Here’s How To Improve Your Metabolic Health
Experts discern whether at-home microbiome kits are science-backed or just full of sh*t.
Experts discern whether at-home microbiome kits are science-backed or just full of sh*t.
You might think about your metabolism in terms of speed—if you have a fast one it can allow you to eat well without gaining weight; if a slower one, it may make it harder to keep the pounds off. But metabolism isn’t just about weight, and the number on the scale is just one measurement of good health. For a comprehensive picture of your overall wellness, doctors track five markers to determine what’s called your metabolic health. What is metabolic health? In a nutshell, it’s a measure of good health—and few people have what is considered good metabolic health.
A study published in 2018 found that only about 12 percent (1) of people in the United States could be considered metabolically healthy. Why that’s worrying: poor metabolic health increases your risk for health complications down the road, like cardiovascular and other diseases, erectile dysfunction, and non-alcoholic fatty liver disease.
Fortunately, you’re not doomed for disease. Adopting the right tools may help improve your metabolic health over time, so you’re more likely to live longer, and healthier, for years to come.
Metabolism is far more complex than weight. Your metabolism involves all the chemical reactions in your cells that convert food or stored energy into fuel. When you eat, your food is broken down into compounds like amino acids (from protein), fatty acids (from fats), and simple sugars (from carbs), which are absorbed into the bloodstream and shuttled to the cells.
In the cells, those compounds are used for functions such as growing new cells, repairing tissues, and storing energy or broken down further to release energy that powers your bodily functions.
Your metabolic health is a measure of how well your body tackles these processes without medications.
Metabolic health is a health status. If you are metabolically healthy, it means that you have optimal levels of certain metabolic markers and so a low risk of cardiometabolic diseases, according to research published in the journal Metabolic Syndrome and Related Disorders.
Cardiometabolic diseases—including Type 2 diabetes, heart disease, and chronic kidney failure—are the leading cause of death around the world (2). From 1990 to 2017, more than 4.8 million people ages 25 to 64 died from cardiometabolic diseases in the United States (3).
Having subpar metabolic health may harm your health long before it causes major physical illness. Research has found links between poor metabolic health and depression, (4) acne, and skin tags (5).
Researchers have identified five primary markers of metabolic health:
To be considered to be in peak metabolic health, all five of these markers should be within a healthy range without the help of medication.
When this cluster of conditions occurs together, they are referred to as metabolic syndrome and increase your risk of heart disease, stroke, and type 2 diabetes.
For men, a waist circumference—a measure at the narrowest part of your middle—greater than 40 inches is considered a risk factor for metabolic disease; in women, it’s 35 inches.
A fasting blood glucose of less than 100 mg/dL is considered normal; anything higher is a risk factor for metabolic disease. You also want a hemoglobin A1c—a measurement of your blood sugar levels over the past 3 months—to be below 5.7%.
Your blood pressure reading is given in millimeters of mercury (mm Hg) and involves two numbers. The top number (systolic pressure), measures the pressure in your arteries when your heart beats. The bottom number (diastolic pressure), measures the pressure in your arteries as the heart relaxes between beats. A reading above 120/80 is a risk factor for metabolic syndrome.
Another marker for metabolic health is triglycerides, a type of fat from the food we eat which is stored in fat cells in the body. A triglyceride level under 150 mg/dL is considered optimal for metabolic health
A standard lipid panel can measure triglycerides as well as HDL (“good”) and LDL (“bad”) cholesterol. HDL is considered “good” cholesterol because it aids in the process of removing some LDL from the body. It is an important marker of metabolic health. To be considered metabolically healthy, men’s HDL cholesterol should be higher than 40 mg/dL; women should aim for an HDL greater than 50 mg/dL. But the higher it is, the better.
In a nutshell, lifestyle factors—including diet, activity level, stress, and sleep—may often be the cause of worsening metabolic health, although some underlying conditions can factor in.
Since your metabolic health involves how well your body produces and uses energy, a good marker of your metabolic health status is blood sugar or glucose levels. A diet high in refined carbohydrates and processed foods—and low on fiber, healthy fats, and protein—can lead to less-than-optimal metabolic health. Diet is just one factor. But glucose level offers a good talking point regarding some of the causes (6).
When you eat, your body turns carbohydrates (like sugars and starches) into glucose. If you haven’t eaten in a while, your cells can turn glycogen—energy stored in your muscles and liver—into glucose. Your body can also make its own glucose.
When glucose levels rise, it signals your pancreas to ramp up the production of insulin, a hormone that regulates your blood sugar and moves glucose out of the blood and into the cells, where it is used for energy or converted and stored for future use. Eventually, your blood sugar level goes back down.
If your blood sugar regularly remains high—because you eat a steady diet of refined carbohydrates, for example—your pancreas pumps out more and more insulin to attempt to get that glucose into cells. Eventually, your cells can become less sensitive to all that insulin. Your pancreas can also stop making enough insulin. Either way, the result is the same: you will ultimately have a higher fasting blood glucose.
The trajectory of consistently high blood sugar may go like this: First, you may have insulin resistance, which rarely has symptoms and can begin developing for years before tests for prediabetes or diabetes show results (7). Insulin resistance can then lead to prediabetes, which can then lead to Type 2 diabetes.
A fasting blood glucose level of 100 to 125mg/dL is considered a prediabetes state. And 126 mg/dL or higher is consistent with Type 2 diabetes. Diabetes can lead to major health issues, from eye and gum disease to whole body vascular issues.
Glucose is also a good talking point for why metabolic health matters. It is estimated that more than 133 million people in the United States have some type of insulin resistance in the form of prediabetes or diabetes. The latter is the seventh leading cause of death in the US.
About 1 in 5 people with diabetes don’t even know they have it. Many people likely aren’t aware that they have prediabetes either. After analyzing data from the National Health and Nutrition Examination Survey (NHANES) covering 2009–2016, researchers found that more than half of adults in their survey had a fasting glucose 100 mg/dL or above.
Diabetes is just one possible outcome of worsening metabolic health. When metabolic health is less than optimal, inflammation may wreak havoc on your body, potentially impacting energy levels, mood, cognition, skin, hormonal health, and more (8).
Metabolic dysfunction is associated with obesity in a chicken-egg scenario that can create a vicious cycle. Obesity (9) may cause insulin resistance, which may further worsen metabolic health. But insulin resistance may also cause you to store excess fat and make losing extra weight or controlling appetite more difficult.
Some aspects of poor metabolic health may also cause damage at the cellular level (10). Lining the inside of your heart, and blood vessels is a thin membrane called the endothelium, one of the largest organs in your body. The endothelium is made up of trillions of cells, and it interacts with nearly every bodily system. High blood sugar and insulin resistance may lead to endothelial dysfunction, or impaired functioning of this lining, which is associated with cardiovascular disease (11).
Endothelial dysfunction can also cause erectile dysfunction by limiting the dilation of blood vessels needed to get or maintain an erection (12). Erectile dysfunction may be one of the early clinical signs of endothelial dysfunction and a clinical marker for worsening metabolic health, according to the researchers of a small study published in 2013 in Clinical Research in Cardiology (13).
A decrease in metabolic health may also affect hormone levels. Insulin resistance has been associated with reduced testosterone levels (14), though researchers haven’t figured out exactly why this is.
One theory: increased visceral fat leads to higher levels of proinflammatory cytokines, leptin (a hormone that helps regulate body weight), estradiol (a form of estrogen), and insulin, which may inhibit the activity of the hypothalamic–pituitary-gonadal (HPG) axis.
The hypothalamus, a region of the brain and a part of the HPG axis, produces and releases gonadotropin-releasing hormone (GnRH). GnRH then stimulates the pea-shaped pituitary gland, located at the base of the brain, to produce and secrete luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Then LH activates testosterone production in the testicles. Disruption along this crucial axis can impact testosterone levels.
Some enzymes in fat tissue also convert testosterone to estradiol. Research has found an association between low T levels and insulin resistance, as well. On the other hand, in one study, higher T levels (15) were correlated with markers of metabolic health, including lower body fat and reduced blood sugar levels, which may suggest that having normal testosterone levels may help ward off metabolic disease, but more research is required.
For women, it was the opposite. Higher levels of testosterone were linked to insulin resistance and higher blood sugar and body fat. Research suggests that estrogen may have a protective role in the development of insulin resistance and its consequences. This protection tends to disappear with lower estrogen levels—such as those experienced at the onset of menopause (16).
Improving metabolic health can have dramatic effects on overall health and well-being. Several lifestyle factors can play a role in our metabolic health status, including activity levels, stress levels, and the amount of sleep we get.
Since one of the root causes of worsening metabolic health is high blood sugar, improving blood sugar control is one of the key ways to improve metabolic health. The best way to do that: Eat fewer refined carbs, added sugars, and highly processed foods. That’s not to say you can’t eat carbs at all. Aim to eat ones with a lower glycemic index, and pair them with some fiber, healthy fats (like omega 3 fatty acids), or protein to slow digestion and curb a blood sugar spike.
The time you eat can also play a role. Eating late at night can impair glucose tolerance and increase the risk for Type 2 diabetes, according to a randomized crossover study published in Clinical Nutrition. (17) The study authors suggest that eating dinner earlier may result in better glucose tolerance. Maintaining normal blood sugar levels may help improve metabolic health.
When you exercise, your body increases its responsiveness to insulin. This increases the body’s ability to pull glucose into your cells without the need of insulin, and to use that glucose for energy. This can lower blood sugar and may help to prevent insulin resistance (18). Exercise is also a great tool to help mitigate a blood sugar spike after a meal, according to various studies (19).
However, exercise at any time throughout the day can have metabolic health benefits. Physical activity can improve heart health, helps maintain or reduce body weight, help lower blood pressure, and aid with stress relief.
Stress can cause higher glucose levels (20). When you’re frazzled, stress hormones (think names like adrenalin, cortisol, and epinephrine), primed by your flight-or-fight response, tell the liver to give you glucose so that you can tackle or run from a perceived threat.
Problem is, your body can perceive lots of things as threats: a work deadline, an argument, a traffic jam. Normally, when glucose floods your system, your body pumps out insulin to lower your blood sugar level. But during a stress response, cortisol impairs insulin’s action, causing the body to be less sensitive to it. If this happens over and over again—the case when you’re under chronic stress—it may lead to a problematic cycle that may contribute to the development of insulin resistance (21).
Reducing your overall stress levels and calming your reaction to stressful events can improve metabolic health. Meditation, breathing exercises (22), and physical activity are all ways to help.
Our sleep-wake cycle (a circadian rhythm) is also tied to our metabolic health via the suprachiasmatic nucleus (SCN.) The SCN, located in the hypothalamus, is your body’s master clock and plays a role in metabolic processes.
Erratic sleep schedules, travel, shift work, too much blue light from devices late at night, and an inadequate amount of sleep can all throw your circadian rhythm out of whack (23). These disruptions may affect metabolic health by impacting the delicate balance of hormone levels, and they are tied to insulin resistance and higher body fat. One small study found that one night of inadequate sleep (only four hours) impaired glucose tolerance (24).
Aim for at least seven or more hours of sleep per night and stick to a regular sleep schedule as much as possible. Getting an adequate amount of natural light during the day and restricting light from devices at night may also help (25).
Some underlying conditions can impact metabolic health markers, so staying on top of your overall health and seeking treatment for undesirable symptoms is crucial. Hypothyroidism may affect your glucose level, for example (26). Low testosterone in men and PCOS in women are risk factors for insulin resistance. And sleep apnea, especially if untreated and causing excessive daytime sleepiness, may also put you at risk for worsening metabolic health (27).
Metabolic health means having optimal levels of certain metabolic markers and so a low risk of related diseases. Taking steps to improve your metabolic health may help boost your energy, help you lose weight, improve your mood, and even may increase your longevity by helping to reduce your risk for heart attack, stroke, and other serious life-threatening medical concerns. Even if you don’t have optimal levels of all five metabolic health markers now, you can still be on a path to improved overall health and well-being. Lifestyle changes to diet, activity level, sleep quality and quantity, and stress level, as well treating underlying conditions—like hormone imbalances—can give you a leg up on your metabolic health.