Do Health Benefits Or Nutrient Requirements Drive Diet Choices?
Losing weight and being fit and healthy are some of the most common resolutions American’s make at the beginning of each year. There are numerous resources that can help people achieve healthy eating goals including the media (the subject of a previous post on Talking Nutrition), MyPlate which helps individuals use the Dietary Guidelines in the US and the Food Guide in Canada. These resources are largely based around dietary intakes to help people meet their nutrient requirements. But how often do you make a dietary choice because it helps meet your nutrient requirements?
The motivation for food choices is likely similar to why people use dietary supplements; to improve or maintain overall health, or specific health benefits. This suggests a need to focus on achieving “optimal” intakes rather than just getting enough to meet requirements. A study by Jessri and L’Abbe, has put a spotlight on this issue and calls for a new Canadian food guide that provides guidance on diet for preventing chronic diseases. The author’s recommend that it is essential to model relationships between foods associated with lower risk of chronic disease (e.g. fruits and cancer, fish and heart disease) in order to develop more focused guidelines on foods to encourage.
However, the authors also made a suggestion to focus less on nutrient deficiencies when setting guidelines because “inadequate micronutrient intakes are only seen for a few nutrients”. I had to re-read that sentence to make sure I read it correctly. Diet intake is reasonably comparable between Americans and Canadians (as a Canadian living in the US and customer of both Dunkin Donuts and Tim Hortons I feel I can make that statement); the 2015 Dietary Guidelines Advisory Committee highlighted 8 shortfall nutrients for Americans. Furthermore, with the higher latitude in Canada and thus less time for vitamin D synthesis, less focus on nutrient deficiencies seems misguided. On a national level, more than one-third of Canadians had vitamin D status below optimal.
In the end, dietary guidelines based upon health outcomes may be more in line with people’s motivation for dietary choices but the role of individual micronutrients also needs to be considered.
Jessri M, L’Abbe MR. The time for an updated Canadian food guide has arrived. Appl Physiol Nutr Metab. 2015, doi:10.1139/apnm-2015-0046
Bailey RL et al. Why US adults use dietary supplements. JAMA Intern Med. 2013, doi:10.1001/jamainternmed.2013.2299