The question of whether most ultra-processed foods are metabolically harmful is no longer up for debate. This food category, which includes some of the most obvious dietary offenders like soda, candy, sugary cereals, and baked goods, has been under the microscope for years, and the consensus is clear: most ultra-processed foods are harmful and should be avoided as much as possible.
It’s encouraging to see this issue getting the national attention it deserves. But awareness doesn’t always translate into meaningful change. Many people continue to consume ultra-processed foods daily, and often unknowingly. The term itself isn’t regulated, which means most people don’t fully understand what qualifies as “ultra-processed” in the first place.
So while addressing ultra-processed foods is essential, we have to ask: are we going deep enough?
There’s a larger issue we can’t afford to ignore: approximately 90% of Americans are living with some form of metabolic dysfunction, a silent crisis at the root of many chronic and psychiatric conditions.[*]
The main driver may be the chronic overconsumption of carbohydrates, particularly refined and high-glycemic carbohydrates that disrupt insulin regulation and impair metabolic function.
Research into metabolism allows us to examine the process by which our cells convert food into energy, as well as what happens when this process goes awry. Beyond food processing, we need to look at physiological processing. This means turning our focus away from terms like “processed foods” and putting an emphasis on food components, specifically macronutrient ratios and nutrient density.
We interviewed two experts in the field of metabolic health to assess the big picture around the current health crisis and where food and metabolism fit in. Read on for valuable insights from Dr. David Ludwig, a Harvard endocrinologist and leading researcher on diet and obesity, and Gary Taubes, a renowned science journalist and bestselling author known for challenging conventional nutrition science.
Food Categories Aren’t Enough: The Limits of “Ultra-Processed”
The term “ultra-processed” was introduced as part of the Nova food classification system to categorize foods based on their level of processing.
According to Nova, ultra-processed foods can be defined as:[*]
“Industrially created food products created with the addition of multiple ingredients that may include some Group 2 ingredients (food products that have been processed by pressing, refining, grinding and/or milling) as well as additives to enhance the taste and/or convenience of the product, such as hydrolyzed proteins, soy protein isolate, maltodextrin, high fructose corn syrup, stabilizers, flavor enhancers, non-sugar sweeteners, and processing aids such as stabilizers and bulking and anti-bulking agents.”
While certainly a step in the right direction, according to Dr Ludwig, the “ultra-processed” label is too broad a term and hard to regulate.
“After all, this is a concept that was coined by one team in Brazil in 2009. So that’s very recent, scientifically. It’s never been revised and updated and taken apart and reassembled by other teams. There are, in fact, dozens of systems for classifying foods based on processing. Is this the best? Maybe. But I think what we all want to know, or should want to know, is whether this is the right system to base our public health policy on.” —Dr. David Ludwig
For example, flip over a pint of Häagen-Dazs vanilla ice cream and you’ll see only four ingredients, placing this product outside of the ultra-processed foods category. Pick up the pint next to it, which contains more additives, and you’re looking at an “ultra-processed food.”
Whether it’s labeled “ultra-processed” or not, your brain and metabolism respond to what’s inside the carton. When chronically consumed, foods high in sugars and carbohydrates can drive metabolic dysfunction, including blood sugar instability, inflammation, and oxidative stress; factors that are increasingly linked to nearly every chronic disease, including serious mental health conditions.
The Sugar Illusion: Why Natural Isn’t Always Better
In recent years, natural sugars have achieved a similar health halo to foods deemed minimally processed. Both categories make one massive assumption: because this food came from nature, it must be good for us.
The reality is that unprocessed sugary foods still cause blood sugar spikes and insulin surges. That means your lavender latte sweetened with local honey could still send you on a glucose rollercoaster, especially if your metabolism is already damaged.
If we’re looking at food quality from a metabolic standpoint, it’s always going to come down to how your body processes the nutrients. You could have the most nutrient-dense superfood-filled meal imaginable, but if the carbohydrate content is too high for your metabolic machinery, it’ll drive your insulin and glucose up and further contribute to chronic disease.
The bigger takeaway is that it always comes back to the current state of your metabolism. For those with impaired metabolic health, the distinction between “natural” and “processed” may matter less than the actual macronutrient load.
A Real-World Wake-Up Call: The Cook Family Story
In July 2020, 34-year-old Kristina was in crisis. Over 200 pounds, overwhelmed by anxiety, PTSD, and exhaustion. Her 11-year-old daughter Genevieve was also spiraling, battling multiple psychiatric diagnoses and intense episodes that required physical interventions to keep her safe.
The family had tried it all—therapy, medication, specialized programs—but nothing stuck. Medications sometimes made things worse. Desperate for a lifeline, Kristina began exploring metabolic health.
Their first breakthrough came with a whole foods diet. Cutting out seed oils, sugar, and grains brought noticeable changes: Kristina’s energy improved, her pain eased, and she lost nearly 80 pounds. But Genevieve’s hallucinations persisted, and Kristina’s mind remained foggy and anxious.
Everything changed when they found ketogenic therapy. Within three days of switching to a therapeutic ketogenic diet, Kristina experienced mental clarity for the first time in her life. And Genevieve? “That noise in my head that made me feel crazy—it’s gone,” she said. The hallucinations stopped.
Cutting out processed foods brought some relief, but the real breakthrough came when they went a step further. By addressing their underlying metabolic dysfunction through ketogenic therapy, they unlocked a level of healing that no medication or standard treatment had been able to provide—an incredible example of why sometimes going beyond processed food labeling is needed.
So, what was happening beneath the surface? Why did cutting carbs and shifting into ketosis trigger such dramatic improvements for the Cook family?
To understand the power of this shift, we have to look beyond food labels and dive into how the brain actually makes and uses energy. Because for people facing serious metabolic and mental health challenges, there’s often a deeper issue at play: the brain isn’t getting the fuel it needs to function.
Addressing the Energy-Demand Dysfunction
The emerging science of metabolic psychiatry shows that for many people, especially those facing serious mental illnesses, the brain may not be getting the energy it needs to function properly.
If glucose isn’t entering brain cells effectively, ketones (produced through a ketogenic diet) can serve as an alternative fuel. But ketogenic therapy isn’t just about bypassing glucose; it may also help repair and retrain the brain’s ability to utilize carbohydrates more efficiently over time.
Oftentimes, addressing this energy-demand dysfunction takes more than just avoiding processed snacks. It requires targeted metabolic interventions, starting with the macronutrients that directly fuel the brain.
So how did our national focus shift toward “ultra-processed foods” while largely ignoring the deeper issue of carbohydrate and sugar overconsumption?
Part of the answer lies in the quality of the nutrition research we’ve relied on for decades.
Poor Quality Studies Distort Public Perception
Take, for example, a highly publicized NIH study that set out to test the carbohydrate-insulin model of obesity—the idea that a low-carbohydrate diet reduces caloric intake and fat storage. In the trial, participants spent two weeks on an animal-based ketogenic diet, then immediately switched to a plant-based low-fat diet for another two weeks (or vice versa).
Dr. Ludwig points out that adapting to a low-carbohydrate or ketogenic diet takes weeks (not days) and that short-term studies like this often miss this crucial metabolic transition. When keto seems to “fail” in two-week trials, it’s usually just capturing the body’s adjustment phase, not the full metabolic effect of the diet.
In the first week, calorie intake was nearly the same across both diets. But by week two, those on the low-carb diet began to eat fewer calories, suggesting the model might be correct. The controversy came after the crossover: in weeks three and four, participants who had just switched to the low-carb diet suddenly ate significantly more calories than those switching to low-fat. Eventually, their calorie intake began trending down again.
Despite this back-and-forth pattern, the study concluded that low-carb diets led to higher calorie consumption overall, directly contradicting the carbohydrate-insulin model. Researchers claimed the diets didn’t influence each other. But two years later, the authors acknowledged there was a major carryover effect—perhaps the largest ever reported in nutrition research—on the order of 2,000 calories per day.
Ludwig and Taubes argue that this flaw undermines the study’s conclusions. Without a “washout” period between diets, participants were still being influenced by the first diet during the second, making the results unreliable. Instead of disproving the carbohydrate-insulin model, the study became a prime example of how poor design and interpretation can mislead both scientists and the public.
In short, weak studies, especially those that are too short or underdeveloped, have distorted how we think about what works. This lack of rigorous science creates confusion and allows bias, not evidence, to shape dietary advice.
“We need definitive knowledge. It is deplorable that we have such a poor database on such fundamental questions that have been debated for a century. We just need to make nutrition research a priority and stop settling.” —Dr. David Ludwig
Ludwig is calling for higher-quality research: studies that last 12 to 24 months, have better funding (just $10–$20 million could make a massive impact), and directly compare diet approaches—like low-carb vs. low-fat vs. low ultra-processed—in real-world settings.
The Takeaway
Public awareness is finally catching up to what many clinicians and researchers have long understood: food can be a powerful driver of chronic disease. The growing concern around ultra-processed foods marks a significant shift in how we think about health, and it deserves real applause. Reducing these foods is a critical first step toward reclaiming metabolic function.
But while this focus is encouraging, it’s just the beginning. Because each individual’s biology is different, addressing metabolic dysfunction requires more than cutting out packaged snacks or sugar-sweetened beverages. A truly therapeutic approach must consider macronutrient composition, mitochondrial health, and the broader landscape of an individual’s metabolic profile.
Classification systems like NOVA have helped spotlight the role of industrial processing in chronic illness, but they often fall short when it comes to guiding specific, actionable interventions, particularly for individuals living with complex conditions like serious mental illness.
To drive meaningful change, we need to go beyond a one-size-fits-all approach. That means recognizing that both the extent of food processing and the types of macronutrients, especially refined carbohydrates and added sugars, contribute significantly to metabolic and mental health outcomes. When we address both, we open the door to more precise, effective, and life-changing nutritional strategies.
What’s Next?
If you’re looking for more information on metabolic psychology and the ketogenic diet, check out Think+Smart, our free community-inspired framework that combines education and collective experience to help individuals employ metabolic therapies to improve mental health.
For the full story of how the Cook family transitioned from the standard American diet to whole foods and ultimately to a ketogenic therapy—with life-changing results—read Kristina’s Story.
For more debates on nutrition science and ultra-processed foods, watch:
- The Truth About Nutrition Science: Is the Government Getting It Wrong?
- The Ultra-Processed Food Debate: Science, Bias & Truth
Both feature Dr. David Ludwig and Gary Taubes unpacking flawed studies, funding biases, and what better research could look like.
For further reading, check out:
Dr. David Ludwig’s paper on Ultra-Processed foods and how the Nova food classification system may not be enough at a national level to support public health.
And Gary Taubes’ Substack, where he writes extensively on the issue of ultra-processed foods.
For more insights from Dr. David Ludwig follow @DavidLudwigMD on X, Facebook, and through Boston Children’s Hospital. And you can connect with Gary Taubes through his Substack “Uncertainty Principles,” or on X, Facebook, and LinkedIn.
