Diana A. Díaz Rizzolo
Lecturer in the Department of Health Sciences at the Open University of Catalonia (UOC), member of the NUTRALiSS Nutrition, Food, Health and Sustainability Research Group at the UOC, coordinator of the Lifestyle Working Group of the Spanish Diabetes Society
This is a powerful study that uses data from three large US cohorts, which gives it a lot of robustness. Although it is observational, it is well designed and adjusted for multiple factors, so even though it cannot prove causality due to the nature of the study, its results allow us to consider it a reasonable possibility. Why? Because it addresses a key point that many nutritional epidemiological studies tend to overlook, and this is where bias usually lies: it accurately analyses what foods are consumed when French fries are not consumed.
This is key, because in nutrition it is not only what we eat that matters, but also what we stop eating when we do so. The replacement food can completely change the impact of a dietary decision, and this overall dietary pattern often has a greater impact on overall health than the contribution of a specific food.
Yes, there is a 20% increase in relative (not absolute) risk when eating chips, but this is not observed for other types of cooking, reinforcing the idea that we should not demonise whole foods without considering how they are prepared, what they are accompanied by or what they are replaced with. In fact, the study shows that replacing them with whole grains can be beneficial, while replacing them with white rice can be even worse for our glycaemic profile, which is actually quite in line with current guidelines.