Because low-carbohydrate diets have been shown to reduce insulin resistance, it may make sense to try the keto diet for PCOS management. However, the Ketogenic Diet, (Keto) is a special high-fat, low carbohydrate diet designed to control seizures in individuals diagnosed with epilepsy.
In pop culture, the Keto diet is viewed as a quick weight loss solution. Because the Keto diet is an extremely strict, nutritionally unbalanced diet, we do not recommend it for PCOS management. The Keto diet is a very low-carb high-fat diet which does not restrict calories. Instead, the keto diet promotes food imbalance rather than eating a variety of high quality of foods. In order to create a lifetime of nutritionally sound habits, follow the advice of your dietitian to manage your PCOS. Avoid the Keto diet.
Below are a few reasons why the Keto Diet is not a good fit for people with PCOS.
"Trying to reach Ketosis" can have unpleasant side effects
In practice, many people who claim to practice the keto diet fail to ever reach ketosis. This outcome rarely happens because of a lack of effort. Instead, it's simply hard to restrict total carbohydrates to the ~5% level needed to bump your body into fat-burning ketosis.
The unpleasant side effects can include:
- Carbohydrate withdrawal can include headache, chills, brain fog, dizziness and irritability
- Sugar cravings, which can cause the inflammation associated with PCOS
- An uncomfortable link to disordered eating: Women with PCOS are more likely to also experience disordered eating (two studies, here and here). We do not recommend these types of restrictive diets for women with PCOS.
- You may experience mood swings – food and mood go together. When the brain gets less sugar from the blood for energy, this shortfall can impact mood and result in you feeling irritable.
The Keto Diet for PCOS is very difficult to sustain for a long term
Multiple studies have demonstrated that a very-low carbohydrate keto diet can help you lose weight quickly. The first study was published in London-based Nutrition and Metabolism, and the second study was presented in the Journal of Translational Medicine. The major shortcoming of these studies is that participants either:
Were not closely monitored; i.e. only had monthly check-ins:
Only followed the ketogenic diet for 12 weeks
Because the keto diet is not sustainable in the long run, it may increase your risk for being overweight in the future. The keto diet usually produces rapid weight loss in the short-term, but it’s very unlikely to persist for a long amount of time. Because PCOS cannot be “cured”, there is need for long-term management that can be easily and consistently followed to decrease PCOS symptoms.
The Keto Diet may actually make your PCOS symptoms worse
The glands that regulate the hormones in your body are very sensitive. When you severely restrict carbohydrates, the physiological stress on your body may cause your adrenal glands to start producing more cortisol (one of your body’s stress hormones). Cortisol causes blood sugar levels to increase and can actually make insulin resistance worse over time. Elevated levels of cortisol lead to more belly fat.
Research has shown that holding excess fat in your abdominal area increases a person’s risk for health conditions including type 2 diabetes and heart disease more than holding fat in other areas of the body. Although initial weight loss may occur on a keto diet (as would cutting out any entire food group) the long-term impact of elevated cortisol levels from overly restricting carbohydrate intake may actually do more harm than good.
Research has also shown that limiting carbohydrates may be harmful for your hormone function and balance. Restricting carbohydrates can result in irregular menstrual cycles or the complete loss of a period all together – which is the exact opposite of what we want for women with PCOS. Also, low carbohydrate intake can affect your mood, concentration and energy.
We have been critical of the Keto Diet for multiple reasons, including its negative long-term effects on proper liver function. You can read our broader Keto Diet discussion on this blog post.