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What Can Cause Sudden Weight Gain In Women?

Jan 22, 2023
What Can Cause Sudden Weight Gain In Women?

When women go through transitions involving hormonal swings, such as the monthly menstrual cycle, pregnancy, lactation, and perimenopause, sudden or unexpected weight gain is not unusual. Compared to men, women experience more jarring hormonal changes. Of course, stress, anxiety, and the natural aging process are all significant contributors to weight gain, as are poor diet and inactivity.

Both men and women may struggle with weight gain as they age, but the distribution of excess pounds and the contributing factors vary. There are definitely aging differences depending on sex and gender. For example, fat may be stored under the skin or around visceral organs. Visceral (abdominal) fat is more dangerous to your health. Men tend to have more visceral fat, while women have more subcutaneous fat.

Declining sex hormones set the stage for weight gain, as most people experience a steady gain in fat mass and a decrease in muscle mass as sex hormones decline. Of course, you do not need to accept this as a fact of life. A healthy diet and prioritizing time for resistance exercise can combat the effects of aging.

Symptoms Of Sudden Weight Gain In Women

The average woman gains about one to two pounds each year. In a study that followed over 120,000 U.S. men and women who were free from disease and did not have obesity, the average weight gain was about 3.5 pounds over a four-year period, with a range of 4 pounds lost to 12 pounds gained. Interestingly, consumption of certain foods was associated with more weight gain, including potato chips, potatoes, sugar-sweetened beverages, unprocessed meats, and processed meats.1

Researchers also found that an increase in physical activity was associated with weight gain but it stabilized over time. This is not uncommon, as your body composition changes with exercise, especially muscle-building resistance exercise. Many people find that their appetite increases after aerobic exercise, with the calories consumed often much higher than the calories burned.

While it’s normal to gain weight with age, it is important to stay healthy as you age. If you are experiencing sudden weight gain or have other symptoms, call your doctor for a checkup to rule out an underlying cause.

Causes Of Sudden Weight Gain Among Women

Genetic predisposition, biology, sleep, diet, muscle mass, and hormones all affect your weight and how easily you gain weight. Each phase of a woman’s reproductive life is associated with weight gain.

Most girls can remember gaining 15 to 20 pounds in a single year as their bodies changed and they entered puberty. Sudden increases in sex hormones, lengthened bones and added body fat.

Fluxes in estrogen and progesterone can cause temporary weight gain right before your period. Many women notice that their appetite surges in the second half of their cycle when progesterone is dominant. Estrogen is dominant in the first half of your cycle, and it suppresses appetite.2 Of course, cravings also increase in the second half of your cycle, making it difficult to resist sweet and salty treats.3

Weight gain can also be an early sign of pregnancy. You should rule out this one cause of weight gain before considering other causes.   

Menopause is defined as not having a period for 12 consecutive months. It is associated with weight gain. Most women gain about 5 pounds as they pass through this transition. In one study, researchers found that women in their 50s and 60s gain an average of 1.5 pounds per year.4 Decreased physical activity and muscle mass may also contribute to weight gain.

Effects Of Medications

Some medications cause weight gain as a side effect. They may stimulate your appetite, cause water retention, or affect your body’s metabolic rate. Medications that cause side effects such as fatigue or weakness can cause weight gain because they decrease your ability and motivation to exercise.

Medications that may cause weight gain in some people:

  • Antidepressants: Selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants can cause weight gain in some individuals.
  • Antipsychotics: Haldol, clozapine, risperidone, lithium, and other medications used to treat schizophrenia and bipolar disorder can cause weight gain.
  • Corticosteroids: Prednisone and other steroids cause weight gain by stimulating your appetite and causing fluid retention.
  • Diabetes medications: Insulin, thiazolidinedione, and sulfonylureas can cause weight gain.
  • Contraceptives: some contraceptives may cause weight gain, though the low-dose ones that are available now are less likely to than the older versions.
  • Blood pressure medications: Beta-blockers such as propranolol and metoprolol.
  • Anticonvulsants: Medications used to treat seizures, such as valproate and carbamazepine.
healthy fruits and vegetables

Changes In Diet

Dietary changes can creep up on you. One minute you are eating healthy sources of fats and proteins and consuming lots of fruits and vegetables. Then you go through a stressful period in life when you have little time and patience, and fast food becomes dinner every night.

Whether you are consuming too many “convenience foods” or choosing foods that are on the “what not to eat when you are over 50,” the pounds can add up before you know it. Highly processed foods taste great, but don’t really fill you up, leaving you with hunger and cravings for more.

In one study, researchers tracked calorie consumption by 20 hospitalized adults who ate an ultra-processed diet for 14 days, followed by an unprocessed diet. The two diets contained the same calories, sugar, fat, fiber, and macronutrients. The study participants ate 500 calories more each day. They consumed the ultra-processed diet and gained weight.5

Sometimes weight gain is not the result of dietary changes but is due to an increase in food consumption. There are many reasons for increased appetite in women. One of the most common is hormonal imbalance, whether estrogen, progesterone, steroids, or thyroid hormone.

Changes In Activity Level

While diet and exercise both contribute to metabolism and weight gain, Diet is the more important of the two. Eating a high-calorie diet makes it almost impossible to burn enough calories and prevent weight gain by exercising alone.  

With that said, exercise can boost your metabolic rate, especially if you build muscle. If you can burn an extra 200 to 300 calories a day by incorporating physical activity into your day and keeping your calorie intake the same, you can get a slow and steady weight loss.

In a study that tracked the activity levels of overweight adults, the average person sat about 6 hours per day. Most of this sedentary time was spent doing work-related tasks or watching television.6 If you have a lack of energy and want to increase it, here are some tips to get your metabolic fires burning again:

  • Incorporate short bursts of exercise into your day
  • Eat lunch away from your desk after going for a quick walk
  • Set limits on technology, so you have more free time to get moving
  • Get plenty of sleep
  • Identify and manage stressors

Stress, Anxiety, Or Depression

Stress, anxiety, and depression are linked, though the connections are not well understood. Stress can contribute to changes in dietary intake which can lead to weight gain. Emotional eating and eating as a stress response can both cause weight gain.

In one study in which researchers followed U.S. adults for nine years, having job-related demands, difficulty paying bills, or depression or generalized anxiety disorder were all associated with having a higher body mass index (BMI).7

Some people have just the opposite response to stress, depression, and anxiety. They eat less when stressed. If you are trying to manage your weight, consider your cognitive health as a potential cause of weight gain.  

Not Sleeping Well

Several studies have shown an association between poor sleep and weight gain. Sleep is an active process. When you are sleeping, your body repairs damaged tissues, removes wastes, and regulates hormones that control appetite and metabolism.

When you do not get enough sleep, ghrelin, a hormone that stimulates appetite, increases. Nonrestorative sleep also causes a decrease in leptin, the hormone that suppresses appetite and tells your brain you are satisfied. Lack of sleep causes increased appetite, especially for high-fat and high-carbohydrate foods.8

Lack of sleep causes fatigue which makes it harder to exercise and make healthy dietary choices. About 40% of American adults currently report getting less than 7 hours of sleep each night.9

women in bed sleeping with alarm clock

Menopause Or Perimenopause

Most women associate menopause with weight gain because the phenomenon is so widespread. It makes sense that rapidly plummeting sex hormones (hormonal aging) would trigger changes in metabolism and appetite that cause weight gain.

Body composition changes associated with menopause include an increase in weight and total body fat, an increase in abdominal fat, and a decrease in muscle. Aging, a decrease in estrogen and androgens, and secondary hormone-related conditions, such as thyroid disease, may all contribute to weight gain during menopause. Sedentary behaviors, poor dietary choices, excessive calorie consumption, smoking, alcohol consumption, and low vitamin D may also contribute.

If you are experiencing weight gain during perimenopause, talk with your doctor to rule out thyroid disease and other medical conditions that may cause weight gain. It is also important to talk about your risk factors for obesity and discuss whether medical or lifestyle changes can help decrease this risk.

Medical Conditions

Some underlying medical conditions are also associated with weight gain, including:

  • Hypothyroidism: the thyroid gland controls metabolic rate. When your thyroid levels are too low, your metabolism slows, which makes it much easier to gain weight. Minor differences in thyroid function can cause 10 to 12 pounds of weight gain due to decreased metabolic rate and excessive water bound to body tissues.10
  • Polycystic ovary syndrome (PCOS): This common endocrine condition causes infertility, irregular menstrual cycles, excessive hair growth, severe acne, and thickened patches of velvety, darkened skin along the neck and axilla. PCOS increases insulin resistance which can increase androgen production and cause weight gain.11
  • Diabetes or prediabetes: The relationship between type 2 diabetes, insulin resistance, and obesity are complicated. Gaining weight increases your risk for insulin resistance and type 2 diabetes. Some medications used to treat type 2 diabetes can cause weight gain.

Sudden Weight Gain From Birth Control?

Many women attribute sudden weight gain to starting or stopping contraceptives. Long ago, combination hormonal contraceptives had much higher doses of estrogen and progesterone and were more likely to cause weight gain. This is much less likely now, but it does occur.12

The most likely causes of weight gain associated with birth control pills are:

  • Fluid retention: This is usually temporary and can be improved with good nutrition and hydration.
  • Bloating: This is a feeling of fullness or swelling in the abdomen. Hormonal changes, overeating, and changes in gastrointestinal motility can cause it.
  • Increased appetite or other diet changes: You can be excessively hungry for many reasons. Some examples are poor sleep, stress, low protein or low-fiber diets, and dehydration.
  • Mood swings causing stress or anxiety: Hormones flux when you start or stop hormonal contraceptives. This can cause mood swings which can be worsened by dieting. Read more about how to deal with mood swings from dieting.  
Birth control pills and devices

Treatment For Sudden Weight Gain

Sudden weight gain can be problematic, especially if you cannot identify a cause. See your doctor if you suspect an underlying medical condition. Otherwise, here are some tried-and-true treatments for sudden weight gain:

  • Exercise regularly: Make exercise a part of your day, especially if you are trying to counteract muscle loss as an older adult. Body weight exercises to increase muscle mass and walking are great exercises for older adults.  
  • Eat a healthy diet with whole foods (;
  • Regulate appetite: Highly processed foods are addicting and leave you wanting more. Add more whole foods to your diet to feel full and to supply your body with the fuel it needs to function optimally.
  • Manage stress: Identify stressors in your life and look for ways to reduce anxiety and manage stress. Engaging in hobbies, meditating, exercising, and spending time in nature can all help ease stress and anxiety.
  • Naturally regulate hormones: Naturally regulate your hormones by choosing a healthy diet, prioritizing exercise and restful sleep, and trying supplements that fill any nutritional gaps you may have.

In many cases, sudden weight gain is because of lifestyle changes that creep up on us. Convenience foods, sedentary behavior, spending time with technology instead of sleeping, and not managing stress can all contribute to sudden weight gain. Commonly, weight gain can be managed with lifestyle changes or treatment.

While we strive to always provide accurate, current, and safe advice in all of our articles and guides, it’s important to stress that they are no substitute for medical advice from a doctor or healthcare provider. You should always consult a practicing professional who can diagnose your specific case. The content we’ve included in this guide is merely meant to be informational and does not constitute medical advice.

What Can Cause Sudden Weight Gain In Women?

Leann Poston, M.D.

Dr. Leann Poston is a licensed physician in the state of Ohio who holds an M.B.A. and an M. Ed. She is a full-time medical communications writer and educator who writes and researches for Invigor Medical. Dr. Poston lives in the Midwest with her family. She enjoys traveling and hiking. She is an avid technology aficionado and loves trying new things.


  • Mozaffarian D, Hao T, Rimm EB, Willett WC, Hu FB. Changes in diet and lifestyle and long-term weight gain in women and men. N Engl J Med. Jun 23 2011;364(25):2392-404. doi:10.1056/NEJMoa1014296
  • Hirschberg AL. Sex hormones, appetite and eating behaviour in women. Maturitas. 2012;71(3):248-256. doi:10.1016/j.maturitas.2011.12.016
  • Gorczyca AM, Sjaarda LA, Mitchell EM, et al. Changes in macronutrient, micronutrient, and food group intakes throughout the menstrual cycle in healthy, premenopausal women. Eur J Nutr. Apr 2016;55(3):1181-8. doi:10.1007/s00394-015-0931-0
  • Kapoor E, Collazo-Clavell ML, Faubion SS. Weight Gain in Women at Midlife: A Concise Review of the Pathophysiology and Strategies for Management. Mayo Clinic Proceedings. 2017;92(10):1552-1558. doi:10.1016/j.mayocp.2017.08.004
  • Hall KD, Ayuketah A, Brychta R, et al. Ultra-Processed Diets Cause Excess Calorie Intake and Weight Gain: An Inpatient Randomized Controlled Trial of Ad Libitum Food Intake. Cell Metab. Jul 2 2019;30(1):67-77.e3. doi:10.1016/j.cmet.2019.05.008
  • Martínez-Ramos E, Beltran AM, Martín-Borràs C, et al. Patterns of sedentary behavior in overweight and moderately obese users of the Catalan primary-health care system. PLoS One. 2018;13(1):e0190750. doi:10.1371/journal.pone.0190750
  • Block JP, He Y, Zaslavsky AM, Ding L, Ayanian JZ. Psychosocial Stress and Change in Weight Among US Adults. American Journal of Epidemiology. 2009;170(2):181-192. doi:10.1093/aje/kwp104
  • Parvin R. Are We Sleeping Enough? Journal of Enam Medical College. 2017;7(3):120-121.
  • Laurberg P, Knudsen N, Andersen S, Carlé A, Pedersen IB, Karmisholt J. Thyroid function and obesity. Eur Thyroid J. Oct 2012;1(3):159-67. doi:10.1159/000342994
  • Glueck CJ, Goldenberg N. Characteristics of obesity in polycystic ovary syndrome: Etiology, treatment, and genetics. Metabolism. Mar 2019;92:108-120. doi:10.1016/j.metabol.2018.11.002
  • Gallo MF, Lopez LM, Grimes DA, Schulz KF, Helmerhorst FM. Combination contraceptives: effects on weight. Cochrane Database Syst Rev. Jan 25 2006;(1):Cd003987. doi:10.1002/14651858.CD003987.pub2


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