Commercial use of evidence in public health policy: a critical assessment of food industry submissions to global-level consultations on non-communicable disease prevention

BACKGROUND

Ultra-processed food industry (UPFI) actors have consistently opposed statutory regulation in health policy debates, including at the WHO. They do so most commonly with claims that regulatory policies do not work, will have negative consequences or that alternatives such as self-regulation work well or better. Underlying this are often assertions that industry is aligned with principles of evidence-based policymaking. In this study, we interrogate if this holds true by exploring the extent and quality of the evidence UPFI respondents employed to support claims around regulatory policy, and how they did this.

METHODS

First, we identified all submissions from organisations who overtly represent UPFI companies to consultations held by the WHO on non-communicable disease policy between 2016 and 2018. Second, we extracted all relevant factual claims made in these submissions and noted if any evidence was referenced in support. Third, we assessed the quality of evidence using independence from UPFI, nature, and publication route as indicators. Lastly, where peer-reviewed research was cited, we examined if the claims made could be justified by the source cited.

RESULTS

Across 26 included consultation responses, factual claims around regulation were made in 18, although only 10 referenced any evidence at all. Of all 114 claims made, 39 pieces of identifiable evidence were cited in support of 56 claims. Of the 39 distinct pieces of evidence, two-thirds were industry-funded or industry-linked, with only 16 externally peer-reviewed. Over half of industry-funded or industry-linked academic articles failed to declare a conflict of interest (COI). Overall, of only six claims which drew on peer-reviewed and independent research, none appropriately represented the source.

DISCUSSION

UPFI respondents made far-reaching claims which were rarely supported by high-quality, independent evidence. This indicates that there may be few, if any, benefits from consulting actors with such a clear COI.

A Whole Food Plant-Based Diet Is Effective for Weight Loss: The Evidence

What does the best available balance of scientific evidence show is the optimum way to lose weight? Calorie density, water content, protein source, and other components significantly influence the effectiveness of different dietary regimes for weight loss. By "walling off your calories," preferentially deriving your macronutrients from structurally intact plant foods, some calories remain trapped within indigestible cell walls, which then blunts the glycemic impact, activates the ileal brake, and delivers prebiotics to the gut microbiome. This may help explain why the current evidence indicates that a whole food, plant-based diet achieves greater weight loss compared with other dietary interventions that do not restrict calories or mandate exercise. So, the most effective diet for weight loss appears to be the only diet shown to reverse heart disease in the majority of patients. Plant-based diets have also been found to help treat, arrest, and reverse other leading chronic diseases such as type 2 diabetes and hypertension, whereas low-carbohydrate diets have been found to impair artery function and worsen heart disease, the leading killer of men and women in the United States. A diet centered on whole plant foods appears to be a safe, simple, sustainable solution to the obesity epidemic.

Determining the contribution of a high-fructose corn syrup formulation to hepatic glycogen synthesis during ad-libitum feeding in mice

Excessive sugar intake including high-fructose corn syrup (HFCS) is implicated in the rise of obesity, insulin resistance and non-alcoholic fatty liver disease. Liver glycogen synthesis is influenced by both fructose and insulin signaling. Therefore, the effect of HFCS on hepatic glycogenesis was evaluated in mice feeding ad-libitum. Using deuterated water: the fraction of glycogen derived from triose-P sources, Krebs cycle substrates, and direct pathway + cycling, was measured in 9 normal-chow fed mice (NC) and 12 mice fed normal chow plus a 55% fructose/45% glucose mix in the drinking water at 30% w/v (HFCS-55). This was enriched with [U-¹³C]fructose or [U-¹³C]glucose to determine the contribution of each to glycogenesis. For NC, direct pathway + cycling, Krebs cycle, and triose-P sources accounted for 66 ± 0.7%, 23 ± 0.8% and 11 ± 0.4% of glycogen synthesis, respectively. HFCS-55 mice had similar direct pathway + cycling (64 ± 1%) but lower Krebs cycle (12 ± 1%, p < 0.001) and higher triose-P contributions (24 ± 1%, p < 0.001). HFCS-55-fructose contributed 17 ± 1% via triose-P and 2 ± 0% via Krebs cycle. HFCS-55-glucose contributed 16 ± 3% via direct pathway and 1 ± 0% via Krebs cycle. In conclusion, HFCS-55 supplementation resulted in similar hepatic glycogen deposition rates. Indirect pathway contributions shifted from Krebs cycle to Triose-P sources reflecting HFCS-55-fructose utilization, while HFCS-55-glucose was incorporated almost exclusively by the direct pathway.

Association of dietary macronutrient composition and non-alcoholic fatty liver disease in an ageing population: the Rotterdam Study

OBJECTIVE

A healthy lifestyle is the first-line treatment in non-alcoholic fatty liver disease (NAFLD), but specific dietary recommendations are lacking. Therefore, we aimed to determine whether dietary macronutrient composition is associated with NAFLD.

DESIGN

Participants from the Rotterdam Study were assessed on (1) average intake of macronutrients (protein, carbohydrate, fat, fibre) using a Food Frequency Questionnaire and (2) NAFLD presence using ultrasonography, in absence of excessive alcohol, steatogenic drugs and viral hepatitis. Macronutrients were analysed using the nutrient density method and ranked (Q1-Q4). Logistic regression analyses were adjusted for sociodemographic, lifestyle and metabolic covariates. Moreover, analyses were adjusted for and stratified by body mass index (BMI) (25 kg/m²). Also, substitution models were built.

RESULTS

In total, 3882 participants were included (age 70±9, 58% female). NAFLD was present in 1337 (34%) participants of whom 132 were lean and 1205 overweight. Total protein was associated with overweight NAFLD after adjustment for sociodemographic and lifestyle covariates (OR_Q4vsQ1 1.40; 95% CI 1.11 to 1.77). This association was driven by animal protein (OR_Q4vsQ1 1.54; 95% CI 1.20 to 1.98). After adjustment for metabolic covariates, only animal protein remained associated with overweight NAFLD (OR_Q4vsQ1 1.36; 95% CI 1.05 to 1.77). Monosaccharides and disaccharides were associated with lower overall NAFLD prevalence (OR_Q4vsQ1 0.66; 95% CI 0.52 to 0.83) but this effect diminished after adjustment for metabolic covariates and BMI. No consistent associations were observed for fat subtypes or fibre. There were no substitution effects.

CONCLUSION

This large population-based study shows that high animal protein intake is associated with NAFLD in overweight, predominantly aged Caucasians, independently of well-known risk factors. Contrary to previous literature, our results do not support a harmful association of monosaccharides and disaccharides with NAFLD.

Added sugars and risk factors for obesity, diabetes and heart disease

The effects of added sugars on various chronic conditions are highly controversial. Some investigators have argued that added sugars increase the risk of obesity, diabetes and cardiovascular disease. However, few randomized controlled trials are available to support these assertions. The literature is further complicated by animal studies, as well as studies which compare pure fructose to pure glucose (neither of which is consumed to any appreciable degree in the human diet) and studies where large doses of added sugars beyond normal levels of human consumption have been administered. Various scientific and public health organizations have offered disparate recommendations for upper limits of added sugar. In this article, we will review recent randomized controlled trials and prospective cohort studies. We conclude that the normal added sugars in the human diet (for example, sucrose, high-fructose corn syrup and isoglucose) when consumed within the normal range of normal human consumption or substituted isoenergetically for other carbohydrates, do not appear to cause a unique risk of obesity, diabetes or cardiovascular disease.