Weight Gain

Weight gain is when your weight increases due to changes in your body composition, like increased fat, muscle, or fluids. It is normal for people to experience weight changes throughout different stages of life, including puberty, pregnancy, and aging. Consult with your healthcare provider if you're concerned about weight gain.

This article discusses the symptoms, causes, and treatment for weight gain.

Low Section Of Woman Standing On Electronic Weight Scale On Floor

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Symptoms of Weight Gain

Symptoms of weight gain will vary depending on the underlying cause. The most common signs include:

  • Changes in fat distribution
  • Changes in weight
  • Increased waist circumference

Additional symptoms may occur if an underlying medical condition is causing the weight gain.

Causes of Weight Gain

There are many possible causes of weight gain, including genetics, stage of life, lifestyle factors, environmental factors, medical conditions, or medications. 

Genetics

While genetics do not directly cause weight gain, research suggests that some genetic factors may interact with the environment and influence your behaviors and metabolism, which can lead to weight gain.

Life Cycle

Our bodies change throughout our lives. Here are some examples:

  • Aging: As we get older, our metabolism slows down. After 30, our lean body mass decreases due to the loss of muscle and bone density, and body fat increases.
  • Menopause: Weight gain is typical for women in midlife. Menopause causes hormonal changes that may cause an increase in weight.
  • Pregnancy: Weight gain during pregnancy is necessary for the baby’s development. The recommended weight gain varies depending on the mother’s pre-pregnancy body mass index (BMI).
  • Puberty: Children gain an average of 6.5 pounds yearly from ages five through 12. As they enter puberty, they experience growth spurts. One and two years after puberty begins, girls and boys will experience peak growth rates in height, weight, and muscle mass.

Lifestyle Factors

Certain habits and lifestyle choices can impact weight.

  • Chronic dieting and weight cycling: While dieting can result in short-term weight loss, research shows that it is associated with long-term weight gain. This pattern of dieting, weight loss, and weight regain is known as weight cycling and is related to adverse physical and mental health outcomes. Research suggests that weight cycling may be more harmful than excess weight.
  • Sleep: Studies have found that sleep deprivation, the lack of sufficient sleep, is associated with weight gain due to the impact of sleep on appetite and energy regulation.
  • Smoking cessation: Nicotine suppresses appetite and speeds up metabolism, so when a person quits, they may experience a weight gain of five to 10 pounds. However, these changes are outweighed by the many health benefits of quitting.
  • Stress: When a person is under stress, they release a hormone called cortisol, which contributes to fat storage in the abdomen. It also increases appetite with a preference for foods high in calories.  

Environmental Conditions

Environmental factors such as access to nutritious foods, safe places to exercise, and exposure to environmental toxins affect weight.

  • Food deserts and food insecurity: Food deserts are areas where people lack access to healthy foods. Often these underserved communities have an overabundance of inexpensive, calorie-dense foods, which may influence their ability to have a healthful diet and affect their weight.
  • Environments that discourage physical activity: People often make choices based on their environment. Lack of access to safe spaces to exercise will impact physical activity levels.
  • Exposure to environmental toxins: Chemicals found in the environment, like bisphenol A (BPA), may disrupt the body’s hormonal system, impacting a person’s metabolism and contributing to the formation of fat cells.

Medical Conditions

Certain medical conditions are linked to weight gain.

  • Edema (swelling) is a build-up of excess fluid that can cause weight gain. The extra fluid could signify menstruation, heart or kidney failure, preeclampsia (high blood pressure while pregnant), or medication side effects.
  • Endocrine disorders impact the system responsible for hormonal balance and can be an underlying cause of weight gain.
  • Psychiatric conditions like binge eating disorder or depression can contribute to weight gain.

What Medication Can Cause Weight Gain?

Weight gain can be a side effect of several classes of medications, including:

  • Antidepressants are medications that treat depression and other mental health disorders. Examples include Prozac (fluoxetine), Zoloft (sertraline hydrochloride), and Parnate (tranylcypromine).
  • Antihyperglycemic is a class of medication used to lower blood sugar. Examples include Actos (Pioglitazone), Glucotrol (Glipizide), and Prandin (Repaglinide).
  • Antihypertensives are medications that lower blood pressure and are used to treat hypertension. Examples include Vasotec (Enalapril), Microzide (hydrochlorothiazide) and Aldactone (spironolactone).
  • Antipsychotics are medications that treat psychosis, a mental disorder that causes a person to lose touch with reality. Examples include Abilify (aripiprazole), Zyprexa (olanzapine), and Seroquel (quetiapine).
  • Birth control pills or oral contraceptives are taken daily to prevent pregnancy. Examples include YAZ (Drospirenone), Beyaz (Ethinylestradiol/Drospirenone/Levomefolic acid), and Loestrin 24 Fe (ethinyl estradiol, norethindrone and ferrous fumarate).
  • Corticosteroids are steroid hormones used to treat inflammatory, respiratory, and autoimmune disorders. Examples include Prednisone Intensol (prednisone).

How to Treat Weight Gain

The treatment will vary depending on the underlying cause of weight gain. Sudden or rapid weight gain may be a sign of fluid retention, an underlying medical condition, or a side effect of a medication. Working with a healthcare provider will help rule out any severe conditions. 

Lifestyle factors related to sleep, diet, and physical activity contribute to weight gain. Changing these habits may help treat weight gain. 

It's important to recognize that weight gain may be caused by factors not in your control, including genetics, aging, and environmental factors.

Are There Tests to Diagnose the Cause of Weight Gain?

A healthcare provider will assess your weight change and look for an underlying cause through various tests and examinations, including:

  • A physical exam
  • Blood tests
  • Calculating body mass index (BMI)
  • Measuring hormone levels
  • Medical history 
  • Nutritional assessment

When to See a Healthcare Provider

Weight gain, along with the symptoms below, requires medical attention:

  • Vision changes
  • Constipation
  • Excessive hunger along with palpitations, tremors, and sweating
  • Excessive, unintentional, unexplained weight gain 
  • Feeling colder than usual
  • Hair loss
  • Swollen feet accompanied by shortness of breath

Summary

Weight gain is a normal part of life as our bodies change over time. As we grow, such as in puberty and pregnancy, we will gain weight. Aging, lifestyle, environment, and medical conditions can contribute to weight gain. Some medical conditions and medications can cause weight gain as well.

It's important to understand the nuances of weight gain and recognize when to see a healthcare provider to rule out dangerous conditions.

A Word From Verywell

Weight gain can be a frustrating symptom, especially when unexplained. It’s important to remember that factors that may be out of your control can contribute to weight gain. Getting enough sleep, adopting a healthy diet, and getting enough physical activity are changes you can control that can positively affect your overall health.

Frequently Asked Questions

  • What causes weight gain?

    Various causes of weight gain include aging, genetic factors, lack of sleep, environmental factors, smoking cessation, medical conditions, and medications. 

  • How do I get rid of weight gain?

    Work with your healthcare provider to determine the underlying cause of weight gain. If it isn’t attributed to a health condition and doesn’t require medical attention, finding resources to address lifestyle factors may help. Remember that many factors, like aging, medical, and environmental conditions, may be out of your control.

  • Is weight gain a symptom of COVID-19?

    Weight gain is not a reported symptom of COVID-19 infection. However, a recent study showed that a rare effect of post-acute COVID-19 syndrome (PAC) was excessive eating, inability to feel satisfied or control appetite, eating large amounts of food, and weight gain. If you have post-acute COVID-19 symptoms, including an increase in appetite, food intake, and weight gain, speak to your healthcare provider. 

18 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Rebecca Valdez, MS, RDN
Rebecca Valdez is a registered dietitian nutritionist and nutrition communications consultant, passionate about food justice, equity, and sustainability.