The Hidden Cause Behind PCOS Weight Gain (And How to Combat It)

Polycystic Ovary Syndrome (PCOS) is one of the most common hormonal disorders affecting women, yet it remains widely misunderstood. Among its many symptoms, weight gain is one of the most frustrating and difficult to manage. Many women with PCOS find that traditional weight loss strategies—like cutting calories and increasing exercise—fail to deliver results. The reason? PCOS-related weight gain is not always related to a “bad” diet and a lack of exercise; it’s driven by complex hormonal imbalances, insulin resistance, and chronic inflammation.

Understanding these underlying factors is key to overcoming the challenges of PCOS weight gain. In this article, we’ll break down the hidden causes behind it and explore science-backed strategies to help you manage your weight more effectively.

What is PCOS?

Polycystic Ovary Syndrome (PCOS) is a common hormonal disorder affecting women of reproductive age. It disrupts the normal functioning of the ovaries, leading to a range of symptoms including irregular menstrual cycles, excessive hair growth, acne, and ovarian cysts. However, one of the most challenging aspects for many women is unexplained weight gain, particularly around the abdomen (1). 

PCOS is fundamentally linked to hormonal imbalances, particularly elevated levels of androgens (male hormones) and insulin. These imbalances interfere with the body's ability to regulate metabolism and fat storage. 

The 3 Main Culprits Behind PCOS and Weight Gain

While PCOS symptoms can vary from person to person, weight gain is one of the most frustrating and common challenges. But why is it so hard to lose weight with PCOS? The answer lies in three key culprits that disrupt your body's natural balance and make managing weight more complicated.

Insulin Resistance

Insulin is a hormone that regulates your blood sugar levels. If you suffer from insulin resistance, it means your cells have become less responsive to insulin, bringing about diabetes symptoms. This is especially prevalent in women with PCOS, affecting between 50% to 90% of those diagnosed. This resistance causes higher insulin levels, which can promote fat storage and make weight management more difficult. (2) 

But that's not all. High insulin levels can also interfere with another hormone called leptin, which regulates hunger. For women with PCOS, the constant overproduction of insulin triggers continuous leptin release (3). Over time, the body becomes desensitized to leptin's signals, leading to increased hunger and cravings, even when the body doesn’t need more food. Over time, this dysfunction raises the risk of developing type 2 diabetes, making insulin management crucial for long-term health.

Research indicates that women with the traditional PCOS phenotype—characterized by irregular periods, high androgen levels, and polycystic ovaries—often exhibit higher insulin levels and more pronounced insulin resistance. Interestingly, these metabolic issues persist regardless of differences in BMI when compared to other PCOS phenotypes, highlighting that weight gain isn't solely dependent on body size but is deeply rooted in hormonal and inflammatory pathways.

Hormonal Imbalances

Another key factor contributing to PCOS-related weight gain is hormonal imbalance, particularly elevated androgen levels. Androgens, often referred to as "male hormones," are naturally present in both men and women, but women with PCOS tend to produce them in excess. This hormonal disruption significantly impacts metabolism, fat distribution, and overall body composition (4). 

In women with PCOS, elevated androgens can:

• Slow down metabolism – Androgens influence the body’s ability to burn calories efficiently, meaning fewer calories are burned at rest, making it easier to gain weight and harder to lose it.

• Promote abdominal fat storage – Excess androgens encourage visceral fat accumulation, meaning fat is stored deep in the abdomen around vital organs rather than being evenly distributed. This type of fat is particularly concerning because it’s metabolically active (5) and increases the risk of insulin resistance, inflammation, and cardiovascular disease.

• Disrupt appetite regulation – Androgens can influence the way the brain processes hunger and satiety signals. Research suggests that hormonal imbalances in PCOS may alter the function of leptin and ghrelin, two key hormones responsible for regulating hunger cues.

Chronic Inflammation

Long-term, low-grade inflammation is increasingly recognized as a key factor in PCOS weight gain. Elevated glucose levels can trigger oxidative stress, leading to an overactive response from mononuclear cells (MNCs). Normally, these cells don't rely on fat, but in PCOS, they become significant contributors to inflammation.

MNC-derived macrophages are the primary producers of cytokines in large adipose (fat) tissues. These cytokines, in turn, encourage further production of inflammatory markers by fat cells, creating a cycle of chronic inflammation (6). This inflammatory response exacerbates insulin resistance, making it even harder for the body to regulate glucose and fat storage effectively. 

How to Stop PCOS Weight Gain

Losing weight with PCOS is challenging, but it’s not impossible. Unlike conventional weight loss advice, which often focuses solely on cutting calories and increasing cardio, managing PCOS-related weight gain requires targeting the root causes—insulin resistance, hormonal imbalances, and chronic inflammation. Here are three evidence-backed strategies to combat PCOS weight gain effectively.

Using Metformin

Metformin, a medication commonly used to treat type 2 diabetes, has been widely studied for its benefits in managing PCOS. Research has shown that metformin can:

• Reduce serum androgen levels, helping to rebalance hormones and mitigate symptoms like acne, excess hair growth, and weight gain.

• Improve insulin sensitivity, making the body more responsive to insulin and reducing the likelihood of excess sugar being stored as fat.

• Restore menstrual regularity and support ovulation, making it a valuable treatment option for PCOS-related infertility.

A study published in Frontiers in Endocrinology highlights that metformin significantly reduces insulin resistance and helps lower BMI in women with PCOS (7). By improving how the body processes sugar and regulates insulin, metformin can make it easier to lose weight while also addressing some of the underlying metabolic dysfunctions of PCOS.

However, while metformin can be effective, it’s not a magic pill. Many women experience side effects such as nausea and gastrointestinal discomfort. It works best when combined with lifestyle changes, such as a balanced diet and the right type of exercise.

Doing Exercise 

Exercise is crucial for improving insulin sensitivity and promoting sustainable weight loss in women with PCOS. However, not all workouts are equally beneficial. Since many women with PCOS have higher cortisol levels (stress hormone), engaging in too much high-intensity exercise can worsen hormonal imbalances (8). HIIT workouts, excessive running, or long-duration cardio can spike cortisol, making weight loss even harder.

Instead, focus on workouts that enhance insulin sensitivity and muscle metabolism without overstressing the body:

• Strength training (Without high intensity) – Lifting weights forces muscles to burn stored glucose, improving insulin sensitivity and reducing fat storage. Plus, the more muscle you build, the more glucose your body will naturally burn throughout the day.

• Swimming – A low-impact, full-body workout that promotes cardiovascular health without triggering excessive cortisol spikes.

• Pilates & Yoga – These exercises help lower stress hormones while improving flexibility, muscle tone, and insulin regulation. Yoga has even been shown to reduce testosterone levels in women with PCOS.

By focusing on strength-based and low-impact workouts, you can help your body manage insulin better, reduce inflammation, and promote fat loss in a way that supports long-term hormonal balance.

Trying Myo-Inositol

If metformin isn’t an option or causes intolerable side effects, inositol is a powerful natural alternative that can significantly improve PCOS symptoms. Many women have reported life-changing benefits from taking inositol, particularly in the form of myo-inositol (9) or a combined myo- and D-chiro-inositol supplement. Some of the key benefits include:

• Improved sleep and reduced inflammation: Many PCOS sufferers notice less joint pain, swelling, and skin issues like rosacea after just a few weeks of use.

• Better appetite control: Inositol reduces sugar cravings and overeating tendencies, helping women naturally eat less without feeling deprived.

• Enhanced insulin sensitivity: Similar to metformin, inositol helps muscle cells absorb glucose more efficiently, preventing excess sugar from being stored as fat.

The recommended dosage is 4 grams of myo-inositol per day, often split into two doses. Many women report feeling noticeable effects within days, such as:

• Reduced bloating and improved digestion

• Fewer sugar cravings and more stable energy levels

• Less water retention and swelling

If you’re struggling with PCOS-related weight gain, inositol can be a game-changer, particularly when combined with a balanced diet and strength-based workouts.

Improve Your Diet to Address PCOS’ Symptoms

When it comes to losing weight with PCOS, diet plays a critical role. However, the key isn’t just cutting calories: you also need to learn about balancing blood sugar, stabilizing insulin levels, and reducing inflammation. The right food choices can help optimize hormones and make weight loss much easier.

Don’t Eliminate Carbs

Carbohydrates are often viewed as a primary challenge for women with PCOS due to their impact on insulin levels. However, eliminating them is neither necessary nor beneficial. Instead, it is important to modify the way carbohydrates are consumed to prevent rapid blood sugar spikes.

• Pair carbohydrates with fiber, protein, or healthy fats to slow digestion and promote steady blood sugar levels. For instance, instead of eating a plain bagel, try topping it with avocado and eggs, or pair your apple with a handful of almonds.

• Consume protein and fats first during meals before eating carbohydrates to help regulate insulin response. For example, when having a stir-fry meal, eat the chicken and vegetables first, then incorporate the rice or noodles toward the end of your meal.

• Prioritize complex carbohydrates such as whole grains, legumes, and fiber-rich vegetables rather than refined and processed options like white bread or pastries.

Reducing Added Sugars

Excess sugar consumption contributes to insulin resistance, systemic inflammation, and weight gain (10). Many processed foods contain high levels of added sugars or seemingly healthy sweeteners, which can be difficult to detect without carefully reading ingredient labels.

• Minimize intake of processed sweets such as candy, cakes, and sugar-laden beverages.

• Opt for naturally sweet alternatives like fruit or dark chocolate in moderation.

• Replace sugary drinks with water or unsweetened beverages to reduce unnecessary calorie intake.

Managing Sodium Intake

While sodium does not directly contribute to weight gain, excessive intake can lead to water retention and bloating, which may exacerbate discomfort and inflammation. Since the majority of dietary sodium comes from processed and restaurant foods, reducing reliance on prepackaged meals can be beneficial.

• Choose low-sodium options when purchasing packaged foods.

• Enhance flavor with herbs and spices instead of relying on added salt.

• Maintain adequate hydration to support the body’s ability to regulate sodium balance.

Is it hard to lose weight with polycystic ovarian syndrome?

Weight loss with PCOS presents unique challenges due to hormonal imbalances, insulin resistance, and metabolic dysfunctions we mentioned above. These factors can make traditional weight loss methods less effective, which means a targeted approach that focuses on blood sugar regulation, inflammation reduction, and hormone balance can lead to successful and sustainable results. 

Plus, the type of exercise to be done is not the same as in traditional weight gain. By adopting a balanced diet that prioritizes nutrient-dense foods, managing insulin levels, and making lifestyle modifications, women with PCOS can improve their metabolic health and achieve better weight management outcomes.

Can I have PCOS without weight gain?

Yes, it is possible to have PCOS without experiencing weight gain, a condition known as lean PCOS (11). Many people associate PCOS with obesity but lean women can still experience the same hormonal imbalances, such as elevated androgens and insulin resistance, despite having a normal BMI. Symptoms of lean PCOS often include irregular menstrual cycles, acne, excess hair growth, and difficulties with ovulation. Though these women may not show obvious metabolic dysfunction, research suggests that insulin resistance and inflammation can still be present, increasing the risk of type 2 diabetes and cardiovascular disease over time.