Jun 22, 2023 • 8 min read

PCOS Weight Gain: Why It Happens & How to Help  

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Polycystic ovary syndrome (PCOS) is a complex metabolic disorder affecting 6% to 12% of women in their reproductive years in the United States. Common symptoms include excessive hair growth on the face (hirsutism), insulin resistance, skipped or absent periods, acne, infertility, and obesity. 

Research shows that as many as 88% of women with PCOS are also obese or overweight. The factors leading to PCOS and obesity are similar, so it makes sense to see the same outcomes among susceptible women. 

But does PCOS cause weight gain? Or is it the other way around? Evidence suggests that the primary metabolic features seen in PCOS—excess male hormones and insulin resistance—do contribute to weight gain among affected women. 

This guide goes over why weight gain happens with PCOS and some ways to help reduce both weight gain and the most common symptoms of PCOS. 

How insulin resistance from PCOS causes weight gain

There is no single factor causing either PCOS or obesity, yet it is clear that insulin resistance is a common pathway toward obesity and PCOS symptoms. 

Insulin resistance means your ability to put glucose sugar into your cells is impaired. This results in higher circulating blood sugar which can lead to weight gain.

Some factors we understand through research are these:

  • Genetic factors. We don’t know all the genetic factors leading to PCOS inheritance; however, animal models show that certain gene mutations mean you are more likely to get PCOS regardless of other circumstances. Insulin resistance is heritable from your parents. 
  • Epigenetic factors. Epigenetics involve changes in your DNA (genetics) that occur in early life that affect your health later. With PCOS, high levels of androgens (male hormones) in pregnant women lead to PCOS in their babies, even if the babies do not grow up to be obese. 
  • Obesogenic environment. An obesogenic environment is one where obesity is likely. Eating too many calories and exercising too little are both things that contribute to obesity. Having insulin resistance also leads to obesity because you cannot use your glucose fuel and instead store those excess calories as fat. 

The common denominator in both obesity and PCOS is insulin resistance. Once a female child has a tendency toward insulin resistance because of genetic and epigenetic factors, the issue itself causes more fat deposition and increasing obesity. 

Other reasons PCOS can cause weight gain

It appears that insulin resistance as part of PCOS is the major contributor to the development of obesity; however, there are other causes that are part of increased fat deposition in those who have PCOS:

  • Hormonal imbalances. High androgen (male hormones) levels in men cause increased muscle bulk. Among women with PCOS, this is not the case. Instead, the imbalance means that fat deposits around the middle, leading to what is commonly called a PCOS belly
  • Metabolic issues. Among those with PCOS, obesity itself is a metabolic issue contributing to even more fat deposition. Fatty tissue causes the release of inflammatory cytokines that cause fatigue, poor exercise tolerance, and added weight gain. 
  • Poor appetite regulation. Your appetite is regulated by the balance of hormones regulating hunger and satiety. The ghrelin hormone from an empty stomach leads to hunger, while the leptin hormone found in fat cells inhibits it. Some evidence suggests that obese individuals are relatively insensitive to the leptin hormone, triggering hunger despite having excess body fat. 
  • Hypothyroidism. Hypothyroidism is a common autoimmune disease in women of reproductive age.  When low thyroid function is present, your metabolism is poor and you gain weight even with a low caloric intake. 
  • Poor sleep. Poor sleep contributes to issues with appetite regulation and metabolism that together promote increased food intake in the presence of reduced metabolic activity in the cells. Weight gain happens more easily when you get less than the recommended seven to nine hours of sleep per night. 
  • Stress & anxiety. Stress and anxiety cause elevated cortisol levels. High cortisol levels contribute to the release of blood sugar and the functional equivalent of insulin resistance. High blood sugar causes high insulin levels and results in sugar energy being stored as fat. 
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Risks of weight gain from PCOS

When PCOS leads to weight gain, it isn’t just excess body weight that happens. High levels of body fat cause a series of secondary complications that can have far-reaching adverse effects on your health and longevity:

  • Type 2 diabetes. Weight gain and, in particular, a gain in body fat causes further insulin resistance in self-perpetuating ways. Eventually, the scale tips toward diabetes mellitus and its known complications, including diabetic eye, kidney, and nerve disease. 
  • Heart disease & high blood pressure. Obesity, along with high cholesterol, higher androgen levels, inflammation, high blood pressure, and insulin resistance, causes accelerated blood vessel disease and a greater risk of blood clots to the extremities, heart, and brain. The pattern of blood clots in any of these regions is collectively known as “heart disease.” 
  • Stroke. A stroke is a blood clot in the arteries to the brain leading to paralysis, speech, and mobility issues. You can also get a stroke when obesity leads to high blood pressure. Hemorrhagic strokes are caused by weakened blood vessels in the brain under the influence of very high blood sugar. 
  • Sleep apnea. Excess body fat often means the airway is narrowed by fatty tissue in the throat and mouth. When you sleep, your airway naturally collapses. In sleep apnea, the airway sometimes closes, leading to breathing attempts that do not bring in air. Sleep apnea contributes to poor sleep, daytime sedation, and obesity. 
  • Mental health issues. PCOS and insulin resistance contribute to the low availability of brain nutrients. For this and other reasons, you are more likely to have depression and anxiety, most of which is biological and neurological in origin. 
  • Fertility issues. High levels of male hormones along with ovarian cysts cause low AMH levels in the ovaries. Eggs do not mature fully, leading to an inability to ovulate and a higher risk of female infertility. 
  • Endometrial cancer. Normal periods involve the shedding of the endometrial (inner) lining of the uterus. When you don’t ovulate, the lining doesn’t shed completely. Over time, this overstimulation of the endometrial lining can contribute to the development of cancer in this tissue. 
  • Pregnancy complications. Women with PCOS who do become pregnant have a higher risk of several pregnancy complications, including preterm birth, miscarriage, stillbirth, small babies at term, gestational diabetes, preeclampsia, and cesarean section. 
  • NAFLD. NAFLD means “non-alcoholic fatty liver disease.” It is a common cause of excess fat buildup in the liver. This is a common complication of the lipid abnormalities found in PCOS; it may lead to liver failure or liver cancer in rare cases. 

How to lose weight with PCOS

Is it possible to lose weight easily with PCOS? Not at all.

Insulin resistance makes it hard to lose weight with PCOS, even when you get plenty of exercise and watch your caloric intake. The good news is that even a small weight loss of 5% to 10% of your total body weight can improve insulin resistance and symptoms of PCOS. 

If you work hard to lose around 10 pounds or so, the improvement in symptoms and energy levels can contribute to an accelerated weight loss beyond the first 10 pounds, particularly if insulin resistance and inflammation are reduced.

You may also want to talk to your doctor about medications for weight loss with PCOS.

Here are some ways you can lose weight in healthy ways:

  • Eat well. A good PCOS diet includes non-starchy vegetables, fruits, whole grains, lean meats, and healthy fats. Eat homemade food and avoid sugar, starchy vegetables, processed rice, and other processed meals. The goal is to reduce insulin release and prevent sugar spikes. There is some evidence that the keto diet can be beneficial for people with PCOS.
  • Exercise regularly. The recommended heart-healthy exercise program is 150 minutes of vigorous exercise per week. If fatigue, obesity, or other factors preclude this recommendation, do not decide to avoid exercise altogether. Instead, do the type of exercise you can do in the time that makes sense for you now. There is a good chance that your exercise tolerance will increase over time. 
  • Reduce stressors. Stress causes an increase in plasma cortisol levels. High cortisol makes it harder to lose weight by causing sugar energy to become fat. You may find that exercise alone makes it easier to tolerate stress. 
  • Sleep seven to nine hours nightly. Remember that sleep affects your appetite and metabolism. More sleep means that your appetite should be reduced enough to promote better weight loss. 
  • Consider supplementation. There are some vitamins and supplements that may help with PCOS weight loss. As always, it’s important to talk to your doctor or healthcare provider before starting any supplements and medication.

>> Find a PCOS Nutritionist That Accepts Your Insurance

Other symptoms & complications of PCOS

PCOS is much more than having cysts on your ovaries. There are symptoms that make it challenging to have this disorder apart from the issues just discussed:

  • Missed or absent periods. The higher levels of male hormones lead to an inability to ovulate. This can look different for you than it does for other individuals. You could have irregular periods, frequently skipped periods, or completely absent menses. 
  • Increase body and facial hair. High levels of male hormones contribute to the development of male patterns of hair, including facial hair and increased body hair. 
  • Acne. Acne comes from an imbalance in reproductive hormones and androgen excess. Your skin may be oily, and you could have more acne. 
  • Voice changes. The presence of male hormones could trigger the thickening of the vocal cords and a lower voice. Even if you are treated and the hormone levels are balanced, your voice may continue to be lower than it once was. 
  • High cholesterol. The metabolic dysfunction in PCOS includes higher cholesterol and triglyceride levels. Some of these extra fats are deposited in the liver. Cholesterol also causes plaque buildup in the arteries; plaque can contribute to heart disease. 
  • Infertility.  There are many contributing factors in PCOS that cause infertility. While you can still get pregnant, the combination of cysts on the ovaries and excess male hormones leads to ovarian dysfunction and infertility. Side note: you can learn how to develop a diet that can help with PCOS fertility issues here.

How a nutritionist can help with PCOS weight gain

It is possible to reverse the weight gain seen in PCOS; however, it may be difficult to do by yourself. The good news is that you do not have to do this alone. A PCOS nutritionist can make all the difference in the world, particularly when dealing with the complexities of this disease. 

PCOS nutritionists are fully trained in clinical nutrition and in the metabolic issues found in PCOS. They can evaluate your current situation and guide you with proven strategies unique to your situation. 

Be prepared to talk about your current diet and symptoms. The PCOS nutritionist can then provide personalized recommendations to jump-start your weight loss and help you maintain any weight loss you have already achieved. 

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Christine Traxler MD is a family physician, lifelong writer, and author with a special interest in mental health, women’s healthcare, and the physical after-effects of psychological trauma. As a contributing writer and editor for numerous organizations, she brings a holistic focus to her work that emphasizes healing and wellness through daily self-care, connecting with others, and setting stepwise goals toward achieving more balanced and authentic lives.