*Geek Box: Foods vs. Formulas
One issue facing nutrition is when the outcome of interest is a nutrient, for example saturated fat, or dietary sugars, is the way the nutrient or combination of nutrients is delivered. In order to be specific with the quantity of the nutrient, or to isolate it from other nutrients, many controlled feeding studies have often used formulas.
Interestingly, however, the altered digestibility of formulas does have implications for the findings. For example, in a comprehensive meta-analysis of 395 metabolic ward feeding studies looking at the different effects of dietary fat and carbohydrate on blood cholesterol levels, there was a difference in effect evident between studies which used liquid formulas compared to solids.
In addition, people in the real world don’t consume formulas, they consume foods, and by focusing on food as the exposure of interest, it is the composite of the entire food matrix that will have effect, thus being more relevant to people’s exposures in the real world.
The past decade or so has seen a dramatic paradigm shift in nutrition-science toward food-based interventions, which are inherently more relevant for the wider population. Of course, if you haven’t checked out our video lecture and long-form article on ‘Moving to a Food-Based Paradigm’, please do!