Consistency between the Eatwell Guide and nutrient profiling models in the UK: an observational study

Abstract

BackgroundNutrient profile models (NPMs) are algorithms that classify or rank foods according to their nutritional composition. An NPM was developed in 2005 in the UK to regulate marketing of foods to children. The model uses a scoring system that balances points awarded for the protein, fibre, fruit, vegetable, and nut content of foods and drinks against points awarded for energy, saturated fats, sodium, and sugars. Foods that score above 4 and drinks that score above 1 face marketing restrictions. The NPM was revised in 2018, but this version has not been finalised. The Eatwell Guide, the UK's food-based dietary guidelines, provides healthy eating advice. The aim of this study was to evaluate the extent that the 2005 and the 2018 versions of the NPM are consistent with the Eatwell Guide. MethodsIn this observational study, we obtained individual-level data from years 9 to 11 (2016/17 to 2018/19) of the National Diet and Nutrition Survey (NDNS). The NDNS is an annual survey measuring food consumption in the UK from a representative sample of approximately 1000 people per year. We estimated the healthiness of individuals' diets according to an Eatwell Guide dietary index (ie, number of food-based and nutrient-based recommendations achieved) and an NPM dietary index (ie, a weighted average of the NPM score of all foods eaten). We compared the agreement between diet healthiness according to the Eatwell Guide and the NPM indices by calculating the Cohen's κ coefficient. No specific ethics approval or patient consent was required for this analysis of NDNS data. Findings3028 individual diets were assessed. Individuals with a higher (ie, healthier) Eatwell Guide index score consumed a diet with, on average, a lower (ie, healthier) NPM index score both for the 2005 and 2018 versions. Agreement between the Eatwell Guide and the NPM dietary index in classifying a diet as “healthy” was moderate for relatively healthier diets, irrespective of the NPM version (Cohen's κ 0·39 [p<0·0001] for the 2005 version and 0·46 [p<0·0001] for the 2018 version, using an NPM cutoff of 4). InterpretationThis study suggests that the Eatwell Guide and NPM dietary indices are broadly concordant when assessing the healthiness of UK diets. As NPMs and food-based dietary guidelines evolve it is crucial to improve alignment between dietary advice and NPM-based food policies to ensure consistent information is conveyed to the public. FundingNIHR Academic Clinical Fellowship, Nuffield Department of Population Health (University of Oxford), NIHR Oxford Biomedical Research Centre, and the British Heart Foundation.