Slow Metabolism Symptoms: What You Need to Know

Written by: Angela Myers
Medical Reviewed by: Ecler Ercole Jaqua, MD, MBA, DABOM

Metabolism is a vital foundation of overall health, and it affects much more than just the number on the scale. Your metabolic rate impacts your energy, mood, ability to think clearly, and more. Here’s how to spot slow metabolism symptoms as well as natural ways to support your metabolic health.  

When you see the word “metabolism,” what’s the first thing that comes to mind? If “weight management” popped into your head, same here. Yet, while metabolism helps us burn calories, it also does so much more. It plays a crucial role in our energy levels, mood, and even body temperature regulation. That means the next time you’re able to finish a workout or get through a long work day, you can in part thank your metabolism. That’s also why slow metabolism symptoms can be so concerning. 

The signs of a slow metabolism are broad and far-reaching: feeling fatigued, hair thinning, digestive problems, to name a few. Since many of these symptoms also relate to other medical conditions, it’s important to differentiate when slow metabolism is to blame, as well as science-backed ways to boost it.

What is metabolism? 

Metabolism is the sum of the processes within the body that turn food into energy. Yes, this includes burning calories, which plays a role in how much we weigh. But metabolism is actually the foundation for health since your body uses the energy from metabolism to digest food, to circulate blood, to think clearly, to breathe, and to regulate body temperature. 

“Think of it as your body’s internal engine,” says Mark J. Tager, MD and member of the Veracity doctor team, “It’s running all the time—whether you’re sleeping, eating, or exercising—breaking down food into energy and building back the parts of you that need repair.”

It also doesn’t work the same for everyone. Genetics, age, certain health conditions, medications, and lifestyle influence how your metabolism operates. No matter the current speed of your metabolism, it is a work-in-progress, meaning it can change at any time. “What’s important to remember is that metabolism isn’t fixed,” explains Dr. Tager, “You can influence it—for better or worse—through how you eat, move, sleep, and manage stress.”

If you’re wondering what your exact metabolic rate is, you can calculate your basal metabolic rate (BMR), which is how fast your metabolism works when you’re resting. There are tools to get a rough estimate based on your age, height, and weight. 

To calculate your true BMR, testing is done under very strict lab conditions (after an overnight sleep and prolonged faster and in a thermoneutral environment). Most clinics, however, measure resting metabolic rate (RMR) with indirect calorimetry, a measure of how much oxygen someone consumes and how much carbon dioxide they produce, which provide a more accurate estimate than at-home tools. This estimate is taken in a temperature-controlled room when you’re mentally and physically calm, ideally 12 to 14 hours after your last meal.  

10 signs of slow metabolism 

Slow metabolism symptoms can be far-reaching since this process that touches almost every area of health:

• Persistent fatigue or low energy

• Unexplained weight gain 

• Cold intolerance

• Dry skin and/or hair

• Hair thinning

• Reduced ability to exercise

• Brittle nails

• Digestive symptoms like constipation or bloating 

• Brain fog

• Weight “sticking” despite consistent habits

To be fair, most of these symptoms could describe at least two other health conditions, which is why it’s hard to differentiate if metabolism or something else is the cause. 

“One red flag that metabolism may be part of the problem is when you’re following a healthy lifestyle—a balanced diet, regular activity, decent sleep—and you’re still gaining or unable to lose,” says Dr. Tager.

When this is the case, he often recommends lab testing insulin levels, fasting glucose, and sometimes levels of thyroid hormones. These tests can reveal if your metabolism isn’t working as intended and provide a chance to course correct, which may involve lifestyle changes and treatment to manage any underlying medical conditions (more on those below).

Metabolism killers 

Habits that quietly slow down your metabolism are sometimes referred to as metabolism killers. Most will probably look familiar, but it’s always good to have a refresher:

• Lack of sleep: Getting enough quality sleep helps regulate appetite while sleep deprivation increases hunger and insulin resistance, though direct effects on basal metabolism are small.

• Chronic stress: Ongoing stress often leads to the release of more cortisol, which is commonly referred to as the “stress hormone,” though it also stimulates appetite. When there is more cortisol in the body, you often eat more. Stress can also cue your body to store more fat, slowing down metabolic processes in the process.

• Rapid weight cycling and extreme diets: “If you cut calories too harshly or skip meals constantly, your metabolism doesn’t ‘break’—it adapts by slowing down to conserve energy,” says Dr. Tager. This slowdown is a natural, protective response when the body perceives energy to be scarce, but it can slow metabolism over time.

• Sedentary lifestyle: The speed of metabolism is significantly impacted by your non-exercise activity thermogenesis (NEAT), which is time and energy expended on activities that aren’t sleep or exercise. If you sit for long periods of time, you would have a lower total daily energy expenditure (via a lower NEAT), which can tip the balance toward slower metabolic processes. 

• Losing or not building muscle: When you lose muscle mass or don’t actively build muscle through strength training, more fat cells may develop in the body. Fat cells don’t burn as many calories as muscle, meaning metabolism will be less efficient. 

• Ultra-processed diet: Foods that are high in sugar, unhealthy fats, and salt (aka ultra-processed foods) don’t provide the body with the necessary nutrients for proper digestion and may increase inflammation, both of which indirectly affect metabolism. 

Age didn’t make the list but deserves an honorable mention. Our metabolism changes as we get older. Aging also brings with it a higher chance of losing muscle mass, which burns more calories than fat.

While kids and young adults tend to have faster metabolisms, it’s not inevitable that metabolic health will get significantly slower with age, says Dr. Tager. He adds, “With resistance training, enough protein, good sleep, and balanced hormones, you can preserve much of that metabolic vitality well into older age.”

How to boost your metabolism 

If any of the signs of a slow metabolism resonated, you may be looking for something that will boost yours. An efficient metabolism doesn’t come down to just one thing; it’s a mix of factors, including the ones below. 

Get adequate protein

“Protein is especially powerful because your body works harder to digest it than it does carbs or fat, and it helps preserve muscle,” says Dr. Tager. The exact amount of protein you need depends on your activity level and age, but the minimum recommended amount per day is 0.36 grams per pound per day, but most experts recommend 2.2 to 3.5 grams per pound per day in order to maintain muscle and metabolic health, especially in older or active adults. Popular protein sources include eggs, peanut butter, chicken, fish, legumes, and beans.

If you have trouble getting enough protein, you can sneak in more by adding protein powders to smoothies, yogurt, or water.

Eat a well-balanced diet

It’s a myth that any one food, including protein, will supercharge your metabolism on its own. Instead, eating a well-balanced diet supports a healthy metabolism. What exactly does that entail? More whole foods than processed ones (the more ingredients on the label, the more processed a food probably is), as well as adding fruits, veggies, sources of fiber, like quinoa or oats, herbs, and spices to your plate.

Sample one-day metabolism-friendly menu

For a better idea what a balanced diet looks like, here’s a one day sample menu:

• Breakfast: Greek yogurt with berries and nuts, served with a green tea or matcha 

• Lunch: Salmon or chickpeas served on a bed of quinoa with roasted veggies

• Snack: One serving of fruit or nuts (such as apples, blueberries, almonds, or walnuts—pick your favorite) 

• Dinner: Chicken or tempeh served with sweet potato and Brussels sprouts
  
  

Strength train regularly

“Strength training a few times a week—lifting weights, using bands, or even bodyweight exercises—can really rev up your baseline burn,” says Dr. Tager. This is because strength training builds muscle, which burns more calories than fat, speeding up metabolism. 

Incorporate smart cardio

Cardio (running, biking, swimming, etc.)increases total energy expenditure during the session, providing a temporary but usually modest metabolism boost. Following the CDC’s recommendation of getting at least 150 minutes of moderate-intensity aerobic exercise or 75 minutes of high-intensity aerobic exercise can help support your metabolic health. A leisurely bike ride, brisk walk, or slow jog may fall into the moderate-intensity category while sprints, HIIT classes, and fast bike rides fall into the high-intensity camp. 

Increase your NEAT 

Metabolism is not just about hitting the gym. It’s also affected by your NEAT (non-exercise activity thermogenesis), the energy you expend on any activities that are not technically exercise. When you move in any way, even if it’s not a formal workout, you burn more calories than you do when sitting still—and that increases your metabolism. 

While office jobs keep many of us sedentary for much of the day, here are some NEAT ways (pun intended) to boost metabolism:

• Take movement breaks throughout the day

• Set a daily step goal for yourself and track on a watch, phone, or other device

• Take the stairs instead of the elevator

• Park further from your destination to get more steps in

• Make social events active: walk with a friend instead of meeting at a café

• Swap nightly TV time for an evening walk
  

Practice stress management

Having regular practices in place to manage stress, such as meditation, breathwork, or yoga, can help regulate the release of hormones like cortisol, leading to a more efficient metabolic process. 

A cool thing about the nutrition and movement tips we already discussed is that they decrease stress as well. 

Consider adding research-supported supplements 

Alongside a balanced diet, some supplements can support efficient metabolism. Three Dr. Tager recommends include:

• Catechins or caffeine: These substances increase calories burned for a few hours, and are naturally found in coffee, green tea, and matcha. 

• Combined herbal formulas: Specifically, Dr. Tager recommends a blend of hibiscus and lemon verbena, as in Metabolism Ignite. Early studies suggest lemon verbena may aid sleep/stress which may help with metabolism, and hibiscus may modestly affect metabolism. 

• Magnesium: This essential nutrient (also included in Metabolism Ignite) offers over 300 enzymes, including ones used in energy production and glucose regulate; in some studies, supplementation has led to favorable effects on glycemic control, which plays a role in metabolic processes.  
  
  

Special life stages and conditions

Another key consideration is what life stage you’re in—and if you have any medical conditions that affect metabolism. For example, as you get older and during menopause, your body composition changes, often making it harder to maintain muscle. 

Menopause, the time when a person stops menstruating, and perimenopause, the years leading up to it, also reduce the production of estrogen, which may increase excess weight around the waistline and reduce insulin sensitivity, making weight regulation more difficult. 

Aside from these life stages, specific medical conditions can disrupt metabolism too, such as: 

• Polycystic ovary syndrome (PCOS): “People with PCOS often have higher levels of androgens (male-pattern hormones) and more insulin resistance, which together disrupt metabolism,” says Dr. Tager. The result? A hormonal environment where the body processes and stores food more slowly. 

• Insulin resistance: With this condition, the body’s cells become less responsive to insulin. “The body has plenty of insulin floating around, but the cells aren’t listening to it well,” says Dr. Tager, “That means glucose doesn’t get into the cells efficiently, and instead of being used as fuel, it lingers in the bloodstream and often gets stored as fat.” This can slow metabolism and, if untreated, may lead to high blood sugar, metabolic dysfunction-associated steatotic liver (formerly nonalcholic fatty liver disease), and other health concerns. 

• Hypothyroidism: Thyroid hormones help control metabolism and growth. When the thyroid doesn’t produce enough thyroid hormone (a state known as hypothyroidism), the entire metabolic process slows as well.

• Cushing syndrome: This condition occurs when the body produces too much cortisol, a hormone that plays a role in metabolism. The excess of cortisol has a ripple effect, slowing down the entire metabolic process. 

The good news? All the tips above to boost metabolism work when a medical condition or life stage is at play. Just remember that the ideal equation to get metabolism on track: lifestyle changes plus proper medical support, which will look different for each of these conditions. 

Testing and when to see a clinician

If experiencing symptoms of a slow metabolism, it’s worth bringing it up to your healthcare provider during your next wellness checkup or physical. They may order tests and/or labs to determine your basal metabolic rate, insulin levels, fasting glucose, and levels of thyroid hormones. They can also review any medications, such as antidepressants or steroids, and lifestyle factors that might affect your metabolism.

If you’re experiencing rapid or unexplained weight change, severe fatigue, hair loss, menstrual changes, or depressive symptoms, it’s a good idea to see your provider sooner. Additionally, people with certain conditions, such as type 2 diabetes or any of the conditions above, may want to consult an appropriate specialist (i.e. an endocrinologist, in the case of diabetes) about any slow metabolism symptoms.  

Key takeaways

• Metabolism is a complex series of chemical processes in the body that promote overall health. It helps you think, produce enough energy for everyday life, regulate body temperature, and maintain a healthy weight.

• Slow metabolism symptoms include fatigue, hair loss, cold intolerance, weight gain, dry hair or skin, and an inability to lose weight.

• If metabolism is slow, it’s best to focus on lifestyle changes, such as exercising more often, increasing NEAT (or non-workout) movement, eating a balanced diet, managing stress levels, and taking supplements that support overall health

• There are also specific life stages and medical conditions which impact metabolism, making it important to consult a healthcare provider if experiencing slow metabolism symptoms. 

• When an underlying condition is present, it’s important to treat it alongside implementing lifestyle changes. 

FAQs

How do I tell if my metabolism is slow?

A slow metabolism is usually marked by symptoms such as weight gain, an inability to lose weight, hair loss, dry hair or skin, difficulty regulating body temperature, brain fog, and fatigue. If you start to notice these signs, consult your healthcare provider to rule out any underlying symptoms, and come up with a plan—including lifestyle changes—to support your metabolism. 

What is the root cause of slow metabolism?

There is no single root cause of a slow metabolism. Instead, a variety of factors may play a role, including stress, diet, activity levels, and age. Certain underlying medical conditions, like polycystic ovary syndrome (PCOS) or insulin resistance, can disrupt the metabolic process as well.

How to speed up metabolism?

Speeding up metabolism often comes down to making decisions and forming habits that are good for your overall health. Eating a well-balanced diet, strength training two to four times a week, engaging in a minimum of 150 minutes of moderate aerobic activity weekly, managing stress, and taking certain supplements can all help support efficient metabolic processes. Many underlying conditions, including hypothyroidism and insulin resistance, impact metabolism too, which is why it’s important to consult a healthcare provider if you’re experiencing slow metabolism symptoms.  

What are the signs of good metabolism?

Signs of a healthy metabolism include maintaining a healthy weight and having consistent energy levels. A robust digestive system, as well as the abilities to appropriately regulate body temperature and think clearly are also signs of a healthy metabolism.