Does Metabolism Increase in Winter? The Truth Behind Cold-Weather Calorie Burn

September 22, 2025 •

4 min read

According to a study on hikers, people can burn significantly more calories in colder temperatures. This is due to a natural bodily process called thermogenesis, which is why, yes, metabolism increases in winter as your body adapts to the chill.

Quick Summary

Yes, metabolism increases in winter as your body expends more energy to maintain core temperature through involuntary shivering and activating brown fat. However, this boost is often offset by other factors like reduced activity levels and increased appetite.

Key Points

Metabolism increases in cold: Your body expends more energy in winter to maintain its core temperature, increasing your metabolic rate through thermogenesis.
Shivering and non-shivering thermogenesis: Heat is generated through involuntary muscle shivering and the activation of brown fat, both of which burn calories.
Brown fat is a key player: This specialized tissue burns fat to produce heat and can become more active with regular, mild cold exposure, improving your overall metabolic efficiency.
Behavioral factors can negate the boost: The tendency to eat more and exercise less in winter often outweighs the metabolic increase, leading to potential weight gain.
Leverage the cold for better results: Instead of relying solely on the cold, combine it with regular physical activity and mindful eating to maximize the metabolic benefits.
Individual responses vary: Everyone's metabolic response to cold is unique, and factors like genetics, body composition, and level of acclimatization play a role.

The Science of Thermogenesis: How Your Body Stays Warm

Thermogenesis is the process by which your body produces heat. When the air temperature drops, your body's survival instincts kick in to prevent hypothermia by increasing heat production. This requires energy, which in turn elevates your metabolic rate. This heat generation occurs through two primary mechanisms.

Shivering Thermogenesis

This is the most obvious and recognizable way your body responds to the cold. When your body's core temperature begins to drop, your muscles involuntarily contract and relax rapidly. This shivering action produces heat as a byproduct of muscle movement and can significantly increase your metabolic rate, in some cases by up to five times your normal resting rate. While effective, it is a short-term, high-energy-cost response.

Non-Shivering Thermogenesis

For sustained periods of cold exposure, your body activates a more efficient, long-term heat-generating process. This is primarily driven by a special type of body fat called brown adipose tissue, or brown fat. Unlike white fat, which stores energy, brown fat burns calories to produce heat. When exposed to cold, your nervous system releases norepinephrine, a hormone that signals brown fat cells to become active and start burning stored energy. This process helps regulate body temperature without the need for constant shivering.

The Role of Brown Fat in Winter Metabolism

Babies are born with high amounts of brown fat to help them stay warm, but the amount decreases with age. In adults, brown fat is typically found in small deposits around the neck, collarbones, and spine. Research has shown that regular exposure to cold can lead to a phenomenon known as “browning” or “beiging,” where white fat cells begin to take on the calorie-burning properties of brown fat, further enhancing non-shivering thermogenesis. A 2013 study found that exposing adults to cool temperatures for 10 days resulted in a significant increase in brown fat. This adaptation allows the body to generate more heat and burn more calories over time, not just in acute cold situations.

The Winter Weight Gain Paradox

Despite a higher metabolic rate, many people gain weight in the winter. This seemingly contradictory phenomenon can be explained by several behavioral and physiological factors that can override the metabolic boost.

Reduced Physical Activity

Colder weather often leads to a more sedentary lifestyle. People tend to stay indoors more and reduce their participation in outdoor activities. The energy saved by this reduced activity can easily outweigh the marginal increase in metabolic rate from mild cold exposure.

Increased Calorie Intake

Winter is often associated with comfort foods and holiday celebrations, leading to an increase in appetite and calorie consumption. Studies suggest that cold exposure can increase ghrelin levels (the hunger hormone) and decrease leptin levels, driving individuals to eat more. This added caloric intake can quickly surpass the extra calories burned through thermogenesis.

Hormonal Shifts

Seasonal changes in daylight hours can impact hormones like melatonin and serotonin, which can affect mood and appetite. Some individuals experience Seasonal Affective Disorder (SAD), which can lead to increased sleep and changes in eating patterns.

Comparing Cold and Warm Weather Metabolism

To understand the full picture, it's helpful to compare how the body's energy use and habits differ between seasons.


Feature	Cold Weather (Winter)	Warm Weather (Summer)
Thermoregulation	High activity (shivering & non-shivering) to generate heat.	Low activity; focuses on heat dissipation (sweating).
Metabolic Rate	Elevated to produce heat, especially in cold environments.	Lower, as less energy is needed to maintain core temperature.
Physical Activity	Often reduced due to weather and staying indoors.	Typically higher due to more opportunities for outdoor activities.
Appetite & Calorie Intake	Often increased due to hormonal shifts and comfort eating.	May decrease as the body's core temperature is naturally higher.
Brown Fat Activity	Activated to burn calories for heat, can increase over time.	Less active and contributes less to total energy expenditure.
Weight Management	Can be challenging due to decreased activity and increased eating.	Easier for many to maintain due to higher activity and lower appetite.

How to Leverage the Winter Metabolic Boost

Instead of viewing the metabolic increase as a guaranteed weight-loss hack, consider it a potential advantage to be utilized strategically. Regular, intentional cold exposure combined with a balanced diet and consistent exercise is the key. For instance, cold water immersion therapy and outdoor winter workouts can enhance the thermogenic effect. You can learn more about the broader concept of how your metabolism works here: Cleveland Clinic.

Conclusion: The Whole Story

While a higher metabolism in winter is a fascinating biological reality, the practical implications are more complex than simply freezing your way to fitness. The human body is a master of adaptation, and the increased calorie burn from thermogenesis is often a subtle change. For significant, lasting results, focusing on a holistic approach that includes consistent physical activity, balanced nutrition, and managing seasonal habits is far more effective. Understanding how your body works in the cold allows you to make informed decisions and truly optimize your health year-round.

Frequently Asked Questions

Yes, shivering can burn a significant number of calories because it involves rapid, involuntary muscle contractions. Some studies suggest it can increase your metabolic rate by up to five times your normal resting rate, but this is a short-term, energy-intensive response.

White fat stores energy, while brown fat burns energy to create heat. In cold temperatures, brown fat is activated, increasing calorie expenditure. While most adults have a small amount of brown fat, regular cold exposure can increase its activity.

Relying on cold exposure alone is not an effective or safe weight-loss strategy. The metabolic boost is often minimal and easily counteracted by increased calorie intake or decreased physical activity. A balanced approach combining diet and exercise is most effective.

Many people gain weight in winter because they consume more calories, engage in less physical activity, and experience hormonal changes that affect appetite. These factors can easily outweigh the slight metabolic increase from colder weather.

Mild cold exposure, such as taking a cool shower, turning down the thermostat slightly, or spending time outdoors in cold weather, can activate brown fat. Pairing this with exercise can further enhance the effect and potentially convert white fat to beige fat.

Exercising in the cold can be more effective for calorie burning because your body is already working harder to stay warm. The combination of physical activity and cold exposure amplifies thermogenesis. However, it's crucial to listen to your body and dress appropriately.

Yes, your diet plays a significant role. A balanced diet with enough carbohydrates and fats provides the necessary fuel for your body to generate heat effectively. Eating enough protein is also important for maintaining muscle mass, which influences your overall metabolic rate.