How Nutrition Science Has Misled Us

Nutrition should be simple: eat foods that keep you healthy, strong, and satisfied. Yet for decades, the public has been tossed around by confusing, often contradictory headlines—red meat is bad, fat is dangerous, grains are heart-healthy, carbs are fuel. How did we get here?

A big part of the problem lies in the science itself. Nutrition research, especially the kind that dominates headlines and informs dietary guidelines, is built on a shaky foundation: nutritional epidemiology. That’s the science that looks at groups of people naturally living their lives, collects data like health outcomes and lab results, and tries to correlate that with what they think they ate over time. To call this a low quality of evidence isn’t a judgment. It’s well-accepted that this level of evidence is weaker than most others. Yet it’s used as the primary science for health and nutrition. And that doesn’t help us as individuals.

Weak Science, Big Claims

On the surface, it may sound reasonable to look at large groups of people, survey their eating habits, and then track their health outcomes over time. But the method is riddled with problems: people can’t accurately recall what they ate last week, let alone last year. Food questionnaires oversimplify complex diets. And crucially, these studies are observational—they can find correlations, but they cannot prove cause and effect.

Even when correlations are found, the effect sizes are tiny. A hazard ratio of 1.3—commonly reported in studies linking red meat or saturated fat to disease—means only a 30% relative increase in risk, with the absolute increase in risk infinitesimally smaller. For comparison, the hazard ratio linking smoking and lung cancer is 15–20. That is a 1,500-2,000% relative increase in risk. Yet nutrition researchers often treat small, shaky correlations as if they were groundbreaking discoveries.

The Problem With Lumping Foods Together

Another flaw lies in how food categories are defined in epidemiological studies. For example, the category of “saturated fat” can come from wildly different meals:

• A grass-fed steak with broccoli and cauliflower.
• Pasta with meat sauce and bread.
• Steak sandwich on highly processed bread.
• Ice cream and cookies.

All of these contribute saturated fat, but the overall “dietary matrix”—the combination of foods, nutrients, and context—is completely different in each of these meals. Yet studies lump them together as if they’re equivalent.

This makes it impossible to apply the findings to someone eating a low-carb, whole-food diet that includes steak, eggs, and butter as opposed to someone who is eating a carton of ice cream. The data just doesn’t apply—but the conclusions are written as if it does.

We Don’t Eat Nutrients, We Eat Food

The core mistake of nutrition science is reductionism: breaking foods down into isolated nutrients and blaming or praising them in isolation. People don’t sit down to a plate of “saturated fat.” They eat food, and that eating occurs within a context.

A steak with vegetables and olive oil has a profoundly different effect on metabolism than a piece of cake with frosting—even if both technically contain saturated fat. When we lose the nuance of the dietary matrix, we end up demonizing entire foods based on incomplete science.

Why Metabolism Matters

Another piece missing from most nutrition research is our metabolic state. What we do with the food we eat depends not just on the food itself, but on the health of our metabolism.

When insulin levels are low and well-regulated, our bodies can burn both the fat we eat and the fat we store. Dietary fat in this context can be used efficiently for energy, and our bodies are satisfied.

But when insulin levels are chronically high, as happens with insulin resistance and metabolic dysfunction, the picture changes. The body’s ability to burn fat is impaired. Instead of being oxidized for energy, fat is more likely to be stored. The same food that promotes balance and energy in a healthy person can drive weight gain in someone who is metabolically unwell.

This means that blanket statements about “saturated fat” or entire food groups like “meat” ignore the critical role of context—not only the foods we pair them with, but also the metabolic health of the individual eating them.

Healthy User Bias

Then there’s the problem of healthy user bias. For decades, the public has been told that eating red meat and saturated fat is unhealthy. So who tends to eat them anyway? The studies clearly demonstrate that it’s people who are less concerned with following health advice—who also smoke, exercise less, or eat more processed foods. Meanwhile, those who avoid red meat are more likely to exercise, take vitamins, and eat more vegetables.

When studies compare these two groups, it’s no surprise they find different health outcomes. But is that because of the meat? Or because of all the other lifestyle factors bundled together? It’s nearly impossible to untangle. Yet the headlines always point the finger at meat or fat.

The Wrong Lessons

Given these limitations, it’s reckless to base population-wide dietary guidelines on such weak evidence. Suggesting we all reduce saturated fats and animal foods ignores the nuance of food quality, dietary context, and metabolic individuality. It also downplays the fact that animal foods containing saturated fat are some of the most nutrient-dense foods available. They provide high-quality protein, iron, zinc, vitamin B12, and other essential nutrients in forms our bodies can easily absorb.

What Really Matters: Metabolic Health

Instead of targeting single nutrients or demonizing entire food groups, nutrition science—and dietary guidelines—should focus on outcomes that actually matter: metabolic health.

A metabolically healthy person has stable blood sugar, low levels of inflammation, good insulin sensitivity, and a healthy body composition. Achieving that doesn’t come from following abstract rules about avoiding “bad” nutrients. It comes from eating foods that are satisfying, nutrient-dense, and minimally processed.

And it comes from respecting metabolism by ensuring insulin is low and responsive, so the body can efficiently burn both the carbohydrates and fats it consumes.

Time to Raise the Bar

Nutrition science has misled us by overinterpreting weak evidence, ignoring context, and promoting guidelines that don’t reflect how people actually eat—or how human metabolism actually works. It’s time to demand better:

• Stronger evidence. Controlled clinical trials of adequate length should take precedence over food-frequency questionnaires.
• Focus on context. Food should be studied as part of a dietary matrix, not as isolated nutrients.
  
• Outcome-driven guidance. The real question is: Does this way of eating improve metabolic health? If the answer is yes, we should support it for that individual.

Until then, we should be cautious about sweeping claims that tell us to eat less of the very foods—like meat and eggs—that have nourished humans for millennia.