Yancy has seen similar results in his practice. “Carbohydrate intake is the main driver of blood sugar. So if you’re able to lower blood sugar by reducing carbohydrate intake, then you may be able to reduce diabetes medication,” he says. “We’ve seen people come off of hundreds of units of insulin just by changing the way they eat, and that can happen really quickly, in just a few weeks.”
The research on how diet affects PCOS is minimal, but there is one compelling study on the ketogenic diet and women with PCOS. In this study, five overweight women ate a ketogenic diet (20 grams of carbohydrates or less per day) for 24 weeks. The results were astounding — average weight loss was 12%, free testosterone decreased by 22%, and fasting insulin levels dropped by 54%. What’s even more impressive is that two of the women became pregnant despite previous infertility problems.
Still, research on the relationship between the keto diet and mental clarity, as well as anxiety and depression, is still in its early stages, and not all people who try the keto diet report noticeable changes in the ways they think. In fact, some people report an increase in brain fog after switching to the keto diet, though this might be explained by the "keto flu", which describes the flu-like symptoms people tend to experience in the first few weeks after beginning the keto diet.
Since our body isn’t used to using ketones, we tend to feel flu-like when in ketosis. Lots of brain fog, fatigue, headaches, nausea and poor endurance. You also get bad smelling breath, sweat and pee from the acetone (a byproduct of fat metabolism). Sexy? Not so much. Thankfully, if you are in ketosis long enough, a lot of people report that most of these side effects start to go away.
In a second study,2 a Harvard-led research team evaluated the benefit of a ketogenic diet in both children and adults with type 1 diabetes despite concerns about a possible negative effect on growth and development in children following such a restricted diet. These researchers report "exceptional" glucose control with little adverse effects. However, the participants were recruited from a closed Facebook group, TypeOneGrit, for people who follow a diet and diabetes program based on the recommendations in the Diabetes Solution,3 a book by Richard K Bernstein, MD, who devised this program to manage his own type 1 diabetes.
Difficulty. Many experts question how long a person can realistically give up carbs. “This is a very restrictive diet that requires a drastic change in eating behaviors and even taste,” says Sandra Arevalo, MPH, RDN, CDE, a certified diabetes educator and spokesperson for the Academy of Nutrition and Dietetics. “It isn’t very practical or easy to maintain, for people both with and without diabetes.” That’s not saying you can’t stick with it, but before you commit, make a plan and set measurable goals to help you stay on track. Being prepared with the right foods can also help. Urbanski recommends making a shopping list that focuses on a few basic keto-friendly meals and snacks, so you’ll always have the right foods on hand to ensure success.
The benefits of a ketogenic diet have been well documented for those living with Type 2 diabetes. Not only does the diet help manage blood sugar but it promotes weight loss as well. The results for those living with Type 1 are less conclusive. Many studies tend to address low carb diets like paleo and Atkins, which focus more on types of low carb food to eat, unlike a keto diet, which pays close attention to macronutrients and staying in ketosis. There seem to be fewer studies exploring the latter, but there is observational information that seems to indicate the diet offers a way to manage A1C levels and glycemic control. Many people with diabetes who abide by the keto diet have found that they significantly reduce their use of insulin.