Rapid responses are electronic letters to the editor. They enable our users to debate issues raised in articles published on thebmj.com. Although a selection of rapid responses will be included online and in print as readers' letters, their first appearance online means that they are published articles. If you need the url (web address) of an individual response, perhaps for citation purposes, simply click on the response headline and copy the url from the browser window. Letters are indexed in PubMed.
The authors are to be congratulated on their thorough and wide-ranging exposé of the various efforts to integrate genomic information into nutrition decisions. The only significant disagreement relates to their view that genetic information is fundamentally different from other types of information and that this entire category has to somehow be developed and regulated further before it can become practically useful. This tendency to lump use of any genetic information in nutrition is neither defensible in principle nor in specific instances. The incorporation of each genetic variant or pattern into nutritional decision making stands on its own. While much can be learned from experiences with other genetic variants, nothing dictates that all of them have to move forward in lockstep and be judged jointly. An illustration of this inappropriate grouping is the widely voiced comment on the recent findings that the use of genetic variants is not useful because three particular polymorphisms did not predict response to a weight-loss intervention (Gardner et al., 2018). Nobody would seriously consider to apply a similar standard and declare that in the absence of demonstrated effects of a particular sleep pattern on vitamin C status, neither smoking nor other lifestyle factors should be considered for deciding on dietary needs. We have to recognize that genetic variants are firmly established as important landmarks to navigate our nutrition landscape and that each has to be considered on its own merit.
Gardner CD, Trepanowski JF, Gobbo LC, et al. Effect of Low-Fat vs Low-Carbohydrate Diet on 12-Month Weight Loss in Overweight Adults and the Association With Genotype Pattern or Insulin Secretion. The DIETFITS Randomized Clinical Trial. JAMA 2018;319(7):667-679
No competing interests
14 June 2018
Physician and Professor of Nutrition
University of North Carolina at Chapel Hill, UNC Nutrition Research Institute
UNC Nutrition Research Institute, Human Research Core and Nutrigenetics Laboratory, 500 Laureate Way, Kannapolis, NC 28081