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Introduction
Nutrition science plays a pivotal role in shaping public health advice, but the influence of industry funding on research has become a pressing concern. In this episode we want to examine whether we can trust nutrition studies funded by food and beverage companies, and how you can discern study credibility.
The discussion is highly relevant in today’s landscape, where conflicts of interest and bias in research are under scrutiny amidst debates on sugar, processed foods, and diet recommendations. By exploring how industry sponsorship might skew results or interpretations, this episode speaks to broader issues of scientific trustworthiness and evidence-based policy in nutrition and public health.
In this episode, we take a look at some recent publications that showed how study results and reporting differed significantly depending on if industry had funded the study or not. We delve into how this happens. As most often it is not a case of data fabrication or corruption, but rather how bias leads to studies being designed and reported differently.
We walk through some examples, as well as highlighting some industry-funded studies that didn’t provide a “pro-industry” result and conclusion.
The hope is that the episode allows you to understand why this is a problem, how to spot it, and how to know if you can trust the results of an industry-funded study.
Related resources
- Join the Sigma newsletter for free
- Subscribe to Sigma Nutrition Premium
- Become a member of Alan Flanagan’s Alinea Nutrition Education Hub
- Enroll in the next cohort of our Applied Nutrition Literacy course
- Recommended episode: #472: Compared To What? – Understanding Food Substitution Analysis & Adjustment Models
- Studies mentioned:
- López-Moreno et al., Am J Clin Nutr. 2025 Jun;121(6):1246-1257
- Tobias, 2025 – You are what you don’t eat
- Mandrioli D, Kearns CE, Bero LA (2016) PLOS ONE 15(3): e0230469
- Schillinger et al., Ann Intern Med. 2016 Nov 1;165(12):895–897
- Schmidt et al., 2021 – The impact of diets rich in low-fat or\ full-fat dairy on glucose tolerance and its determinants: a randomized controlled trial
- Schmidt et al., 2021 – Impact of low-fat and full-fat dairy foods on fasting lipid profile and blood pressure: exploratory endpoints of a randomized controlled trial
- [00:36]Alan’s upcoming study
- [04:47]Discussion on industry funding in nutrition research
- [15:06]Case study: industry influence on red meat research
- [30:43]Case study: artificial sweeteners and industry influence
- [36:37]Case study: sugar industry’s role in research
- [38:06]Critical appraisal of industry-funded studies
- [51:58]Case study: when industry-funded study results can be trusted
- [01:01:51]Guidelines for assessing research quality
- [01:07:14]Key ideas segment (premium-only)
The Hosts
Click through to your app of choice to listen and subscribe:
Dr. Alan Flanagan has a PhD in nutrition from the University of Surrey, where his doctoral research focused on circadian rhythms, feeding, and chrononutrition.
This work was based on human intervention trials. He also has a Masters in Nutritional Medicine from the same institution.
Dr. Flanagan is a regular co-host of Sigma Nutrition Radio. He also produces written content for Sigma Nutrition, as part of his role as Research Communication Officer.
Danny Lennon has a master’s degree (MSc.) in Nutritional Sciences from University College Cork, and he is the founder of Sigma Nutrition.
Danny is currently a member of the Advisory Board of the Sports Nutrition Association, the global regulatory body responsible for the standardisation of best practice in the sports nutrition profession.
Introduction to this Episode
Nutrition science plays a pivotal role in shaping public health advice, but the influence of industry funding on research has become a pressing concern. In this episode we want to examine whether we can trust nutrition studies funded by food and beverage companies, and how you can discern study credibility.
The discussion is highly relevant in todayʼs landscape, where conflicts of interest and bias in research are under scrutiny amidst debates on sugar, processed foods, and diet recommendations. By exploring how industry sponsorship might skew results or interpretations, this episode speaks to broader issues of scientific trustworthiness and evidence-based policy in nutrition and public health.
In this episode, we take a look at some recent publications that showed how study results and reporting differed significantly depending on if industry had funded the study or not. We delve into how this happens. As most often it is not a case of data fabrication or corruption, but rather how bias leads to studies being designed and reported differently.
We walk through some examples, as well as highlighting some industry-funded studies that didnʼt provide a “pro-industry” result and conclusion.
The hope is that the episode allows you to understand why this is a problem, how to spot it, and how to know if you can trust the results of an industry-funded study.
Useful Terminology for this Episode
- Conflict of Interest (COI): A situation in which a researcherʼs personal or financial relationships (e.g. funding from a food company) may compromise or bias their objectivity. In nutrition studies, COIs often arise when authors are funded by or affiliated with food industry groups. These need to be declared in the paper.
- Funding Bias (Sponsorship Bias): The tendency for research outcomes to favor the interests of the studyʼs sponsor. For example, studies funded by a soda company might be more likely to find no harm from sugary drinks. Funding bias can manifest in study design, data interpretation, or how results are reported.
- Systematic Review: A type of research that compiles and critically evaluates all available studies on a specific question using a predefined methodology. In the context of this episode, systematic reviews (and meta-analyses) can reveal overall patterns – for instance, whether industry-funded trials consistently report different outcomes than independent trials.
- Comparator: The condition or treatment that an intervention is compared against in a study. “Compared to what?” is a critical question. Industry-funded studies sometimes choose comparators that make their product look favorable or harmless (for example, comparing sugary drinks to fruit juice rather than water, or comparing red meat to other meat rather than to plant proteins).
- Research Spin: Presenting results in a biased way that favors a desired conclusion, often by overstating positive findings or downplaying negatives. In industry-funded papers, spin can appear in how conclusions are phrased (e.g. emphasizing a foodʼs benefits or neutrality despite data indicating harm or no clear benefit). Recognizing spin is part of critically assessing if a studyʼs interpretation is trustworthy.
