Particle size: the missing link in food regulation and nutritional labeling to combat obesity and metabolic disorders.
Consumption of highly processed foods is strongly correlated with a multitude of negative health outcomes and has been identified as a driver in obesity epidemics worldwide. The precise mechanisms for this phenomenon are not well understood, but one possibility suggests itself; in other fields it is well understood that particle size is a key parameter governing rate of reaction between solids and fluids and so, particle size, particularly of non-soluble high-glycemic nutrients such as starch, will dictate their rate of absorption and therefore the stability of blood sugar control after consuming them. Animal studies have found negative health effects associated with fine particles in feed and there is no reason not to assume the same to be present in humans. Regulations, however, have hitherto focused on macro-nutrient profiles of foods, but particle size may have independent health implications. Moreover, the presence of fine particles may not be readily apparent to consumers, particularly because many processed foods agglomerate small particles with binding agents, releasing them during digestion. Progress in the battle against metabolic disorders will require better understanding of the role of particle size, and perhaps regulations and labeling requirements.