6 Markers Of Metabolic Health You Should Keep In Mind, From Functional MDs

The cliché sentiment "you can't judge a book by its cover" certainly rings true when it comes to metabolic health. 

While historically, many experts saw weight and obesity as the main issue, it's now clear that's far from the truth. "Obesity is just another marker of metabolic health; it's not the cause," says neuroendocrinologist Robert Lustig, M.D., and author of the upcoming book Metabolical: The Lure and the Lies of Processed Food, Nutrition, and Modern Medicine. "It's downstream of the metabolic problem; it's not the metabolic problem itself."

In fact, 20% of people considered "lean" are still metabolically unhealthy1. 

"Your waist circumference is very important, more important than your weight," says Lustig.

For men, a waist circumference greater than 40 inches would be considered a risk factor of metabolic disease, and for women it's 35 inches. "That's measured at your waist, right above your hip bones, usually at the most narrow part of the waist," says Foucher-Urcuyo. "As metabolic syndrome takes its toll, gaining weight in that abdominal region can add a lot of risk."

Lustig says it's important to note that your visceral (belly) fat only makes up about 4 to 6% of your total body fat, so you won't necessarily see it reflected on the scale. What's more, he says what matters most in this region is your liver fat, which is nearly undetectable without further tests. "The lab test that's the most sensitive is an ALT test, which is on a standard panel," he says, adding that he would consider anything over 25 ALT a red flag (although now, due to current patient averages, over 40 is the new upper limit).

"One of the most important markers to me is blood sugar levels before and after eating," says Jeffrey Bland, Ph.D., the father of functional medicine and founder of Big Bold Health.

While your pre- and post-eating blood sugar levels may be a bit harder to test in a regular medical setting, the comprehensive metabolic panel (CMP) does cover your fasting blood glucose. As for proper levels? "A fasting blood glucose of less than 100 mg/dL is considered 'normal,' but most functional doctors prefer for that number to be at around 70 or 80 mg/dL," integrative doctor Kristann Heinz, M.D., R.D., previously told mbg.

Foucher-Urcuyo adds that in the context of metabolic health, "having a fasting blood sugar greater than 100 mg/dL, is a sign of insulin or blood sugar problems."

Another thing to consider when measuring metabolic health is triglycerides, which are the end product of digesting and breaking down fats in food. Bland says that knowing blood triglyceride levels is crucial for the evaluation of fat metabolism.

While triglyceride measurement can be a bit complex, generally speaking, "a triglyceride level over 100 is questionable, a level over 150 is usually metabolic disease," says Lustig. You can check these numbers with a standard lipid panel, which is a measure of your HDL ("good") cholesterol, LDL ("bad") cholesterol, and triglycerides.

Some experts, such as board-certified family physician Cate Shanahan, M.D., say it's also crucial to consider your triglyceride-to-HDL ratio. "If the triglyceride number is more than two and half times the HDL, it's an indicator that your body fat is not accepting shipments of new fat quickly enough," she says in a mindbodygreen podcast. "So, the triglycerides stay in your bloodstream for too long."

On that same standard lipid panel, you'll also get a reading of your LDL, or "bad" cholesterol levels.

To promote metabolic health, pediatrician and former commissioner of the FDA David A. Kessler, M.D., recommends keeping those LDL levels low. "You have to keep an eye on that LDL because it varies for people," he says in a mindbodygreen podcast episode.

To take that one step further, Lustig says that in his work, he's found it's not enough to know if you have high LDL—you need to know the type of LDL in question. "Eighty percent of the LDL in your bloodstream is irrelevant, it's buoyant LDL or type A. The 20% that matters is slow dense LDL, or type B," he says.

How can you tell the difference? There's an advanced lipid test you can take called the VAP test, but it's often expensive and not covered by insurance. The easiest way to tell is, yet again, checking out those triglyceride levels. "If you have a high LDL and your triglyceride is low, then it's large, buoyant, and irrelevant," he says. "So you have to look at the path of LDL, not the absolute number."

You've likely considered blood pressure an important health standard all your life, considering the signature cuff is commonplace at most doctors' visits—and it certainly plays a role in metabolic health, as well.

While there isn't an exact standard, Foucher-Urcuyo specifies that a reading of 135/80 is a risk factor for metabolic syndrome.

Shanahan also notes that if your blood pressure is higher than 125/75 on a consistent basis, you could have a mild or more severe metabolic problem. So, be sure to keep track of your past measurements, especially if they've been historically high.

One marker that may be less familiar is uric acid—which is a waste product found in the blood, created when the body breaks down chemicals called purines. High levels of uric acid are commonly associated with gout—a form of arthritis, but that's not the only thing they may indicate, says Lustig.

"Uric acid is basically a proxy for sugar consumption, because of the way uric acid is made in the liver," he says. "If your uric acid is high, that means your mitochondria aren't working well, and you've got a problem."

While metabolic health can seem complex, most experts agree on ways to improve it—which generally boils down to supporting overall well-being. Some top tips from Bland, Lustig, and Foucher-Urcuyo include:

The reality is, metabolic dysfunction is something you could go decades without discovering in your own body. But taking proactive steps to prioritize your metabolic health and well-being right now—meaning actually uncovering what's happening in the pages of that book, not just the cover—can make all the difference in the long run.