Why Protein Is Important in a PCOS Diet

For females with polycystic ovary disease (PCOS), increasing dietary protein may be a helpful strategy for weight control and for preventing prediabetes and type 2 diabetes— all common complications of the condition. While there is no specific diet that has been recommended for PCOS, general principles include adopting eating habits that help you maintain your optimal weight while avoiding excess sugar, fats, and artificial ingredients.

In addition to fueling the body with calories (along with carbohydrates and fats) and providing the building blocks for bones, muscles, skin, and blood, protein helps facilitate digestion and metabolism and plays an integral role in the synthesis of hormones, including estrogen, testosterone, and insulin. These hormones are disrupted in PCOS.

In order for an increase in dietary protein to be beneficial for managing PCOS, it must be accompanied by a relatively lower intake of carbohydrates and come from foods that are low in saturated fat. Getting the proportions and food sources right, ideally with the help of a dietitian, can be a helpful way to avoid some adverse effects of PCOS.

Benefits of Protein in PCOS

While not a cure or direct treatment for PCOS, studies show a high-protein/low-carb diet can be beneficial in a number of ways:

• Help boost metabolism: All foods have a thermic effect, which means that they impact your rate of metabolism and the number of calories burned. The thermic effect of protein is between 15 and 30%, which is far greater than that of carbohydrates (5 to 10%) or fats (0 to 3%). Eating more protein can increase the number of calories burned per day by as many as 100.
• Control appetite: Protein stimulates the production of cholecystokinin, glucagon-like peptide 1, and peptide YY, hormones that are involved in satiety, helping to reign in appetite and reduce cravings.
• Improve blood sugar control: All foods increase glucose (blood sugar) levels. Because protein is digested slowly, its impact on blood sugar is relatively low. Additionally, carbohydrates break down directly into glucose, while proteins are broken down into amino acids, which take time to convert to glucose. A 2019 study in Diabetologia reported that adults with type 2 diabetes who followed a high-protein diet for six weeks had reductions in both postprandial (post-eating) and fasting glucose levels.
• Temper the insulin response: Protein stimulates the release of glucagon, a hormone that raises blood glucose levels and counteracts the action of insulin. The right amount of protein can help balance the levels of glucagon and insulin in the blood.

Research looking at the effects of a high-protein diet on PCOS has been promising. For example, a 2012 study from Denmark reported that people with PCOS who followed such a diet for six months lost an average of nine pounds of body fat.

Similar results were seen in a 2012 study from Iran in which 60 overweight women with PCOS who followed a diet made up of 30% protein lost weight and also had lower testosterone levels and improved insulin sensitivity.

Dietary Recommendations

There are no specific dietary recommendations for women with PCOS. There is evidence, however, to suggest increasing the amount of protein in the diet from 15% of calories to 30% or even more than 40% may be highly beneficial.

This is along the top end of recommendations by the Department of Health and Human Services (DHHS) that females age 19 and over get 10 to 35% or more of their daily calories from protein.

There are reasons for this guidance. Even though protein is broken down slowly, 50 to 60% of it is converted to glucose. If eaten alone, its effect on blood sugar is minimal since the glucose will be distributed to the bloodstream at a slow, steady pace.

The same may not be true when protein, carbohydrate, and fat are combined. In some cases, protein actually can increase blood sugar levels if the balance of protein, carbohydrates, and fat is not carefully controlled.

A 2015 review of studies in Diabetes Care demonstrated this, reporting that combining 30 grams of protein with 35 grams of carbohydrates can increase postprandial blood glucose by 2.6 mmol/L. This is enough for some people to push them from a normal to a high blood sugar level.

Tips and Considerations

If you decide to try a high-protein diet to prevent weight gain and/or lower your risk of diabetes due to PCOS, the best way to start is to speak with a dietitian experienced in metabolic disorders.

To lose one pound of weight per week, you would need to reduce your daily calorie intake by 500 calories. This makes preparation all the more important since you will need to reduce calories with an entirely new ratio of protein, carbohydrates, and fats—while maintaining your nutritional needs.

Protein Sources

The best sources of protein for weight loss are low in saturated fat.

Good choices include:

• Almonds: 6 g protein and 164 calories per ounce
• Eggs: 6 g protein and 78 calories per egg
• Greek Yogurt: 7 g protein and 100 calories per 6-ounce serving
• Milk: 8 g protein and 149 calories per cup
• Quinoa: 8 g protein and 222 calories per one cup (cooked)
• Pumpkin Seeds: 9 g protein and 158 calories per 1-ounce serving
• Oatmeal: 11 g protein and 307 calories per one cup (uncooked)
• Lentils: 18 g protein and 230 calories per one cup (cooked)
• Shrimp: 20 g protein and 84 calories per 3-ounce serving
• Lean Sirloin: 25 g protein and 186 calories per 3-ounce serving
• Turkey Breast: 26 g protein and 125 calories per 3-ounce serving
• Canned Tuna: 27 g protein and 128 calories per can
• Cottage Cheese: 28 g protein and 163 calories per cup
• Soybeans: 29 g protein and 173 calories per cup
• Chicken Breast (Without Skin): 53 g protein and 284 calories per half breast

Animal vs. Plant-Based Proteins

There are two sources of dietary protein: plant (such as soy, nuts, and beans) and animal (meat, poultry, fish, dairy, and eggs). With the exception of soy, only animal-based proteins are complete proteins, meaning they contain all nine essential amino acids the body needs to function normally,

Because plant-based proteins do not, it's important for people who do not eat meat (namely, vegans and vegetarians) to learn how to combine different plant sources of protein to get an ample amount of each amino acid each day.

For example, grains are low in the amino acid lysine, while beans and nuts are low in methionine. When grains and legumes are combined (such as rice and beans or peanut butter on whole-wheat bread), you can get all of the essential amino acids.

A Word From Verywell

If you have PCOS and struggle with weight or blood sugar control, you may well want to consider trying a high-protein/low-carb diet. Work with a healthcare provider or dietitian to find the eating regimen that is appropriate for your age, weight, and medical condition that also is based on foods you truly enjoy. This way you'll be able to sustain your diet and any benefits it provides.