Not losing weight in a calorie deficit: Reasons and strategies

A calorie deficit refers to when a person consumes fewer calories than their body uses through physical activity and basic bodily functions. Keeping within a calorie deficit can help people lose weight and maintain the weight loss.

A person following a calorie deficit diet may reach a weight loss plateau, in which their weight loss slows or stops, despite them sticking to their diet. Weight loss plateaus are common, affecting the vast majority of people who diet to lose weight.

This article describes why weight loss plateaus happen and discusses some strategies for breaking through them. It also offers advice on when to seek help during a weight loss journey.

According to a 2024 review, weight loss plateaus are common, affecting around 85% of people who diet.

During periods of prolonged calorie restriction, the body may conserve energy to help protect against further weight loss. This process is called metabolic adaptation or “adaptive thermogenesis” since it helps to promote survival.

As a 2024 review explains, the following hormone and peptide changes can occur throughout a person’s weight loss journey and may contribute to a weight loss plateau.

Gender-specific hormonal fluctuations may also contribute to a weight loss plateau. For example, a decline in estrogen and testosterone levels during menopause may slow metabolism, reduce muscle mass, and change how the body distributes its fat stores.

Below are some possible reasons for weight loss plateaus.

As the American Council on Exercise (ACE) explains, basal metabolic rate (BMR) refers to the minimum number of calories the body requires to sustain its basic functions, such as breathing and circulation.

A calorie deficit diet can reduce BMR to help conserve energy during severe or prolonged calorie restriction, which can contribute to a weight loss plateau.

Non-exercise activity thermogenesis (NEAT) is the amount of daily energy a person burns through everyday activities that are not considered workouts, such as walking around the house, fidgeting, or doing chores.

According to a 2022 review, a calorie-restricted diet can decrease NEAT. This decrease happens because the body is trying to adapt to a lower energy intake and minimize further weight loss. It is a form of adaptive thermogenesis.

During a calorie restricted diet, the body may begin using muscle tissue as a source of energy. The medical term for this is ‘muscle catabolism’.

Compared to fat tissue, muscle tissue burns calories at a higher rate, even at rest. As muscle mass decreases, the body burns fewer calories. This reduces BMR and slows down weight loss.

A person may reach a weight loss plateau because of difficulty sticking with a particular diet.

A 2023 review notes that people often report the following factors as interfering with their ability to stick with a healthy eating plan:

As the British Heart Foundation (BHF) explains, weight loss is typically more significant during the first few weeks of a new diet or exercise plan. This is because the body is using stored glucose called “glycogen” for fuel. As glycogen stores deplete, they release water, causing a rapid decrease in weight. This is not the same as losing weight though decreasing fat stores, which is typically a much more gradual process.

On the other hand, extreme calorie restriction can mimic starvation and trigger a stress response that increases levels of the stress hormone cortisol. This hormone can increase fluid retention, which in turn will contribute to a person’s weight.

According to a 2024 review, the following health conditions may also cause or contribute to a weight loss plateau:

According to a 2024 review, it is normal for a person to experience short-term weight fluctuations while following a calorie-restricted diet. Factors that can cause or contribute to these fluctuations include:

An apparent increase in weight while dieting may discourage people from sticking to their diet. This, in turn, may contribute to weight gain in the form of increased fat mass.

“If you’re going through menopause, you may find it harder to lose weight because your body is changing. Hormones shift and affect your hunger signals. You lose muscle mass and your metabolism slows down. Poor sleep can also exacerbate weight changes. This multifactorial problem takes a thoughtful approach.”

_{Quotes represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.}

Below are some strategies that could help a person break through a plateau while following a calorie restricted diet.

A 2020 review explains that increasing protein intake may help to support weight loss and improve body composition in both low calorie and standard-calorie diets.

A healthy exercise regimen may help a person overcome a weight-loss plateau while dieting.

Mixing different types of exercise can help burn calories while increasing muscle mass.

Aerobic exercise is particularly effective for burning calories. The American Heart Association (AHA) recommends that adults get at least 150 minutes per week of moderate-intensity aerobic exercise, or 75 minutes per week of high intensity aerobic exercise, or some combination of the two.

Strength and resistance training exercises can help build muscle mass and boost the body’s ability to burn calories. The AHA recommends strength training at least twice per week.

People can also try incorporating more NEAT activities throughout the week.

A person should consider seeing a doctor or dietitian if their weight loss plateau continues for more than a few weeks, or if they start to experience other symptoms. A doctor can run tests to rule out medical conditions that may be causing or contributing to the weight loss plateau.

Most people who diet will reach a weight loss plateau, in which their weight loss slows or stops, despite them sticking to their diet.

A weight loss plateau can happen for many reasons, including adaptive thermogenesis, loss of muscle mass, and a decrease in metabolism.

People can try to increase their protein intake, combine aerobic and muscle-strengthening exercises, and get enough sleep.

Anyone who experiences a weight loss plateau lasting more than a few weeks should consider seeing a doctor to help rule out any underlying health conditions.