterol–lowering effect of phytosterol intake. J. Nutr. 139, 271–284 (2009).

    Article  CAS  PubMed  Google Scholar 

  9. Whitehead, A., Beck, E. J., Tosh, S. & Wolever, T. M. S. Cholesterol-lowering effects of oat β-glucan: a meta-analysis of randomized controlled trials. Am. J. Clin. Nutr. 100, 1413–1421 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. ZHT Lab Co., Ltd, Beijing, China

    Zixuan Wang & Can Peng

  2. Beijing Information Science & Technology University, Beijing, China

    Can Peng

Authors
  1. Zixuan Wang
    View author publications

    Search author on:PubMed Google Scholar

  2. Can Peng
    View author publications

    Search author on:PubMed Google Scholar

Contributions

Z.W. conceived the analysis, interpreted the data, wrote and revised the paper, and supervised the project. C.P. assisted with data checking.

Corresponding author

Correspondence to Zixuan Wang.

Ethics declarations

Competing interests

Z.W. is the CEO and C.P. is an intern at ZHT Lab Co., Ltd, an AI research firm. The company currently has no business or financial interests related to diet or nutrition. The views expressed in this article are solely those of the authors and do not represent the position of ZHT Lab Co., Ltd.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Wang, Z., Peng, C. Concerns about attributing weight change to processing in a crossover feeding trial. Nat Med (2026). https://doi.org/10.1038/s41591-025-04088-6

Download citation

  • Received:

  • Accepted:

  • Published:

  • Version of record:

  • DOI: https://doi.org/10.1038/s41591-025-04088-6

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing