Doctor Warns Many Americans Consume ‘Food-Like Substances’ Rather Than Real Food

Nearly half of Americans actively pursue weight loss each year, with approximately 43 million adults following specialized diets such as keto, vegan or Mediterranean regimens, according to recent data. But with countless contradictory dietary approaches available, determining the optimal eating plan can be challenging for many.

Dr. Mark Hyman, a prominent physician, recently addressed this dilemma on his podcast, “The Dr. Hyman Show,” stating that no single dietary approach works universally for everyone.

“The truth is the best diet is the one that works for your biology,” Hyman explained. “We’re all different. There isn’t a one-size-fits-all diet.”

At the foundation of healthy eating, Hyman differentiates between what he terms “real food” and “food-like substances,” a distinction he considers critical in today’s nutritional landscape.

“Food is something that helps support the health and development and growth of an organism,” he said. “Honestly, what most people are eating in America today is not definitionally food. It’s a food-like substance.”

This distinction is more than semantic. Minimally processed foods—those recognizable and close to their natural state—fundamentally differ from ultraprocessed products engineered primarily for convenience and extended shelf life. The nutritional profiles and health impacts of these categories vary dramatically.

Hyman also emphasized that “food is medicine”—not merely similar to medicine but literally functioning as a medicinal substance. “Everything you put in your body is a drug that’s going to help you or harm you,” he noted, explaining that plants contain thousands of bioactive compounds that influence inflammation, detoxification and disease risk.

Blood sugar regulation represents one key factor determining individual responses to different foods, according to Hyman. Diets high in refined starches and sugars can disrupt metabolic health in ways that affect multiple bodily systems.

“If you don’t have balanced blood sugar, if you have high blood sugar or high insulin, this is going to screw up your blood sugar metabolism,” Hyman warned, connecting poor metabolic control not just to diabetes and cardiovascular disease but also to various mental health conditions.

This metabolic connection partly explains the popularity of ketogenic diets, which prioritize high fat, moderate protein and minimal carbohydrate consumption. By sharply reducing carbohydrates, the keto approach shifts the body from glucose metabolism to fat-burning, a state known as ketosis.

Hyman described ketones—energy molecules produced when glucose is limited—as particularly efficient brain fuel, noting that properly implemented keto diets can stabilize blood sugar, reduce insulin levels and decrease systemic inflammation.

However, he cautioned that not all keto approaches yield positive results. “People can make mistakes and it can be bad,” he said, emphasizing the difference between “crappy keto” and versions built around whole foods, vegetables and high-quality fats. “For most people, it’s a tool, not a permanent lifestyle,” Hyman added.

Other popular dietary patterns can also be beneficial when properly tailored. Paleo diets—focused on fruits, vegetables, lean meats, fish, eggs, nuts and seeds—and vegan regimens that exclude all animal products can work well when carefully implemented.

“You can’t be a ‘chips and soda vegan,'” Hyman stressed, highlighting the importance of whole foods regardless of dietary philosophy.

Similarly, Mediterranean diets, widely credited with promoting longevity and cardiovascular health, vary in their implementation. Hyman distinguishes between traditional Mediterranean eating patterns rich in vegetables, olive oil, fish and legumes and modern interpretations that rely heavily on refined bread and pasta products.

“It’s a good foundation, but it’s really about personalized diets,” he said.

Across all dietary approaches, Hyman consistently returns to individual response as the ultimate arbiter of effectiveness. “How do you feel? Does your energy go up? Are your cravings down? Is your sleep better?” he asked, describing the body as “the smartest doctor in the room” that reliably signals whether a particular diet is helping or harming.

“Your biology always tells the truth,” Hyman concluded.

The growing field of personalized nutrition reflects this perspective, with research increasingly suggesting that individual genetic, metabolic and microbiome differences significantly influence dietary responses. This individualized approach represents a significant shift from traditional one-size-fits-all dietary recommendations that have dominated nutrition guidelines for decades.

Health experts recommend consulting with healthcare professionals before adopting any new eating pattern, particularly for those with existing medical conditions. While the right diet can function as preventive medicine, determining which approach best suits an individual’s specific biology requires careful consideration of multiple factors.