Get access to everything we publish when you sign up for Outside+.
For more by Dr. Jonny Bowden check out Weighty Measures.
Q: I’ve heard that some companies offer genetic testing for custom diets. Can this be useful?
A number of companies have sprung up recently offering relatively inexpensive DNA testing to help you find the diet that’s right for you based on your genes.
The overarching principle that people are different, metabolically, hormonally, and genetically is of course 100 percent correct, and it certainly stands to reason that individual differences account for a big part of why some people, not all, thrive on Atkins, some people do fine as vegetarians and others find Snooki and Justin Bieber endlessly fascinating.
The problem is that these companies test for only a handful of genes out of approximately some 30,000 possibilities. It is very rare that a single gene determines anything by itself; genes work in combination and in conjunction with environmental forces that turn them “on” or “off.” Who’s to say that testing for a chosen few genes will tell you anything you wouldn’t figure out by filling out a good questionnaire or simply paying attention to how you feel after you eat certain foods?
In my opinion, genetic testing has a lot of potential, but when it comes to determining your ideal diet, it’s just not ready for prime time.