Those with epilepsy should also consult their doctor before using a ketogenic diet as part of their treatment plan. If you do opt to go through with the keto diet, consider working with a registered dietitian nutritionist who is also a certified diabetes care and education specialist. They can help you develop a healthy low-carb meal plan that is high in fat but low in saturated fats, and which contains plenty of healthy foods such as low-carb veggies.
Besides diabetes, the keto diet may also help improve short- and long-term cognition among people who are living with Alzheimer’s disease and experiencing mild cognitive impairment, according to a systematic review of randomized controlled trials. Researchers caution that further research is needed to confirm these findings and prove a cause-and-effect relationship between the ketogenic diet and preventing dementia.
Keto and Weight Loss
Looking to lower your body fat percentage? You’ve probably heard that keto diets can help — and that they can make a big impact on your weight right away. There may be some truth to that notion, although how much weight you lose will vary by individual.
“Ketogenic diets will cause you to lose weight within the first week,” says Mattinson. Thanks to its low-carb nature, keto will force the body to first use up all its glycogen stores, which is the storage form of carbohydrates, she explains. With depleted glycogen, you’ll drop water weight. While it can be motivating to see the number on the scale go down, keep in mind that most of this is water loss initially.
But the ketogenic diet can also be an effective weight loss option over time. One review suggested that this low-carb diet can spur fat loss in people with obesity when used for a couple of weeks and for up to one year. And a meta-analysis noted that one likely reason for weight loss is that all of the fat consumed when on this diet may suppress hunger.
One downside of the ketogenic diet for weight loss is that it’s difficult to maintain, especially compared to a traditional diet or other diets that have less stringent rules. “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), the very low-carbohydrate nature of keto means that you are way more limited in terms of what’s allowed on the diet, which can make everyday situations, such as eating dinner with family or going out with friends, far more difficult. Because people often find this diet tough to sustain, it’s easier to rely on as a short-term diet than as a long-term lifestyle.
Ketogenic Diet Risks
Another potential downside of the keto diet: the keto flu. One study found that across 43 different online forums for people following a keto diet, about one-third of commenters reported experiencing this short-term keto side effect. In the first few days after you begin your keto diet plan, you may experience headaches, muscle cramps, fatigue, nausea, constipation, and other flu-like symptoms, according to Harvard Health Publishing. Keto flu symptoms usually resolve within a few days to a few weeks, and you can help to counter them by drinking plenty of fluids with electrolytes, according to an article published on StatPearls in 2022.
Before starting, ask yourself what is really realistic for you, Mattinson suggests. Then get your doctor’s okay. You may also work with a local registered dietitian nutritionist to limit potential vitamin and mineral deficiencies and talk about vitamin and mineral supplements, since you won’t be eating whole grains, dairy, or fruit, and you will also eliminate many veggies. (However, you may be eating some high-fat dairy.) “A diet that eliminates entire food groups is a red flag to me. That isn’t something to take lightly or dive in to headfirst with no medical supervision,” she says.
Tips for Creating Your Ketogenic Meal Plan
If you’ve decided to move forward with trying the ketogenic diet, you will want to stick to the parameters of the eating plan. With this high-fat diet, roughly 70 to 80 percent of your calorie intake will come from fats, 10 to 20 percent from protein, and 5 to 10 percent from carbohydrates, according to the Harvard T.H. Chan School of Public Health. You’ll eat meats, fats, and oils (such as olive oil), and some nonstarchy or low-carb veggies, she says. (This very low-carb diet is different than a traditional low-carb diet, as even fewer carbs are allowed.)
The remaining calories in the ketogenic diet come from a moderate daily protein intake — about 1 gram (g) per kilogram of body weight, so a 140-pound woman would need about 64 g of protein per day. As for total carb intake: “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.
One thing to remember: “It’s easy to get ‘kicked out’ of ketosis,” says Mattinson. Meaning, if you eat something as small as a serving of blueberries, your body could exit that metabolic state, stop producing ketone bodies, and revert to burning carbohydrates for fuel rather than fat.
A Complete Food Guide to Follow
Wondering what fits into a ketogenic diet — and what doesn’t? If you have ever tried one of the many low-carb diets out there (the Atkins diet being another popular option), you’ve had a preview, in terms of needing to cut back on those starchy or other obviously high-carb foods (think packaged cookies, cakes, crackers, potato chips, and the like). But the difference here is you’ll also be loading up on fats — probably more than you’re used to. Let’s face it: High-fat diets are just less common than low-carb ones.
“It’s so important to know what foods you’ll be eating before you start, and how to incorporate more fats into your diet,” says Kristen Mancinelli, RD, author of The Ketogenic Diet: A Scientifically Proven Approach to Fast, Healthy Weight Loss, who is based in New York City. If you are considering taking supplements, as noted below, check with your doctor first.
