Changing your diet to improve your health is nothing new—people with diabetes, obesity, Crohn’s disease, celiac disease, food allergies, and a host of other conditions have long done so as part of their treatment. But new and sophisticated knowledge about biochemistry, nutrition, and artificial intelligence has given people more tools to figure out what to eat for good health, leading to a boom in the field of personalized nutrition.

Personalized nutrition, often used interchangeably with the terms precision nutrition or individualized nutrition is an emerging branch of science that uses machine learning and “omics” technologies (genomics, proteomics, and metabolomics) to analyze what people eat and predict how they respond to it. Scientists, nutritionists, and health care professionals take the data, analyze it, and use it for a variety of purposes, including identifying diet and lifestyle interventions to treat disease, promote health, and enhance performance in elite athletes.

Increasingly, it’s being adopted by businesses to sell products and services such as nutritional supplements, apps that use machine learning to provide a nutritional analysis of a meal based on a photograph, and stool-sample tests whose results are used to create customized dietary advice that promises to fight bloat, brain fog, and a myriad of other maladies.

“Nutrition is the single most powerful lever for our health,” says Mike Stroka, CEO of the American Nutrition Association, the professional organization whose mandate includes certifying nutritionists and educating the public about science-based nutrition for health care practice. “Personalized nutrition will be even bigger.”

In 2019, according to ResearchandMarkets.Com, personalized nutrition was a $3.7 billion industry. By 2027, it is expected to be worth $16.6 billion. Among the factors driving that growth are consumer demand, the falling cost of new technologies, a greater ability to provide information, and the increasing body of evidence that there is no such thing as a one-size-fits-all diet.

The sequencing of the human genome, which started in 1990 and concluded 13 years later, paved the way for scientists to more easily and accurately find connections between diet and genetics.

When the term “personalized nutrition” first appeared in the scientific literature, in 1999, the focus was on using computers to help educate people about their dietary needs. It wasn’t until 2004 that scientists began to think about the way genes affect how and what we eat, and how our bodies respond. Take coffee, for instance: Some people metabolize caffeine and the other nutrients in coffee in a productive, healthy way. Others don’t. Which camp you fall into depends on a host of factors including your genetics, age, environment, gender, and lifestyle.

More recently, researchers have been studying connections between the health of the gut microbiome and conditions including Alzheimer’s, Parkinson’s, and depression. The gut microbiome, the body’s least well-known organ, consists of more than 1000 species of bacteria and other microbes. Weighing in at almost a pound, it produces hormones, digests food that the stomach can’t, and sends thousands of different diet-derived chemicals coursing through our bodies every day. In many respects the microbiome is key to understanding nutrition and is the basis of the growth in personalized nutrition.