Written by Mary Jane Brown, PhD, RD (UK) on July 12, 2017

Polycystic ovary syndrome (PCOS) affects up to 15–20% of women of reproductive age (1).

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 (2).

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 (3, 4).

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 (5, 6).

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 (7, 8).

One study found that menstrual regularity improved in 95% of women on a low-GI, weight loss diet, compared to 63% of women on a standard weight loss diet (7).

Another study including 60 overweight women with PCOS found that following a high-protein, low-GI, weight loss diet improved insulin sensitivity and reduced levels of inflammatory markers, compared to a standard weight loss diet (8).