"The keto diet is primarily used to help reduce the frequency of epileptic seizures in children. While it also has been tried for weight loss, only short-term results have been studied, and the results have been mixed. We don't know if it works in the long term, nor whether it's safe," warns registered dietitian Kathy McManus, director of the Department of Nutrition at Harvard-affiliated Brigham and Women's Hospital.
Although excellent sources of fat, nuts add up quickly in protein and carbs, and are often inflammatory. Snack on fattier nuts such as macadamia nuts and pecans, but limit those high in inflammatory omega-6s, like peanuts and sunflower seeds. Only use nut flours (almond, coconut) in moderation, as they are packed with protein. To stay in ketosis, limit high-carb nuts like cashews, pistachios and chestnuts, and avoid most beans.
Wilder's colleague, paediatrician Mynie Gustav Peterman, later formulated the classic diet, with a ratio of one gram of protein per kilogram of body weight in children, 10–15 g of carbohydrate per day, and the remainder of calories from fat. Peterman's work in the 1920s established the techniques for induction and maintenance of the diet. Peterman documented positive effects (improved alertness, behaviour, and sleep) and adverse effects (nausea and vomiting due to excess ketosis). The diet proved to be very successful in children: Peterman reported in 1925 that 95% of 37 young patients had improved seizure control on the diet and 60% became seizure-free. By 1930, the diet had also been studied in 100 teenagers and adults. Clifford Joseph Barborka, Sr., also from the Mayo Clinic, reported that 56% of those older patients improved on the diet and 12% became seizure-free. Although the adult results are similar to modern studies of children, they did not compare as well to contemporary studies. Barborka concluded that adults were least likely to benefit from the diet, and the use of the ketogenic diet in adults was not studied again until 1999.
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.”
On a ketogenic diet, your entire body switches its fuel supply to run mostly on fat, burning fat 24-7. When insulin levels become very low, fat burning can increase dramatically. It becomes easier to access your fat stores to burn them off. This is great if you’re trying to lose weight, but there are also other less obvious benefits, such as less hunger and a steady supply of energy. This may help keep you alert and focused.