Polycystic ovary syndrome (PCOS) affects up to 15–20% of women of reproductive age. It occurs when levels of certain hormones are out of balance, leading to the growth of fluid-filled sacs on the ovaries.
Side effects include irregular or absent periods, hair loss, excess hair growth, acne, weight gain, depression and fertility problems.
PCOS is also associated with a higher risk of type 2 diabetes, heart disease and obesity. Unfortunately, there is no cure for PCOS. However, one of the first-line treatments is diet and lifestyle changes.
In fact, in overweight women, as little as a 5% weight loss can restore irregular periods and boost ovulation.
Below are 7 evidence-based dietary tips that can relieve symptoms and boost weight loss in women with PCOS.
1. Try a Low-GI Diet
Insulin is a hormone that transports sugar from your blood into your cells for energy or storage.
Women with PCOS are often insulin resistant, meaning their cells don’t use insulin as readily as they should. This increases insulin and blood sugar levels, causing unpleasant symptoms.
However, a low-glycemic index diet can help keep insulin levels stable.
The glycemic index (GI) is a measure of how quickly a food raises blood sugar levels. A low-GI diet consists of eating foods that raise blood sugar levels slowly, which helps prevent insulin spikes.
The low-GI diet usually consists of eating whole fruits and vegetables, whole grains, lean protein and healthy fats. It also involves avoiding most processed or refined carbs, including sugary foods and drinks.
A low-GI diet can have many health benefits, especially for women who have PCOS-driven insulin resistance.
2. Don’t Skimp on Breakfast
Women with PCOS are encouraged to eat regular meals.
For normal-weight women with PCOS, eating almost half of their daily calories at breakfast reduced insulin levels by 8% and testosterone levels by 50% over 90 days.
In addition, these women ovulated 30% more often than women who ate a smaller breakfast and larger dinner, suggesting improved fertility.
However, it’s important to note that increasing the size of your breakfast without reducing the size of your evening meal is likely to lead to weight gain.
3. Eat Enough Healthy Fats
An adequate supply of healthy fats, including omega-3 fatty acids, has been shown to help balance your hormones and improve insulin levels in women with PCOS.
Some healthy fats include oily fish, avocados, olive oil and unsalted nuts and seeds.
Even without omega-3 supplements, adequate intake of healthy fats may also improve insulin resistance.
However, to avoid weight gain, try to replace unhealthy fats from processed or fried foods with healthy fats, rather than adding extra into your diet.
4. Cut Down on Carbs
Reducing your carb intake may improve the hormonal imbalance linked to PCOS and boost weight loss in women with PCOS.
Insulin is produced as carbs are converted into glucose in the body.
These benefits aren’t just limited to a better hormone balance. A low-carb diet has also been shown to help boost weight loss.
Compared to a standard diet, a low-carb diet can lead to an additional 1–5% weight loss in women with PCOS.
The slightly greater weight loss associated with a low-carb diet may be due to the naturally higher protein and fat intake that it promotes. This can help reduce blood sugar levels, cravings and appetite, all while improving feelings of fullness.
Alternatively, it may be that by reducing carbs, you naturally tend to follow a lower-GI diet, which can improve the hormonal effects of PCOS.
5. Eat Plenty of Lean Protein
Androgens, such as testosterone, are male sex hormones. While women have androgens, levels of these hormones tend to be higher than normal in women with PCOS.
This partly explains some of the unpleasant side effects of PCOS, such as excess facial hair, a deeper voice and irregular periods.
Compared to high-carb foods, high-protein foods do not cause great increases in insulin levels.
A high protein intake also suppresses ghrelin, a hunger hormone, for much longer than carbohydrates.
As a result, a high-protein diet is likely to be much more filling and reduce insulin levels, both of which can have positive effects on PCOS symptoms.
Be sure to include plenty of healthy protein sources in your diet, such as lean meat, fish, eggs, beans and some dairy products.
6. Stay Active
Regular exercise has many health benefits, especially for women with PCOS.
In overweight and obese women with PCOS, body composition improved when exercise was combined with a weight loss diet.
In fact, just three hours of exercise per week has been shown to improve insulin sensitivity and reduce belly fat in women with PCOS.
This is important because chronic inflammation tends to be more common in women with PCOS and is linked to insulin resistance.
7. Some Supplements May Be Helpful
Studies show that certain supplements may help ease the symptoms of PCOS, especially in women who have low levels of those nutrients. For example, vitamin D deficiency is associated with some of the negative side effects of PCOS like obesity, insulin resistance and reduced ovulation.
Therefore, it’s often recommended that women with PCOS who are deficient in this vitamin take vitamin D supplements.
However, it has not been proven that vitamin D supplements will reduce these negative side effects. Therefore, more research is needed.
Interestingly, vitamin D deficiency is one of the most common deficiencies worldwide. Its main source is the sun. If your levels of vitamin D are low and you don’t get much sun exposure, most health professionals will recommend taking a supplement.
Another nutrient that may help improve PCOS symptoms is chromium, an essential mineral that helps boost the action of insulin.
Chromium deficiency is a lot less common, as it is found in a wide range of foods.
Foods higher in chromium include shellfish, mussels, nuts and some fruits and vegetables, such as broccoli, pears and tomatoes.
One study found that supplementing with 1,000 mcg of chromium for two months improved insulin sensitivity by up to 38% in obese women with PCOS.