The keto diet is a popular weight-loss strategy, but the benefits extend far beyond this. Other benefits include thinking more clearly, having more energy throughout the day, and feeling less hungry between meals. The truth is, there’s a lot to unpack when it comes to keto—but rest assured, you’re in the right place. Consider this your ultimate beginner’s guide to this low-carb way of eating. In this way, a keto diet is essentially mimicking what happens to our bodies when we fast. In fact, the origins of the ketogenic diet date back to 1921, when Russel Wilder, M.D., of the Mayo Clinic, developed it as a more sustainable alternative to fasting for treating epilepsy. The diet is high in fat, moderate in protein, and very low in carbohydrates. The suggested ratios of macronutrients on a keto diet can vary among individuals but typically fall within the ranges of: What the diet does is suppress insulin, just as fasting would. The only difference is that it’s the fat from the diet fueling ketone production, whereas during starvation, ketone production is fueled by stored body fat. That said, if you are eating a ketogenic diet in a calorie deficit or practice some variation of fasting, you will be able to tap into those fat stores. Whether it be your neighbor, co-worker, or aunt, someone you know has probably lost weight on keto and told you all about it. Countless studies support these results, showing the diet to be an effective weight loss strategy. In fact, a group of researchers from Cambridge University reviewed 13 randomized controlled trials2 comparing very-low-carb high-fat ketogenic diets (VLCKD) to low-fat (LF) diets and found that individuals following VLCKD can achieve greater weight loss than those following LF diets, and better yet, keep the weight off long term. Every gram of glycogen (stored glucose) holds around three to four grams of water, so when we are burning through this, we are losing all that water, too. But don’t worry; fat loss comes next! When it comes to weight loss, the keto diet shines in its ability to provide sustainable energy and suppress appetite. In a state of ketosis, you are no longer unhealthfully tied to glucose, needing to frequently refuel throughout the day. In contrast, in a state of ketosis you essentially have an infinite source of fuel coming from either the fat that you eat or the fat you need to burn. In fact, a 2015 meta-analysis3 reviewing the effects of calorie-restricted ketogenic diets on weight loss and appetite concluded that ketogenic diets are associated with greater appetite suppression, despite eating in a calorie deficit and losing weight, compared to other types of calorie-restricted diets. In other words, the hunger pangs associated with eating less and losing weight may be blunted when done so with a keto diet. This is why people find keto (and low-carbohydrate diets in general) sustainable: because your appetite is finally no longer controlling you; you are controlling it. The keto diet does a pretty good job of preserving muscle mass4 during weight loss, improving overall body composition, and preventing metabolic rate from plummeting. Ketones themselves have a muscle-sparing effect5, and most people trying to lose weight wants to lose fat, not muscle. This means that losing weight while in ketosis can help prevent the breakdown of our hard-earned muscle, all while losing fat. It’s also worth noting that protein, too, plays an important role in preserving muscle mass during weight loss, so it’s recommended not to restrict protein too much. If you are one of those people who would do anything for that post-lunch nap, the ketogenic diet may help! Energy is less likely to fluctuate throughout the day when in ketosis, again due to constant access to a superior energy source. There are many neuroprotective properties of ketones8 such as enhanced brain energy metabolism, reduced neuroinflammation, and the calming effect ketones can have on the brain.These benefits are even more pronounced as we age and may offer protection against various age-related neurodegenerative diseases. New science is constantly emerging on how ketones may be therapeutic against various other neurological disorders, such as anxiety, depression,9 and migraines10. In fact, breath acetone is actually a good predictor of ketosis11. When we are in ketosis, a portion of the ketones gets converted into the ketone acetone, which is excreted via our breath. This is nothing to be concerned about. You can prevent this by avoiding extreme calorie restriction of prolonged fasts, as these can be very stressful on the body when taken too far. Another possible cause of hair loss is mineral and vitamin deficiencies12, such as a zinc deficiency, thus consuming foods such as shellfish, seafood, and meat can be helpful. In a study of 83 obese individuals, a long-term keto diet significantly reduced triglycerides and LDL cholesterol and increased HDL cholesterol13. In other words, the keto diet improved all measured cardiovascular disease risk factors. Women can be more sensitive to dietary changes because of the way these adjustments affect hormones related to reproduction. The effects on women’s hormones though are more likely related to calorie restriction than to keto itself. Living in a chronic calorie deficit, paired with increased exercise and weight loss, can shift hormones so dramatically that it can affect menstruation. It is especially important for women to maintain proper calorie consumption and to discontinue the diet if menstruation stops. It is also up for debate whether keto is suitable during pregnancy and breastfeeding. Despite low-carb diets being shown to benefit fertility14 and ketosis being a natural state many women enter during pregnancy15, we recommend consulting with a medical professional or a keto-savvy functional medicine doctor. Most of the side effects of keto are only short term and will likely resolve with time and proper keto-adaptation. But if there are too many signs suggesting that keto isn’t for you, it’s worth recognizing that many benefits can be derived from a less strict low-carb diet in which ketosis isn’t necessarily the goal. You won’t be getting the boosted brainpower from ketones, but you’ll probably still experience improved blood sugar levels, metabolic flexibility, and better control of your appetite, too. Here are some of the most common meal plans on a keto diet: How long it takes to enter a state of ketosis can vary from person to person, but here is a typical timeline: People tend to overthink the ketogenic diet, especially if you are switching from a very carbohydrate-heavy diet. But you should get the hang of it pretty quickly by following these tips: It also makes sense from an evolutionary perspective. But the truth is, everyone is different, and because of this, you may find you need to tweak your keto approach slightly after evaluating how you feel on a more conventional ketogenic diet. For example, women may want to practice carb cycling once a month to support healthy hormone production and minimize side effects. And, as always, if you have any concerns or are dealing with a specific health condition, talk to your doctor or a registered dietitian (ideally one who is well versed in using low-carb diets with their patients) before implementing a ketogenic diet.
