You've likely heard horror stories of what competitors feel like when they cut carbs low, or when the average bro talks about going keto. However, the odds are that those people were not actually in nutritional ketosis, or more importantly, following a well-formulated ketogenic diet. Yes, you may experience some fogginess and discomfort, but it doesn't have to be intense if you handle it right.
A keto diet has shown to improve triglyceride levels and cholesterol levels most associated with arterial buildup. More specifically low-carb, high-fat diets show a dramatic increase in HDL and decrease in LDL particle concentration compared to low-fat diets.3A study in the long-term effects of a ketogenic diet shows a significant reduction in cholesterol levels, body weight, and blood glucose. Read more on keto and cholesterol >
The Johns Hopkins Hospital protocol for initiating the ketogenic diet has been widely adopted.[42] It involves a consultation with the patient and their caregivers and, later, a short hospital admission.[18] Because of the risk of complications during ketogenic diet initiation, most centres begin the diet under close medical supervision in the hospital.[9]
When ketosis kicks in, the body switches from stealing protein for fuel to burning fat. “The body starts to rely more heavily on fat stores,” Notte explains. Molecules called ketones are released when body fat is metabolized, and some cells in the brain can use ketones for fuel. However, your brain needs more than 100 grams of carbohydrates a day, according to research, and while your body makes the switch to relying on fat—ketones—for energy, your brain can suffer.
The remaining calories in the keto diet come from protein — about 1 gram (g) per kilogram of body weight, so a 140-pound woman would need about 64 g of protein total. As for carbs: “Every body is different, but most people maintain ketosis with between 20 and 50 g of net carbs per day,” says Mattinson. Total carbohydrates minus fiber equals net carbs, she explains.

Con: Results can vary depending on how much fluid you drink. By drinking more water, you dilute the concentration of ketones in the urine and thus a lower level of ketones will be detected on the strips. The strips don’t show a precise ketone level. Finally, and most importantly, as you become increasingly keto-adapted and your body reabsorbs ketones from the urine, urine strips may become unreliable, even if you’re in ketosis.
A modified version of the ketogenic diet, which allows you to eat protein more liberally — at 20 to 30 percent of your total calories — with the same carbohydrate restriction, is the more commonly used version of the diet today. Some of the aims of the latest version of the ketogenic diet are weight loss, weight management, and improved athletic performance.
One downside to a ketogenic diet for weight loss is the difficulty maintaining it. “Studies show that weight loss results from being on a low-carb diet for more than 12 months tend to be the same as being on a normal, healthy diet,” says Mattinson. While you may be eating more satiating fats (like peanut butter, regular butter, or avocado), you’re also way more limited in what’s allowed on the diet, which can make everyday situations, like eating dinner with family or going out with friends, far more difficult. Because people often find it tough to sustain, it’s easy to rely on it as a short-term diet rather than a long-term lifestyle.
×