When I was experiencing severe GI issues, post-concussion syndrome, and debilitating chronic pain, there was almost nothing I wouldn’t do to get better. Every doctor I spoke to seemed to use the same mental model: try this new medication and schedule a follow up, with any sort of dietary intervention mentioned as a complete afterthought rather than a foundational starting point. It took months of self-directed research and dietary experimentation to finally get some results and getting this piece right was what ultimately laid the foundation for my journey back to health.
It’s not that these doctors didn’t care, or that they weren’t very knowledgeable in their field. It’s that nothing in their medical training treats dietary and lifestyle interventions as clinical tools. The average medical school allots only a handful of hours to nutrition over four years. It’s this lack of focus that makes diet become something that’s only mentioned in passing rather than something you build a treatment plan around.
Years later, I was put in touch with a doctor who subscribes to the “Lifestyle Medicine Model”, a framework built around six pillars: nutrition, physical activity, restorative sleep, stress management, social connection and avoidance of risky substances. On the surface this seemed like exactly the sort of thing that I was missing during my recovery, and something that could shape the future of how medicine is practiced. A model built specifically around diet and lifestyle as foundational pieces is in my mind the best way to support healing and is the only way to truly resolve the modern chronic illness epidemic.
However, correctly diagnosing the problem, and making recommendations grounded in the best available evidence are two different things. The more I looked into the actual philosophical and scientific underpinning of the lifestyle medicine model, the more I became skeptical that this really was evidence based medicine, rather than consensus opinions built on weak associative data.
Nutrition Philosophy Problems
The American Collage of Lifestyle Medicine (ACLM) recommends “an eating plan predominantly on a variety of minimally processed vegetables, fruits, whole grains, legumes, nuts and seeds” as the foundation of its nutritional pillar. This recommendation is based on the exact type of research I criticized in my blog post: why nutrition research is unreliable. Nutrition science cannot run controlled experiments over the decades chronic disease takes to develop, so it splits into short, loosely controlled, interventional trials too brief to capture real outcomes, and long, real-world cohorts so uncontrolled and statistically adjusted that there is no real useable signal. ACLM’s core citations fall into both of these camps: a meta analysis of observational data on vegetarian and vegan diets, a review of loosely controlled small scale interventional trials, and small uncontrolled case series work with a large number of confounding variables. The result is not causal evidence, nor any sort of hard science evidence, but rather a pile of weak signals all pointing in the exact direction due to them all suffering from overlapping experimental design flaws.
There’s an additional bias underneath all of this research, which is what actually gets studied in the first place. Researchers set out to ask how plant-predominant eating (usually in replacement of processed foods) affects cardio-metabolic health. In these studies, they never looked at how ancestral diets like Paleolithic diets, Ketogenic diets, or Carnivore diets affect the same measures. Therefore, all that the ACLM’s cited research can actually say is that plant-based eating might convey some benefits over conventional ultra-processed diets (the word “might” is required here because the weak cited data cannot establish cause and effect). It cannot claim that cutting out meat or swapping out an ancestral diet for a plant-based diet conveys any sort of benefit.
The omission of ancestral diets from the cited material is most likely not an accident. The director of the ACLM’s own economic research arm is also the founder of a separate plant-based research advocacy organization and a former executive director of one of America’s most prominent plant-based advocacy foundations. When the people setting a field’s research agenda are already committed advocates for one conclusion, it’s no surprise that only one side of the research is cited. Understanding all of this, when you see that the ACLM recommends predominantly plant-based eating, what you’re really looking at isn’t a neutral synthesis of the best evidence, but the output of a field that decided its answer before it even finished asking the question.
What Real Evidence Literacy Looks Like
If we can’t properly rely on nutrition studies in human beings to make recommendations, what should we use instead? The most common answer is mechanistic reasoning, which focuses on the specific biochemical pathways that explain how compounds in food affect the human body, building toward a clearer picture of species-appropriate dietary patterns. This approach has real merit, but it has to be handled with caution. Mechanism can mislead just as easily as a bad cohort study, especially when a single pathway gets fixated on in service of a conclusion someone already wanted.
To use mechanistic reasoning properly, the first place to start isn’t the pathway, but rather our evolutionary environment. What foods were humans actually eating throughout our evolutionary history, and what does the hard science evidence tell us about what the human body is adapted to process and thrive eating? I’ve made this case in detail in [previous post link], but the short version is that our physiology was shaped by a predominantly animal-based diet for the vast majority of our evolutionary timeline. Departure from our ancestrally consistent diet is the thing that needs justifying, not the reverse. From there, mechanism becomes useful: not as a free-floating explanation invented to fit a conclusion, but as the layer that explains how a system built for that evolutionary reality responds to a given input. Evolutionary evidence anchors the question and mechanism explains the answer; neither one is sufficient alone.
Who You Should Actually Trust
None of this means a lifestyle medicine certification is worthless, or that a nutritionist, functional medicine, naturopathic or any other holistic credential automatically means the opposite. A certification tells you that someone has at least been exposed to the material but it ends up being a weak proxy measure for if someone is actually making recommendations grounded in the best available evidence. I’ve seen MDs who’ve done the real work of digging into primary literature and come out with genuinely sound, individualized recommendations. I’ve also seen nutritionists and holistic practitioners repeat the same weak associational claims discussed above. The letters after someone’s name tell you what room they sat in. They don’t tell you whether they learned to ask the right questions once they got there.
What actually matters is narrower, and harder to credential. It’s whether someone is willing to hold a recommendation to the right evidence standard before making it, using evolutionary evidence as the anchor, mechanism that explains rather than justifies, and convergent data where it genuinely exists. It means using this full wide lens range of evidence, instead of falling back on whatever’s easiest to cite or most repeated by other credentialed voices.
This is the standard I hold my own practice to and it doesn’t end at a diploma. Between roughly 700 hours of formal nutrition coursework and another thousand or so of independent research since, I regularly come across information that sounds true on first pass but doesn’t survive being checked against evolutionary evidence and mechanism together. That’s not a failure of my training, but rather what applying a real evidence standard is supposed to produce. It’s what gives me the confidence that I can look at an individual that comes to me and give them the best chance at getting the results they’re looking for.
If you’re interested in seeing what true evidenced based nutrition looks like firsthand, book a free discovery call and let’s see how we can use the full weight of the research to help you achieve your health goals.