Wondering what fits into a keto diet — and what doesn’t? “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. We asked her for some guidelines.
The MIND diet, or Mediterranean-DASH Intervention for Neurodegenerative Delay, is a sort of hybrid between the DASH diet and the Mediterranean diet. It features foods meant to slow the progression or development of Alzheimer’s disease, the most common form of dementia and an incurable neurodegenerative condition that more than 5 million Americans are living with, according to the Alzheimer’s Association. (12) Some research backs up this notion, including a study published in September 2016 in Alzheimer’s Dementia that found a link between following the MIND Diet and a reduced risk of the disease. (13)
Eating a healthy diet and staying active is important for everyone. For people with diabetes (both type 1 and type 2), prediabetes, and obesity, food and exercise plays an even greater role in managing day-to-day health. Despite all the popular articles and books, the research on nutrition, exercise, and obesity is very complex, and there is still a lot we don’t know.
In its 2016 report “Healthy Eating Guidelines & Weight Loss Advice,” the Public Health Collaboration, a U.K. nonprofit, evaluated evidence on low-carbohydrate, high-fat diets. (The Keto diet falls under the LCHF umbrella.) Among 53 randomized clinical trials comparing LCHF diets to calorie-counting, low-fat diets, a majority of studies showed greater weight loss for the Keto-type diets, along with more beneficial health outcomes. The collaboration recommends weight-loss guidelines that include a low-carbohydrate, high-fat diet of real (rather than processed) foods as an acceptable, effective and safe approach.

Dr. Gardner and his colleagues designed the study to compare how overweight and obese people would fare on low-carbohydrate and low-fat diets. But they also wanted to test the hypothesis — suggested by previous studies — that some people are predisposed to do better on one diet over the other depending on their genetics and their ability to metabolize carbs and fat. A growing number of services have capitalized on this idea by offering people personalized nutrition advice tailored to their genotypes.
Here’s what we do know: The keto diet may be useful in treating symptoms of epilepsy, a seizure disorder. “The use of keto in treating epilepsy has the most evidence,” Angelone says. One study conducted by Johns Hopkins Medicine, for example, followed epileptic patients on the keto diet and found that 36 percent of them had a 50 percent reduction in seizures after three months on the diet, and 16 percent were seizure-free. However, experts aren't entirely sure why the keto diet has this affect, she adds.
Make things yourself. While it’s extremely convenient to buy most things pre-made or pre-cooked, it always adds to the price per pound on items. Try prepping veggies ahead of time instead of buying pre-cut ones. Try making your stew meat from a chuck roast. Or, simply try to make your mayo and salad dressings at home. The simplest of things can work to cut down on your overall grocery shopping.
Vitamin D is needed for healthy bones by maintaining normal blood levels of calcium and phosphorus and for maintenance of a healthy immune system. A deficiency in children can result in rickets, and a deficiency in adults can cause osteomalacia. An inadequate diet, limited exposure to sunlight, and malabsorption can cause the deficiency. Dietary sources of vitamin D are
Swanson, a professor of neurology who has researched the impacts of ketogenic diets on inflammation in the brain, got curious about the ketogenic diet when trying to treat the inflammation that persists for days after a person suffers a stroke. When he tried inducing a ketogenic state in mice with stroke injuries, he said, “I was overwhelmed by the effect.” Blocking glucose metabolism worked to suppress inflammatory genes, which in turn helped stroke healing.
Type 2 diabetes. One study found that being on the keto diet for one year reversed diabetes for up to 60 percent of participants. With an average weight loss of 30 pounds, they dramatically reduced or eliminated their need for insulin and no longer needed oral hypoglycemic drugs. The keto diet is also easier to sustain than the calorie-restricted diet or the protein-sparing modified fast.

“There are a million reasons why dieters fail, and the reasons vary from one person to the next,” explains Somer. “People lie about what they are eating, underestimating their calorie intake by about 700 to 800 calories a day.” Exercise is also grossly misinterpreted by a lot of dieters. “They think/say they exercise far more than they really do,” Somer elaborates.
Variations on the Johns Hopkins protocol are common. The initiation can be performed using outpatient clinics rather than requiring a stay in hospital. Often, no initial fast is used (fasting increases the risk of acidosis, hypoglycaemia, and weight loss). Rather than increasing meal sizes over the three-day initiation, some institutions maintain meal size, but alter the ketogenic ratio from 2:1 to 4:1.[9]
During the 1920s and 1930s, when the only anticonvulsant drugs were the sedative bromides (discovered 1857) and phenobarbital (1912), the ketogenic diet was widely used and studied. This changed in 1938 when H. Houston Merritt, Jr. and Tracy Putnam discovered phenytoin (Dilantin), and the focus of research shifted to discovering new drugs. With the introduction of sodium valproate in the 1970s, drugs were available to neurologists that were effective across a broad range of epileptic syndromes and seizure types. The use of the ketogenic diet, by this time restricted to difficult cases such as Lennox–Gastaut syndrome, declined further.[10]
After a grueling workout, there's a good chance you're going to be feeling it (we're talking sore thighs, tight calves). Relieve post-fitness aches by submerging your lower body in a cold bath (50 to 55 degrees Fahrenheit; you may have to throw some ice cubes in to get it cold enough) for 10 to 15 minutes. "Many top athletes use this trick to help reduce soreness after training sessions," says Andrew Kastor. And advice we love: "An athlete training for an important race should consider getting one to two massages per month to help aid in training recovery," adds Kastor. Now that's speaking our language!
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.
Another difference between older and newer studies is that the type of patients treated with the ketogenic diet has changed over time. When first developed and used, the ketogenic diet was not a treatment of last resort; in contrast, the children in modern studies have already tried and failed a number of anticonvulsant drugs, so may be assumed to have more difficult-to-treat epilepsy. Early and modern studies also differ because the treatment protocol has changed. In older protocols, the diet was initiated with a prolonged fast, designed to lose 5–10% body weight, and heavily restricted the calorie intake. Concerns over child health and growth led to a relaxation of the diet's restrictions.[19] Fluid restriction was once a feature of the diet, but this led to increased risk of constipation and kidney stones, and is no longer considered beneficial.[18]
Whether you're heading off to spin class, boot camp, or any other exercise, it's always important to hydrate so you can stay energized and have your best workout. Electrolyte-loaded athletic drinks, though, can be a source of unnecessary calories, so "drinking water is usually fine until you're exercising for more than one hour," says Newgent. At that point, feel free to go for regular Gatorade-type drinks (and their calories), which can give you a beneficial replenishment boost. But worry not if you like a little flavor during your fitness: There are now lower- cal sports drinks available, adds Newgent, so look out for 'em in your grocery aisles.
Another way to stave off fatigue is to load your diet with foods rich in flavonoids, like blueberries, blackberries, and acai juice. “Our research shows that flavonoids interact with receptors in the brain that lessen the perception of tiredness. So while they’re not necessarily energy-boosting, they are fatigue-reducing,” says Talbott. About half a cup of blueberries will do the trick. Another easy strategy? Drink water throughout the day. The sluggish feeling that you get late in the afternoon, which then drives you to the vending machine, is often your body telling you that it’s low in fluid, says Talbott. The best gauge of hydration is the color of your urine, which should be almost clear if you’re well hydrated. Keep a bottle of water nearby and sip it all day, and drink a large glass of water with every meal or snack.
Carbohydrates are the primary source of fuel for your body. Your red blood cells and most parts of your brain derive all of their energy from carbohydrates. An adequate consumption of carbohydrates also allows your body to use protein and fat for their necessary requirements, it prevents ketosis, it provides fiber, and it's the source of sweetness in your foods.
A computer program such as KetoCalculator may be used to help generate recipes.[47] The meals often have four components: heavy whipping cream, a protein-rich food (typically meat), a fruit or vegetable and a fat such as butter, vegetable oil, or mayonnaise. Only low-carbohydrate fruits and vegetables are allowed, which excludes bananas, potatoes, peas, and corn. Suitable fruits are divided into two groups based on the amount of carbohydrate they contain, and vegetables are similarly divided into two groups. Foods within each of these four groups may be freely substituted to allow for variation without needing to recalculate portion sizes. For example, cooked broccoli, Brussels sprouts, cauliflower, and green beans are all equivalent. Fresh, canned, or frozen foods are equivalent, but raw and cooked vegetables differ, and processed foods are an additional complication. Parents are required to be precise when measuring food quantities on an electronic scale accurate to 1 g. The child must eat the whole meal and cannot have extra portions; any snacks must be incorporated into the meal plan. A small amount of MCT oil may be used to help with constipation or to increase ketosis.[37]
Becky Duffett is a contributing nutrition editor for Fitbit and a lifestyle writer with a passion for eating well. A former Williams-Sonoma cookbook editor and graduate of San Francisco Cooking School, she’s edited dozens of cookbooks and countless recipes. City living has turned her into a spin addict—but she’d still rather be riding a horse. She lives in the cutest neighborhood in San Francisco, spending weekends at the farmers’ market, trying to read at the bakery, and roasting big dinners for friends.
In many developing countries, the ketogenic diet is expensive because dairy fats and meat are more expensive than grain, fruit and vegetables. The modified Atkins diet has been proposed as a lower-cost alternative for those countries; the slightly more expensive food bill can be offset by a reduction in pharmaceutical costs if the diet is successful. The modified Atkins diet is less complex to explain and prepare and requires less support from a dietitian.[55]

I admit it: I was once one of “those women” for whom post-pregnancy weight loss was relatively quick and painless. I’ve never been model-skinny, but after the birth of my first two children my previous waistline was recovered with little to no effort. Yeah, I know what you want to call me, and I don’t blame you. So kick back and laugh when I tell you that the pounds decided they wanted to take up permanent residence after my third son was born. No amount of calorie counting or exercise did the trick, which threw me for a tailspin worse than those teacups at Disney World.

Around this time, Bernarr Macfadden, an American exponent of physical culture, popularised the use of fasting to restore health. His disciple, the osteopathic physician Dr. Hugh William Conklin of Battle Creek, Michigan, began to treat his epilepsy patients by recommending fasting. Conklin conjectured that epileptic seizures were caused when a toxin, secreted from the Peyer's patches in the intestines, was discharged into the bloodstream. He recommended a fast lasting 18 to 25 days to allow this toxin to dissipate. Conklin probably treated hundreds of epilepsy patients with his "water diet" and boasted of a 90% cure rate in children, falling to 50% in adults. Later analysis of Conklin's case records showed 20% of his patients achieved freedom from seizures and 50% had some improvement.[10]

The word diet first appeared in English in the 13th century. Its original meaning was the same as in modern English, “habitually taken food and drink.” But diet was used in another sense too in the Middle and early modern English periods to mean “way of living.” This is, in fact, the original meaning of diet’s Greek ancestor diaita, which is derived from the verb diaitasthan, meaning “to lead one’s life.” In Greek, diaita, had already come to be used more specifically for a way of living prescribed by a physician, a diet, or other regimen.
This principle involves eating low-energy-dense foods and can help you lose weight by feeling full on fewer calories. Healthy choices in each of the other food groups in moderate amounts make up the rest of the pyramid — including whole-grain carbohydrates, lean sources of protein such as legumes, fish and low-fat dairy, and heart-healthy unsaturated fats.
The ketogenic diet has been studied in at least 14 rodent animal models of seizures. It is protective in many of these models and has a different protection profile than any known anticonvulsant. Conversely, fenofibrate, not used clinically as an antiepileptic, exhibits experimental anticonvulsant properties in adult rats comparable to the ketogenic diet.[58] This, together with studies showing its efficacy in patients who have failed to achieve seizure control on half a dozen drugs, suggests a unique mechanism of action.[56]

This year, we learned that Americans don’t necessarily associate milk with dairy. That’s probably not surprising given the onslaught of non-dairy milks we’ve seen in recent years. But with more base ingredients than ever—almond, peanut, coconut, cashew, hemp, oat, pecan, flax, and pea protein, to name a few—it was a top healthy eating trend of 2018. Pinterest’s List of 100 Emerging Trends for 2019 noted searches for oat milk were up 186 percent. Even if you’re a dairy milk drinker, it’s worth considering expanding your milk repertoire. Each one has a unique flavor and texture, and therefore, you can customize your food and beverage experience by selecting different varieties. Coconut milk gives your smoothie a tropical flair, peanut milk is distinctly nutty, making it a nice match for overnight oats or chia pudding, and oat milk is full-bodied, so it works well in lattes. Just like I stock a variety of different nuts to keep meals and snacks interesting, I keep a few milks on hand to make my dishes that much more delicious. One final word on alternative milks: Some flavors have added sugars so be on the lookout to make sure you’re staying within the daily limits of 6 teaspoons for women, 9 for men.
Children who discontinue the diet after achieving seizure freedom have about a 20% risk of seizures returning. The length of time until recurrence is highly variable, but averages two years. This risk of recurrence compares with 10% for resective surgery (where part of the brain is removed) and 30–50% for anticonvulsant therapy. Of those who have a recurrence, just over half can regain freedom from seizures either with anticonvulsants or by returning to the ketogenic diet. Recurrence is more likely if, despite seizure freedom, an electroencephalogram shows epileptiform spikes, which indicate epileptic activity in the brain but are below the level that will cause a seizure. Recurrence is also likely if an MRI scan shows focal abnormalities (for example, as in children with tuberous sclerosis). Such children may remain on the diet longer than average, and children with tuberous sclerosis who achieve seizure freedom could remain on the ketogenic diet indefinitely.[46]
Insulin is a hormone that lets your body use or store sugar as fuel. Ketogenic diets make you burn through this fuel quickly, so you don’t need to store it. This means your body needs -- and makes -- less insulin. Those lower levels may help protect you against some kinds of cancer or even slow the growth of cancer cells. More research is needed on this, though.
That’s why many health experts are concerned about people on the keto diet, especially those who try it without the guidance of a doctor or nutritionist. Doctors say that high-fat diets like this one may raise cholesterol levels, and some studies suggest that they increase the risk of diabetes. Some have even called it a “cardiologist’s nightmare.”
There’s a large spectrum of where people can fall on a vegetarian diet: For example, vegans consume no animal products, whereas ovo-lacto vegetarians eat both dairy and eggs. The eating style may help with weight loss, suggests a review published in August 2017 in Nutrients, but some vegans and vegetarians may become deficient in specific nutrients, such as calcium, iron, zinc, and vitamin B12, according to an article published in December 2017 in Nutrition, Metabolism and Cardiovascular Diseases. (23,24)
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