A person’s metabolism is the rate at which their body burns calories for energy. The speed of metabolism depends on various factors, including age, sex, body fat, muscle mass, activity level, and genetics.

Calories provide the energy the body needs, not only to move but also to breathe, digest food, circulate blood, grow cells, repair wounds, and even to think. The rate at which the body burns calories to produce this energy is called the metabolic rate.

Scientists use various formulae to measure resting metabolic rate (RMR), also known as resting energy expenditure (REE). RMR and REE refer to the amount of energy a body uses at rest, for example, sleeping or sitting.

The rate can vary between individuals. Factors affecting it include age, sex, and the activity the person is carrying out at the time.

While a person has no control over the genetic aspects of their metabolism, research shows that some strategies may help speed up the rate at which the body processes calories.

It is worth noting that, while speeding up the metabolism may help people burn calories and lose weight, it needs to be part of an overall strategy that includes a healthy and varied diet and regular exercise.

In this article, learn about 10 approaches that may help increase metabolism.

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The body relies on balance and regularity.

In 2019, some researchers suggested that following a regular meal pattern can help reduce inflammation, improve circadian rhythms, increase the body’s ability to withstand stress, and manage gut flora, the composition of bacteria that help keep the gut healthy.

They suggested that the following may provide health benefits:

  • eat breakfast
  • consume most energy-providing foods early in the day
  • eat two to three meals per day at regular times
  • have periods of fasting

The authors also hypothesized that meal timing may play a role in resting energy expenditure. However, the results were not conclusive, and more reseach is needed.

Learn about time-restricted eating, which focuses on the timing of meals to improve health and gain muscle.

Some people skip meals as a way to lose weight. However, this can negatively impact metabolism. Eating meals that are not filling can have the same effect.

Eating too few calories can cause a person’s metabolism to slow down so the body can conserve energy, according to the Academy of Nutrition and Dietetics.

According to current dietary guidelines, adult females aged 19 and over need 1,600–2,400 calories a day, depending on their physical activity levels, and males need 2,000–3,000. During pregnancy and breastfeeding, females will need up to 452 additional calories, depending on the stage.

How many calories should I eat per day?

Reducing calories may not increase metabolic rate, but the choice of foods that provide those calories may do. Protein, for example, may be more likely than carbohydrates or fat to promote thermogenesis, the burning of calories in the body

In a 2020 study, 38 people followed either a high protein diet, with 25% of their calories coming from protein, or a medium protein diet, with 15% of their energy coming from protein. Those who consumed a higher proportion of protein burned more energy than those who consumed less.

Some research has suggested that green tea extract may play a role in promoting fat metabolism.

While the Academy of Nutrition and Dietetics says any increase is likely to be small, green tea may help manage weight and health in other ways.

For example:

  • Consuming green tea instead of sugary sodas and juices can reduce sugar intake.
  • Drinking green tea throughout the day can help a person stay hydrated.
  • The antioxidants in green tea may help reduce the risk of inflammation, cell damage, and heart disease, blood pressure, and cholesterol.

The National Center for Complementary and Integrative Health says it is safe to consume up to 8 cups of green tea a day.

People should speak with a doctor before increasing their intake of green tea or consuming it during pregnancy. It may interact with some medications. During pregnancy, it may increase the risk of birth defects due to low folic acid levels.

Does green tea help with weight loss?

Strength training helps build muscle, and it may slightly increase a person’s rate of metabolism while resting, for example, when they are sleeping or sitting.

The authors of a small 2018 study found that combining resistance training with dietary measures led to a slight increase in metabolic rate, but it was not statistically significant. Participants who did only resistance training saw a reduction in fat mass and an increase in lean mass.

Research suggests that when a person has more muscle mass, their body uses food for energy more effectively. In other words, their metabolism is less wasteful.

In one study, participants who did resistance training for 9 months saw an average 5% increase in metabolic rate, but the findings varied widely between individuals. The researchers suggested that fat free mass (lean mass) and thyroid hormone levels might help account for the variability.

Resistance training may involve lifting weights and doing exercises that use the weight of the body or resistance bands to build muscle.

A previous study, from 2012, found that high intensity interval resistance training also increased metabolic rate. In this study, the rate at which participants’ bodies used energy was higher for at least 22 hours after one training session.

Interval training is highly intensive and may be more suitable for people who are already fit than those who are new to regular exercise.

How can exercise help you build muscle?

Staying hydrated is essential for the body to function at its best. Water is necessary for optimal metabolism, and it may help a person lose weight.

In 2016, scientists assessed the metabolic rate of 13 people who consumed either 250 or 500 milliliters (ml) of water. They found evidence of increased fat oxidation after 500 ml when a person is at rest, and concluded that drinking water may have an impact on metabolism. However, they did not find that it increased metabolic rate.

This may happen because the additional water helps the body burn fat preferentially over carbohydrate.

How much water should I drink each day?

Stress affects hormone levels, and it can cause the body to produce more cortisol than usual.

Cortisol is a hormone that helps regulate appetite. In 2011, researchers found unusually high cortisol levels in people with disordered eating. The body releases cortisol in times of stress.

However, the authors of a small 2020 study found no evidence linking resting metabolic rate and anxiety.

Stress could also have an indirect impact by affecting eating patterns and sleep, both of which can alter the rate of metabolism.

Why does stress happen, and how can I manage it?

People who have less sleep may have a lower metabolic rate, according to research from 2016. The study took place in a sleep laboratory, and participants slept 4 hours per night for 5 nights followed by one night of 12 hours sleep. Their metabolic rate fell after the nights with little sleep but returned to their usual levels after the night of recovery sleep.

The authors believed the body reduces metabolic rate to conserve energy when a person sleeps less. They noted this could lead to weight gain in people who do not get enough sleep.

The need for sleep varies between individuals, but the Centers for Disease Control and Prevention (CDC) recommend that adults aged 18–60 should have at least 7 hours per night.

What should you do if you have trouble sleeping?

Vitamins play an essential role in metabolism.

The results of a rodent experiment from 2018 suggested that a low intake of various B vitamins could impact the rate at which the body metabolizes lipids, including cholesterol and triglycerides.

More research may be needed to understand the relationship between vitamins, metabolism, and weight loss.

A complete guide to B vitamins, types, sources, and more.

Some research has suggested that eating spices such as chili, which contains capsaicin, can increase metabolic rate, including the rate at which the body burns fat and uses energy.

A 2014 study from China found that people who ate spicy food every day were more likely to have a high body mass index (BMI) than those who did not. The researchers noted that more investigations are needed to find out why this happens.

The Academy of Nutrition and Dietetics says that while eating hot chilies might boost metabolic rate temporarily, it is unlikely to have a significant impact.

What are some healthy herbs and spices?

What’s the best way to lose weight?

People with low levels of thyroid hormone may have a slower metabolism.

Thyroid hormone stimulates the production of substances that increase oxygen consumption, respiration rate, and body temperature. This involves a higher rate of energy consumption.

Conversely, the body of a person with hypothyroidism is likely to burn energy at lower rate. Their metabolic rate may be slower, and they may have a higher risk of weight gain and obesity.

For those with hypothyroidism, taking medications that increase the levels of thyroid hormone can increase their resting metabolic rate.

Seeking help for hypothyroidism can help speed up metabolic rate and reduce the risk of complications linked to this condition.

What is hypothyroidism and how can you recognize it?

Here are some answers to questions people often ask about metabolic rate.

What is metabolic rate?

Metabolic rate refers to the rate at which the body uses energy and burns calories. The resting metabolic rate (RMR), also known as resting energy expenditure (REE), refers to the body’s use of energy in a resting condition, for example, when sitting or sleeping. The body uses most of its energy this way.

What is a high metabolic rate?

Metabolic rates vary widely between individuals, so it is not possible to specify a standard or high metabolic rate. However, the higher the rate, the quicker a person will use the energy they take in from food, which may reduce the chance of weight gain.

What can increase metabolic rate?

Factors that may increase a person’s metabolic rate include consuming an appropriate number of calories, favoring protein over carbohydrates and fat, getting enough sleep, and some types of exercise, such as resistance training.

It is not always possible for a person to change their metabolic rate, but exercise and dietary measures may help.

A good metabolic rate may help with weight management. But for those seeking to lose weight, it is better to focus on eating a varied diet with plenty of whole foods and being physically active. While some foods, such as spices, may help boost rates temporarily, they are not a long term solution.

It is always best to speak with a doctor before adjusting the diet or making changes to an exercise routine.