That sounds great, but I realized I had a big problem. For the most part the highly recommended foods, like cheese danishes, were ones I really disliked, while those rated C-, like oatmeal, melon and baked squash, were typically among my favorites. Bratwurst (the worst and potentially most lethal kind of food in my perception) was rated an A+! If I wanted to avoid glucose spikes, I’d have to make some pretty big sacrifices in my diet.
Nevertheless, it was an interesting first step on the path to a personalized diet. There is now a commercial version of this test, based on the research of Dr. Segal and Dr. Elinav, though it is much more limited: It only analyzes a gut microbiome sample, without monitoring glucose or what you eat.
There are other efforts underway in the field as well. In some continuing nutrition studies, smartphone photos of participants’ plates of food are being processed by deep learning, another subtype of A.I., to accurately determine what they are eating. This avoids the hassle of manually logging in the data and the use of unreliable food diaries (as long as participants remember to take the picture).
But that is a single type of data. What we really need to do is pull in multiple types of data — activity, sleep, level of stress, medications, genome, microbiome and glucose — from multiple devices, like skin patches and smartwatches. With advanced algorithms, this is eminently doable. In the next few years, you could have a virtual health coach that is deep learning about your relevant health metrics and providing you with customized dietary recommendations.
The benefits of such a coach will, of course, have to be validated by randomized trials, unlike the myriad diets that are being hawked without any proof that they are effective or even safe.
We don’t often think of a diet as being unsafe, but the wrong foods can be dangerous for people with certain risks or conditions. I’ve had two bouts of kidney stones. To avoid a third, I need to stay away from foods high in oxalate, a naturally occurring molecule abundant in plants. But if you look at the recommendations for my personalized diet, many — like nuts and strawberries — are high in oxalate. That’s a big miscue, because my pre-existing medical conditions were not one of the test’s inputs. And as we undergo significant changes through our lives, like pregnancy or aging, we’ll need re-assessments of what our optimal diet should be.
For now, it’s striking that it took big data and A.I. to reboot our perceptions about something as fundamental as what we eat. We’re still a ways away from “You Paleo, me Keto,” but at least we’re finally making progress, learning that there is no such thing as a universal diet.
Eric Topol (@EricTopol), a cardiologist and professor of molecular medicine, is the executive vice president of Scripps Research. He is the author of the forthcoming “Deep Medicine,” from which this essay is adapted.
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