Seeds for the CIAT Genebank

The Hype and Hope of Personalized Nutrition

At YWM2017 yesterday, Christopher Gardner took a hard look at the hype and hopes for personalized nutrition. It’s an area of intense scientific interest. But a lot of sciency-sounding personalized nutrition advice is more sizzle than substance, as Gardner explained.

If someone wants to sell you high-priced genetic testing to reveal the perfect diet for you, think twice before you bite.

Average Results Hide the Fact That Everyone Is Different

For years now at Stanford, Gardner has been studying how different people respond very differently to different diets. In 2007, he published research in JAMA that showed people could lose weight quite successfully with a high-fat, low-carb diet.

With data from that study and others, Gardner pointed out the tremendous range of individual responses to different diets. On a given diet, some people might lose 50 pounds or more. Others might actually gain 10-15 pounds. Surely variations in biology can explain these difference.

So experts have come to accept that no one dietary prescription can fit the needs for everyone. Many people, for example, find they can’t stick with an Atkins-style diet over the long term. The question has shifted from what’s the best diet, to which diet is best for whom.

Research Yields More Clues than Answers

In his latest research, Gardner says he’s found more clues than definitive answers. So far, genes don’t really explain who’s going to respond. Insulin resistance doesn’t either. He has hopes that he might find clues from intestinal microbes taken from stool samples.

Other researchers have found a few clues. Data from the POUNDS LOST study point to genetic profiles that might affect how someone responds to dietary carbs. Recent findings from the DiOGenes study suggest that glucose levels might identify people who will respond especially well to a low glycemic index diet.

But at the end of the day, Gardner recommends paying attention to a few characteristics that many healthy diets share. Just about all of them recommend more vegetables, less added sugar, and less white wheat flour. Beyond that, finding a healthy diet that works for you involves a bit of trial and error. And if you’re really serious about it, a good dietitian can help.

For more perspective, click here and here.

Seeds for the CIAT Genebank, photograph © CIAT / flickr

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July 18, 2017