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What causes weight gain in men? Related conditions and treatments

Weight gain in men may be caused by lifestyle habits, some medications, and hormone fluctuations
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By | Apr. 21, 2025 Medically reviewed by Anne Jacobson, MD, MPH
Scale and pill capsule: What causes weight gain in men?

Key takeaways

  • Weight gain in men is a common symptom that may be caused by lifestyle habits, certain medications, medical conditions, poor diet, sedentary lifestyle, lack of sleep, and hormone fluctuations.

  • Typically, weight gain in men does not require immediate medical attention.

  • Weight gain in men generally does not require medical treatment unless it is rapid, significant, or accompanied by other health issues. That said, weight gain will not typically reverse on its own.

  • Treatment of weight gain in men may include diet, exercise, weight loss drugs, and treatment of the underlying cause. Read more about treatments for thyroid issues, low testosterone, chronic kidney disease, and heart failure.

In this article:

Overview: What does weight gain in men look like?

Weight gain isn’t exclusive to men or women, but the way men and women carry that weight differs. Because they have more estrogen, women often see excess fat show up in their thighs and buttocks, while men carry more of it in their bellies. This is why men are more likely to have a “gut” or “beer belly” than women (before menopause).

It’s normal to experience small weight fluctuations from day to day and week to week, but sustained weight gain may present additional health issues or come with other symptoms. These symptoms can include fatigue, lethargy, bloating/swelling, shortness of breath, constipation, and vision issues. Men may also experience some mental health issues, like depression or discouragement about their appearance.

What causes weight gain in men?

Weight gain in men isn’t always as simple as it might seem. It can often stem from a combination of factors, including lifestyle choices, medical conditions, medications, and more. Understanding the underlying cause is the first step to losing some unwanted weight. Here are several of the most common causes.

Eating habits

Most people are familiar with at least one fad diet for weight loss. They aren’t always solid options, but there’s a layer of truth beneath their claims—what we eat can play a significant role in weight management. According to a 2023 study, increased consumption of processed carbohydrates like sugars, starches, and refined grains was associated with weight gain, while eating more whole grains and non-starchy vegetables was not. So limiting sugars and highly processed, high-calorie foods while maintaining a well-balanced diet can help avoid weight gain or shed some extra pounds.

One 2022 study concluded that among people with diabetes, men were more likely than women to engage in unhealthy diets, smoking, and alcohol consumption.

Lack of physical activity

Not only is exercise good for the heart, muscles, immune system, mind, and general well-being, but it’s also often essential to maintain a healthy weight. In fact, a 2022 study concluded that prolonged daily sitting was associated with higher body fat percentages. Conversely, other research has shown that as little as 30 minutes of aerobic exercise per week can result in modest weight loss. In comparison, 150 minutes of moderate-intensity exercise per week can achieve more significant results.

Stress

Whether it’s from a fast-approaching deadline, car troubles, or world events, we’ve all experienced stress. And while temporary stress won’t skyrocket body fat, chronic stress can be a risk factor for weight gain. Stress hormones like cortisol trigger the body’s fight-or-flight response, slowing down any functions not absolutely necessary for survival. That includes metabolism, which is why long-term elevations in cortisol are linked to obesity.

“Stress-induced increases in cortisol can cause fat accumulation for men and women both, but is particularly more significant in men,” says Trista Best, RDN, LD, a registered dietitian at The Candida Diet.

Lack of sleep

Believe it or not, getting adequate sleep can also help with weight management. A study from 2022 found that people who got less sleep tended to have a higher calorie intake, which could cause weight gain. That puts people with sleep disorders, like insomnia or sleep apnea, at a higher risk since they often sleep less than the average person and are more prone to late-night snacking.

“Chronic disorders like sleep apnea are more prevalent in men with excess weight and can exacerbate retention of weight,” says Dr. Michael Chichak, MD, Medical Director at MEDvidi. “Sleep deprivation as a consequence of this condition impacts bodily processes such as metabolism and balance of hormones which makes shedding weight harder.”

Low testosterone

Testosterone is an important hormone for men because it affects muscle development, energy expenditure, and fat storage. A 2015 study in Obesity Review called out a link between low testosterone and fat mass in men. According to Best, low testosterone “leads to increased body fat, slow metabolism, and reduced muscle mass. If this is the cause of a man’s weight gain, it must be addressed before weight loss can occur.”

Men typically produce less testosterone as they age, but low testosterone can also stem from various medical conditions.

Certain medications

Most medications have potential side effects, and for some, that might include weight gain. Not everyone will experience it, but some might. These drugs include:

  • Antidepressants: Some antidepressant drugs can increase appetite, and studies have shown that popular antidepressants like Prozac and Lexapro can lead to some measure of weight gain.
  • Corticosteroids: Prednisone and other corticosteroids can alter how the body stores fat, fluids, and other nutrients (metabolism). As many as 70% of people treated with corticosteroids for long periods reported some type of weight gain. A 2015 study discovered that around 22% of patients treated with prednisone for a year or more gained more than 10 kg (22 pounds).
  • Antipsychotics: Drugs like olanzapine and clozapine can also affect metabolism, and some research has linked nearly all antipsychotic drugs to some kind of weight increase.
  • Antihyperglycemics: These are diabetes drugs that increase insulin levels, changing the body’s fluid and fat retention. So, common diabetes drugs like insulin, sulfonylureas, and thiazolidinediones may cause weight gain.

Weight gain from these medications can occur in men or women, and anyone worried about it should talk to a doctor about the risks, benefits, and possible alternatives.

Certain medical conditions

Medical conditions might be the culprit behind weight gain. These conditions can also exacerbate the weight-related effects of a poor diet, sedentary lifestyle, or chronic stress.

  • Hypothyroidism (underactive thyroid): The thyroid is a gland responsible for regulating energy consumption (among other things), so when it doesn’t produce enough hormones, it can cause weight gain. It’s more common in women but can also affect men.
  • Kidney issues: According to some research, the incidence of end-stage kidney disease is 50% higher in men than women—and kidney disease can lead to fluid retention and weight gain.
  • Heart disease: The American Heart Association says rapid weight gain can be a sign of early-stage heart failure. Men have a higher prevalence of cardiovascular disease than women, and they’re more likely than women to experience heart attacks at earlier ages.
  • Cushing’s Disease: This is a disease that increases the body’s cortisol levels, which can lead to weight gain. Like hypothyroidism, Cushing’s occurs more often in women, but men are still at risk.

Should I be worried about weight gain in men?

If your weight fluctuates very slightly from day to day, it’s typically nothing to worry about. These very mild rises and falls are normal. However, “weight gain over a short time frame that is also accompanied by additional symptoms such as fatigue, shortness of breath, or swelling may indicate serious underlying medical conditions like heart failure, fluid retention, hormonal imbalances, or side effects from medications to name just a few,” Best says. “If the weight gain persists without explanation, seeing a primary care doctor is advisable.”

Slower weight gain isn’t as serious in the short term, although it may still require a trip to the doctor if it continues or doesn’t respond to diet and exercise. The doctor can diagnose any underlying chronic conditions and help develop a weight loss plan, whether it involves a healthy eating plan, an exercise routine, or specific weight loss medications.

Treatment is important since the CDC says obesity may contribute to the development of high blood pressure, high cholesterol, other heart disease, Type 2 diabetes, asthma, sleep apnea, joint problems like osteoarthritis, and gallbladder issues.

How is the cause of weight gain in men diagnosed?

Diagnosing weight gain itself isn’t exactly difficult. If the numbers on the scale are higher than before, it’s there. But diagnosing the cause of weight gain is trickier. That’s why visiting a doctor is key. They can assess the severity of your weight gain, help determine what might be causing it, and come up with an appropriate treatment plan.

At the office visit, the doctor will typically ask a few questions, particularly about medical history, symptoms, and lifestyle habits like eating habits, activity level, tobacco use, alcohol consumption, and more. They will also usually perform a physical examination and calculate body mass index (BMI) using your weight and height.

If the doctor suspects an underlying condition, they’ll generally need to confirm it by ordering other tests. For example, blood tests may help diagnose hypothyroidism, diabetes, metabolic syndrome, or Cushing’s Syndrome; urine tests may reveal kidney issues; and stress tests, electrocardiograms, CT scans, and other tests can confirm cardiovascular disease. These tests will often take place at a separate appointment and facility.

How to stop weight gain in men

The big question for many men who have excess weight is, “How can I lose it?” However, how weight gain is treated in men is usually multifaceted and depends on the cause.

“Metabolically active visceral fat is more common in men and poses greater health risks due to its active nature and association with deeper internal fat. In comparison, women are more likely to store subcutaneous fat, which lies just below the skin,” Dr. Chichak says. “These differences between the two sexes should be considered when devising personalized health plans that incorporate the different ways fat is distributed and affects health in men and women.”

If it stems from an underlying condition, treatments for weight gain in men should start with addressing that specific condition. For example, someone with hypothyroidism might need medications to replace thyroid hormone, someone with kidney disease might require medications or (if it’s severe) dialysis, and someone who has sleep apnea could need a CPAP machine.

Of course, an all-around healthy lifestyle can always help men get rid of weight gain, whether there’s an underlying condition or not. For men who have a higher rate of cardiovascular disease than pre-menopausal women, aerobic exercise and avoiding fatty and highly processed foods can be especially helpful. Sometimes, medications like GLP-1 receptor agonists or appetite suppressants might help as well.

Additionally, Dr. Chichak says, “Because of greater accretion of lean muscle mass, men are likely to respond better to exercise interventions, whereas women are likely to respond better to hormonal and specially crafted dietary methods.”

Most importantly, weight gain in men is treatable.

Whether it stems from an unhealthy diet, chronic stress, or a condition like hypothyroidism, there are ways to treat and reverse weight gain in men. Cases that arise from eating and exercise habits might respond with lifestyle changes and general wellness without medical intervention—but for weight gain that’s sudden, unexplained, or accompanied by other symptoms, it’s important to see a healthcare provider. Only they can determine the cause and create a treatment plan that will work for you. 

What’s next? Additional resources for weight gain in men

For more info and in-depth analysis, here are a few additional sources about weight gain in men.

Test and diagnostics

Treatments

Scientific studies and clinical trials