Imagine going on a diet that was customized for your body, taking into account your genetic makeup, gut microbiome, lifestyle and health conditions. That’s the vision of researchers in the Division of Nutritional Sciences, who are among the nation’s leading experts in the growing field of precision nutrition.

On Jan. 25, the Human Ecology Alumni Association hosted a webinar “New Year, New Approach to Nutrition” about personalized nutrition featuring Martha Field and Angela Poole, both assistant professors in the Division of Nutritional Sciences. The talk was moderated by nutrition alumna Lisa Drayer ’96, MA, RD, a nutritionist, author and journalist.

The webinar follows the recent announcement that Saurabh Mehta, the Janet and Gordon Lankton Professor in Human Ecology’s Division of Nutritional Sciences, helped secure a $23 million, five-year grant from the National Institutes of Health as part of a federal investment aimed at customizing nutrition guidance.

“People have found out, frequently from personal experience, that the advice they have been given regarding diet and exercise just doesn’t work,” Poole said. “And it’s not just about will power. Certain dietary advice is more effective for certain people. The tricky part for us scientists is to find out what works best for each person.”

Scientific advancements are now making that possible, Field explained. “The field of nutrition has traditionally focused on prevention of nutritional deficiencies and associated diseases in populations,” she said. “But the science has evolved, and I think a more individualized approach is something we all see as our next goal.”

For example, Field cited a study where participants were assigned to either a low-carb or a low-fat diet. On the whole, both groups lost weight. “But when you begin to look at the individuals, some lost a little, some lost a lot, and some gained weight,” she said.

In another study, researchers monitored participants’ glucose levels, diet, exercise and lifestyle factors, and sampled their gut microbiomes, the bacteria in their digestive systems. “For some people, when they ate a banana, their blood sugar level spiked higher than if they ate a cookie, which is not what you would expect,” Poole said.

What’s going on here?

The answer is likely complicated. That’s because there are many factors that contribute to how each individual responds to the foods they eat.

“There is very likely a genetic component to weight gain,” Field said. “It’s not likely just one gene, but several. Even if your genes increase risk for a certain condition, often that condition doesn’t manifest until you have a second hit. If you’re predisposed to weight gain and you eat chicken wings and French fries every day, you might be in trouble. If you eat a healthy diet and exercise regularly, you may mitigate some of that risk.”

Gut microbiome is also a likely factor. “Many bacteria produce good things that can, for example, protect against colon cancer,” Poole said. But other bacteria can harm our health. For example, some gut bacteria produce a protein when we consume red meat that increases the risk of cardiovascular disease. “If you have those bacteria and you eat red meat, you are in trouble, but if you eat a vegan diet, you will probably be fine. And if you don’t have those bacteria and you eat red meat, not so bad.”

Despite the evidence building in this field, Poole and Field agree there isn’t a sure-fire way to create your own customized diet yet. There are some diets proven to work for specific health conditions, such as the DASH diet – which is lower in sodium and saturated fats – for high blood pressure. Beyond that, most people probably have some idea what they should be eating, they said.

“There are recommendations that are generally good for everyone: more fruits and vegetables, more water and more fiber,” Field said. “It also generally holds true that if you eat less, you are more likely to lose weight. When you get into the details and the variability, that’s what we are trying to better understand. And of course, we should all ask ourselves, what are my health goals and how can I best achieve them?”