OnCo
ideasIdea

Controlled feeding trials to separate ultra-processing from calories

We do not know whether ultra-processed food raises cancer risk because it makes people fat, or because of something in the food itself. Feeding volunteers matched diets for a few weeks and measuring cancer-relevant biology can tell the two apart.

The NIH inpatient trial by Hall (2019) showed people ate about 500 kcal/day more on an ultra-processed diet matched for macronutrients, supporting the adiposity route. Whether additives, emulsifiers, nitrites, sweeteners and packaging chemicals have direct effects on the gut microbiome, inflammation and DNA damage independent of energy intake is untested in humans. Controlled feeding with cancer-relevant intermediate endpoints is the only way to answer it before cohorts with 20-year follow-up mature, and it informs whether policy should target processing per se or energy density.

Hypothesis
An ultra-processed diet matched for energy, macronutrients, fibre and weight change to a minimally processed diet produces measurable adverse changes in gut microbiome diversity, faecal genotoxicity, systemic inflammation and insulin over four weeks, indicating mechanisms beyond adiposity.
Rationale
Cohorts cannot disentangle processing from energy intake; mechanistic feeding trials in humans are feasible, affordable and have precedent (Hall 2019). Results would sharpen or refute the case for UPF-specific regulation.
What would test it
Randomised crossover feeding study (n about 60) with domiciled or fully provided diets, weight-stable design, endpoints including shotgun metagenomics, faecal water genotoxicity assays, CRP, IL-6, HOMA-IR and colonic biopsy proliferation markers in a subset.
Maturity
preclinical evidence
Who has to act
research
Cost to try
Medium ($1M to $50M)
Years to first evidence
4
Bottlenecks it attacks

Connected

11top

cancers

1
Colorectal cancer

fronts

2
Diet, Exercise & LifestylePrevention & Risk

technologies

3
Dietary fibre and the gut microbiome for immunotherapy responseRed and processed meat reductionUltra-processed food and sugar-sweetened drinks

terms

3
Glycaemic index and glycaemic loadGut microbiome diversity and compositionUltra-processed food (NOVA group 4)

bottlenecks

2
Misinformation and unproven therapiesPrevention we already have is not deployed