Ingredient count is not a reliable indicator of nutritional quality: analysis across and within five processed food...

Choosing products with fewer ingredients is commonly recommended to promote healthier food choices. However, the association between ingredient count and nutritional quality is poorly documented.

To investigate the association between ingredient count and overall nutritional quality of products within five processed food categories in Québec, Canada.

In this cross-sectional study, all products from the studied food categories were purchased from food retailers.

A total of 1930 products were analyzed across five food categories (2021-2024) in Québec City: sliced breads (n=340), pasta sauces (n=347), sliced processed meats (n=487), granola bars (n = 369), and yogurts and dairy desserts (n=387).

Ingredient counts were double-coded, both manually and in R. Nutritional quality was assessed using two nutrient profiling systems: the Nutri-Score (NS) and the Canadian front-of-pack nutrition symbol (C-FOP).

Analyses were performed in R. Linear regressions were used to assess the association between ingredient count and NS, while logistic regressions were used for the C-FOP.

Using the NS, higher ingredient counts were associated with a poorer nutritional quality (higher NS) in pasta sauces (β=0.37, p <0.001), granola bars (β=0.18, p <0.001), and yogurts and dairy desserts (β= 0.08, p=0.006), with variation by subcategories for sliced breads, pasta sauces, and sliced processed meats (p<0.05). Using the C-FOP, higher ingredient counts were associated with a better nutritional quality (lower probability of displaying the C-FOP) in sliced breads (β=-0.09, p <0.001), and yogurts and dairy desserts (β=-0.07, p=0.003), but with poorer nutritional quality in pasta sauces (β=0.14, p <0.001), with variation by subcategories for granola bars, yogurts and dairy desserts with the C-FOP (p<0.05).

The association between ingredient count and nutritional quality in processed food is heterogeneous and varies between and within food categories. Hence, for foods available in Québec, it would be preferable not to recommend relying solely on ingredient count to assess the nutritional quality of foods.