"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.
If you’re looking to get a jump start on your health and fitness goals this year, you may be thinking about trying the ketogenic diet. Maybe you’ve heard the phrase before — it’s a huge diet buzzword — but aren’t sure what it means. Here’s a primer: The ketogenic diet is an eating plan that drives your body into ketosis, a state where the body uses fat as a primary fuel source (instead of carbohydrates), says Stacey Mattinson, RDN, who is based in Austin, Texas.
But people who started following the keto diet noticed weight loss for a few reasons: When you eat carbs, your body retains fluid in order to store carbs for energy (you know, in case it needs it). But when you’re not having much in the carb department, you lose this water weight, says Warren. Also, it's easy to go overboard on carbohydrates—but if you're loading up on fat, it may help curb cravings since it keeps you satisfied.
That's because my intro to this seemingly new plan was when I worked in a hospital, where ketogenic diets were specifically used as a medical nutrition therapy for pediatric patients with seizure disorders, for whom medication was no longer effective. In other words: It was used as an absolute last resort for families who felt otherwise hopeless in the face of a neurological disease, and under strict medical supervision.
Beyond just fat loss, ketosis has an additional benefit in that it spares muscle when you’re eating at a deficit. On a normal diet, when you eat fewer calories than you need for the day, your body breaks down muscle and fat in nearly equal amounts to make up for the difference. With keto, your body is primed to burn mostly fat, particularly if you’re meeting your protein goal for the day. This results in a better metabolism and more total fat lost. Low carb recipes offer:
In the first week, many people report headaches, mental fogginess, dizziness, and aggravation. Most of the time, this is the result of your electrolytes being flushed out, as ketosis has a diuretic effect. Make sure you drink plenty of water and keep your sodium intake up.6One of the fathers of keto, Dr. Phinney, shows that electrolyte levels (especially sodium) can become unbalanced with low carb intake.
Probably, and there are a few reasons why, Keatley says. For starters, people usually reduce their daily caloric intake to about 1,500 calories a day because healthy fats and lean proteins make you feel fuller sooner—and for a longer period of time. And then there’s the fact that it takes more energy to process and burn fat and protein than carbs, so you're burning slightly more calories than you did before. Over time, this can lead to weight loss.
Chasing blood Ketones instead of focusing on hormone signals: "The higher the number means you have more Ketones circulating in your bloodstream, but that does not mean that you are better at burning fat for fuel," Mavridis points out. "You must be in nutritional Ketosis, which is described as being between 1.5 - 3.0 mol/L on the blood Ketone meter. You will know once you are fat-adapted from hormonal signals, and not from higher Ketones on the blood meter," she adds.
When you eat tons of carbs, your blood sugar is consistently elevated, and then so is insulin. Insulin is a hormone that keeps your blood sugar in check by shuttling the glucose into cells, but when there’s a consistently high amount of insulin, your cells become resistant. This insulin resistance makes it easier to store fat, and chronically high levels of insulin also cause excessive inflammation in the body, which contributes to heart disease, high blood pressure, and potentially type 2 diabetes.
By cutting carb intake significantly, we can drastically reduce insulin resistance, the precursor to type 2 diabetes. In addition, low carb diets, along with exercise, can be very effective at helping alleviate the symptoms and progression of type 2 diabetes. Beyond that, ketosis itself is appetite-suppressing, meaning your hunger will naturally check itself, increasing your caloric deficit and making you lose fat even faster.
So you've decided you want to try out the high-fat, low-carb diet, better-known as the fat-burning ketogenic diet. Whether it's to lose weight, have more energy, or fuel workouts differently, going keto is a popular choice right now. But figuring out a keto meal plan on your own is no easy feat, especially since eating a diet super high in fats doesn't come naturally to many people who are accustomed to the traditionally carb-heavy American diet. (It's especially hard if you're vegan and want to try keto.) But this should help: Keto experts explain how to set yourself up for success, plus provide ideas for exactly what keto foods to eat when you're first getting started. (While you're at it, check out these Low-Carb Keto drinks That Will Keep You in Ketosis.)
The first signs of ketosis are known as the “keto flu” where headaches, brain fogginess, fatigue, and the like can really rile your body up. Make sure that you’re drinking plenty of waterand eating plenty of salt. The ketogenic diet is a natural diuretic and you’ll be peeing more than normal. Take into account that you’re peeing out electrolytes, and you can guess that you’ll be having a thumping headache in no time. Keeping your salt intake and water intake high enough is very important, allowing your body to re-hydrate and re-supply your electrolytes. Doing this will help with the headaches, if not get rid of them completely.
There are numerous benefits that come with being on keto: from weight loss and increased energy levels to therapeutic medical applications. Most anyone can safely benefit from eating a low-carb, high-fat diet. Below, you’ll find a short list of the benefits you can receive from a ketogenic diet. For a more comprehensive list, you can also read our in-depth article here >