Why This Functional Medicine Expert Uses Immunity (Not BMI) To Determine A Healthy Weight

To start, it's important to acknowledge that weight itself is just adipose tissue—it's neither good nor bad. Different people can carry different amounts of weight and still be quite healthy. If we can think about healthy weight in this way rather than fixating on arbitrary number, good things will happen. I think we'll see less guilt and shame in our society and more equitable treatment of people despite their socioeconomic status. To put this into practice, I've got a few tips and tricks to suggest below, but it all starts with BMI.

In my experience, BMI is quite simply the wrong way to approach weight. It's a one-size-fits-all approach to medicine in a world that now offers more nuanced solutions. On top of all that, it can be unjust and discriminatory.

These socioeconomic determinants of health—everything from education and housing to employment, criminal justice, and access to health care—matter, and our reliance on BMI as an easy shorthand for health only furthers the structural racism present in our current medicine.

We know that people can be overweight but metabolically healthy or have a normal weight but poor metabolic health. Why? Because the immune system plays a big role in whether our fat cells are healthy and happy or angry and damaging to the rest of our bodies. When immune cells called macrophages get activated to an inflammatory state, our fat cells start to create molecules that further promote inflammation. Think of your immune system as the switch that can turn healthy weight into unhealthy weight.

Rather than BMI, I'd like to offer three alternative ideas to help you connect the dots between your weight and your health. These are ways to harness your body's complementary systems to make friends with your weight and stop obsessing about any single number:

Research shows that when fat cells start getting inflamed, we start experiencing poor health. This means maintaining immune balance and keeping inflammation in check is key to maintaining a healthy weight. The Mediterranean diet is a big winner here, so eat more foods rich in plant nutrients and healthy fats. For more on immune balance, learn about a process called immuno-rejuvenation. It's the reason I started my new company, Big Bold Health.

The gut is a major gateway to the health of our entire bodies. This is especially true as it relates to our fat cells. Everything from your gut microbiome to the integrity of your gut wall may influence your fat cells, so paying attention to gut wellness is key. A good balance of prebiotics and probiotics can really help here.

Hormones like insulin, ghrelin, and leptin are big players when it comes to fat cells, as are a number of lesser-known hormones like GLP-1 and GIP. Maintaining the right balance of these signals may strongly determine whether our fat cells are healthy or unhealthy, as well as our overall weight. Bitter foods like Himalayan tartary buckwheat are a great way to improve this signaling. (More on that unique ingredient here.)

It's so important that the story around weight gets past BMI. We need to start thinking about the ways in which fat cells become polarized toward an unhealthy state by unexpected players like your immune system, your microbiome, and endocrine signals. It's a more complex conversation than BMI, but it's the only way to think about weight inside the larger story—the one that really matters—of overall health and social justice.