Pragmatic Ways To Flex Your Metabolism, From A Nutrition Ph.D.

Metabolism is thankfully no longer viewed as an inflexible "card" you're dealt thanks to your genes. In fact, metabolism and metabolic health are wonderfully malleable. As such, we can be empowered to lean into key lifestyle factors and personalized approaches to optimize our metabolic trajectory (and since metabolic health and longevity go hand-in-hand, that's a life-altering trajectory to shape).

Below are 9 pragmatic strategies (choose one and build from there!) to improve metabolic health in sustainable ways. These science-backed and expert-informed approaches represent opportunities we can lean into to flex our metabolism and actually see results.

Holding your muscles (and thus, strength and physical function) on a pedestal each day and throughout life is probably one of the best strategies for a long, healthy life. Sufficient (instead of adequate) protein intake is paramount in this endeavor, as is physical activity.

Ann Kulze, M.D., physician, nutrition expert, bestselling author of Eat Right for Life, and founder of The Healthy Living School®️ underscores these tried-and-true pillars of whole foods and regular movement. "Colorful plant-laden nutrition and daily physical activity that preserve muscle mass, fuel an active metabolism, and nurture long-term cardiometabolic health are foundational."

Metabolic scientist and author of Why We Get Sick Ben Bikman, Ph.D., makes sure that he and his family consume "a lot of protein and whatever fat that comes with it." Meanwhile, he practices a relatively lower-carb approach.

When it comes to physical activity, all movement is welcome, but make sure to prioritize muscle-building/preserving activities. Alexis Cowan, Ph.D., Princeton-trained metabolic health expert and mindbodygreen podcast guest, explains why building muscle mass via resistance training is so important. "Muscle is the primary site of metabolic heat production. The more muscle one has, the more energy will be dissipated as heat in the body."

When I asked my friend Whitney Crouch, RDN, CLT, an integrative registered dietitian who helps women recover their health from thyroid, gut, and sex-hormone-related issues, for her top metabolic health-promoting strategies, she had two. First, lift weights. Second, don't demonize carbs since the right kind of carbs are important.

More specifically, Crouch recommends that her clients "lift heavy weights two to three times per week." She says to "start with weights that feel like you're putting in effort (we're not talking circa 1980 Jazzercise!) and that you can still maintain good form while lifting. Then, work your way up over time with both the weight and frequency per week of your sessions, and work with a trainer if you're new to the lifting world and your budget allows."

As with most health considerations, your gut is an important cornerstone. When you eat for the gut-metabolism axis, your gut microbial ecosystem will flourish, and your metabolic health will thank you. A healthy gut even supports energy expenditure.

Megan Rossi, Ph.D., R.D., The Gut Health Doctor and author of How To Eat More Plants, explains that "when we're fixating on calories, we completely forget about the gut microbiome and how important that is for regulating metabolism."

In my opinion, life's too short to count calories. Instead, I recommend that people enjoy an array of healthful foods and the wonderful nutrition they are extracting. My gut-metabolism recommendations are hydrate (water), plants (fiber), color (phytonutrients and other antioxidants), complemented with high-quality protein and healthy fats (especially omega-3s and omega-9s). 

Cowan echoes this approach, recommending a diet with sufficient "protein to maintain and grow muscle, as well as polyphenols to mitigate [inflammatory processes] and optimize the gut microbiome." 

Melina Jampolis, M.D., physician nutrition specialist, podcast host, and bestselling author of Spice Up, Slim Down, shares that "nourishing our gut and maintaining proper energy balance by consuming more plants (fiber but also herbs and spices), healthy fats, and quality protein, while remaining active throughout life are some powerful ways to reclaim our metabolic health." 

After dinner, metabolic researcher Bikman avoids eating for the rest of the night since "the single greatest predictor of a good night's sleep is if I go to bed on an empty stomach," he shares.

Whether through intermittent or circadian fasting, corralling our food intake into a designated time window is known to promote metabolic health, and it's an evidence-based longevity nutrition approach.

Working at the interface of metabolic and mental health, Harvard psychiatrist and author of Brain Energy Chris Palmer, M.D., asserts that, "as long as the person is not underweight or malnourished, the single most powerful intervention to improve metabolism is to go without food for a period of time, or at least make your body think that it is."  

One of the most powerful ways I have found to get tuned into my metabolism is by partnering with integrative-minded health care practitioners who are experts in hormone health, like my personal endocrinologist Brittany Henderson, M.D.

Metabolism and metabolic health are directly affected by numerous hormones (thyroid, sex, insulin, cortisol, etc.), so the opportunities for personalized and incremental gains on the metabolic optimization front are massive.

Some basal level of toxin exposure (think plastics, pollution, etc.) in this modern world is unavoidable. These endocrine-disrupting chemicals (EDCs) can negatively impact our liver and metabolic health. Thankfully, our body has organs dedicated to 24/7 detoxification pathways, although we should help reduce the toxic burden whenever possible. 

While BPA and glyphosate might come to mind, perhaps a less discussed toxin that's incredibly pervasive is alcohol. Creator of Functional Sobriety and functional medicine nutritionist Brooke Scheller, DCN, CNS, shares that, "one of my key recommendations is cutting out (or cutting back) on alcohol use to support metabolic health. Alcohol consumption even a few times per week can affect our metabolism through gut changes, hormone imbalances, and even altering stress hormones2." 

Deshanie Rai, Ph.D., FACN, vice president of global scientific and regulatory affairs at OmniActive Health Technologies, shares, "The role of plant-based bioactives in increasing energy expenditure and metabolic rate have become an area of interest for both academic scientists and consumers and thereby effectively support weight wellness goals."

To provide a practical example, just look at the chili (cayenne) pepper. Rai explains that "we can lean into the intrinsic power of capsaicinoids from chili peppers, as a metabolism-energizing approach," with science to boot: "There is ample evidence via human research showing that capsaicinoid ingestion can boost metabolic rate8, as well as emerging evidence for a role of capsaicinoids in supporting lipolysis9 (fat breakdown), satiety10, and positively influencing body composition11."*

Excess adiposity, insulin resistance, and leptin resistance are a trio to avoid (or improve). Obesity reduces insulin sensitivity12 over time. That insulin resistance makes us less metabolically flexible, making fat and calorie burning difficult. And insulin resistance feeds into leptin resistance, further exacerbating fat metabolism and regulation.

Family physician Bindiya Gandhi, M.D., previously explained that in working with her clients struggling with leptin resistance, "there's one very important factor that's often missing in the conversation about healthy, sustainable weight management and metabolism. Enter: hormones, namely, leptin." 

Leptin is an adipokine hormone13 produced by our fat cells and is directly related to adiposity levels. When working properly, leptin tells our brain that we're full from eating and that enough fat has been stored up. Wonky leptin spells metabolic disaster. Some key leptin resistance contributors are long-term stress and insulin resistance.

Cardiometabolic health expert Cate Shanahan, M.D., says, "If you want to do one thing in 2023 to optimize your metabolism, I would start with getting a blood test called HOMA-IR." An equation that uses fasting blood glucose and insulin lab results, HOMA-IR is a way to estimate insulin resistance.

The fact is many of our country's adults and youths have poor glucose control (i.e., blood sugar balance) due to suboptimal insulin sensitivity. Cowan shares an incredibly practical and powerful tip to move the needle on insulin resistance: "Perhaps the simplest and most effective strategy at improving metabolic health is by moving your body after each meal. Even a 10- to 15-minute post-meal walk can dramatically increase glucose clearance into muscle."

Cowan expounds on the mechanism: "Insulin resistance reduces the muscle's ability to take up glucose out of the circulation following carb-containing meals. Elevated blood sugar levels drive fatigue and brain fog and inflammatory and microvasculature issues over time." That's where exercise comes in, she says. "Exercise is vital for the reversal of insulin resistance and enhanced glucose clearance. Muscular contraction directly stimulates glucose uptake in an insulin-independent manner. A post-meal walk provides sufficient muscular contraction to clear a significant amount of extra glucose from the bloodstream."

That's why a particularly recent technology excites Cowan: continuous glucose monitors (CGMs). She shared that this innovation is "becoming available to the general population at a reasonable cost and with access to user-friendly app interfaces." (If you're looking for a product recommendation, a great CGM example would be Levels.)

"CGMs allow individuals to access critical information about their body's unique response to different foods and meals, sleep quality, stress, and movement. Wearing a monitor for even a few short weeks can provide enough actionable insights to design a personalized diet and lifestyle protocol for an individual and give them rapid and sustainable results. Moreover, the CGM allows individuals to correlate changes to their blood glucose with their felt experiences within their bodies."

When it comes to promoting insulin sensitivity, along with a plant- and fiber-rich dietary pattern and physical activity, I can't forget to shout out my favorite nutrient, vitamin D! A growing body of clinical research links vitamin D sufficiency with cardiometabolic health benefits by promoting healthy levels of glucose and insulin.

The fact is that any improvement on the glucose and insulin front is critical. "Optimizing for glucose metabolism and insulin sensitivity is the game-changer for longevity and protection against serious health concerns chronic diseases including those in the cardiovascular, cognitive, and metabolic realms," Cowan concludes.

Inflammatory processes unchecked are like a fire that's not put out in time. Inflammatory chronicity is a major contributor to metabolic dysfunction and future health concerns.

Prolonged stress sows metabolic dysfunction via adrenal glands pumping out cortisol in an extended fight-or-flight mode. "You're telling your body there's a saber-toothed tiger behind you, and if you think that there's a saber-toothed tiger behind you the majority of your day, you're going to increase inflammatory markers," Kien Vuu, M.D., previously explained on the mindbodygreen podcast.

Casey Kelley, M.D., ABOIM, functional physician and founder of Case Integrative Health, adds that cortisol "will give you a burst of energy while simultaneously pausing other bodily functions and slowing your metabolism." For all these reasons, you'll want to cut or limit stressors you can control. For the other stress-giving things you can't affect, give yourself grace and lean into healthy coping and resilience-bolstering strategies. Lean into meaningful connections and joy-giving things.