This means that to achieve ketosis, you have to limit your carb intake to less than 50 grams per day (most people should reach ketosis within a week of following the diet). To put this in perspective, the low-carb diet you’re most familiar with—the Atkins Diet—recommends about 130 grams of carbs per day. Also for reference, one bagel has about 55 grams of carbs.
^ Jump up to: a b c d e f g h i j k l m n o p q r s Kossoff EH, Zupec-Kania BA, Amark PE, Ballaban-Gil KR, Bergqvist AG, Blackford R, et al. Optimal clinical management of children receiving the ketogenic diet: recommendations of the International Ketogenic Diet Study Group. Epilepsia. 2009 Feb;50(2):304–17. doi:10.1111/j.1528-1167.2008.01765.x. PMID 18823325
How did this diet, which was first developed in the 1920s as a treatment for children with epilepsy (and has been shown to reduce seizures in patients whose epilepsy symptoms aren’t responding to other medications), become the diet du jour, and why such a discrepancy between its fandom and expert opinion? Let’s take a closer look at what “going keto” entails.
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.”
Everyone has to find their nutritional sweet spot for producing enough ketones and staying in ketosis, but “the core principle of the diet is to keep carbohydrate intake low enough, so your body continues producing ketones at elevated levels,” says Volek. “Your body adapts to this alternative fuel and becomes very efficient at breaking down and burning fat.”
One area where food tracking can be especially helpful, though, is ensuring that you're hitting the right ratios of macronutrients—protein, carbs, and fat. "The most researched version of the ketogenic diet derives 70 percent of calories from healthy fats, 20 percent from protein, and only 10 percent from carbs," explains Charles Passler, D.C., nutritionist, and founder of Pure Change. "In the ideal world, each keto meal and snack should have that same (70/20/10) ratio of macronutrients, but studies have shown that you'll still achieve great results even if each meal varies slightly from that ratio, just as long as you don't exceed 50 grams per day of carbs, or eat those carbs in one sitting," says Passler. In order to achieve these ratios without a preset meal plan from a dietitian or doctor, some food tracking is probably going to be necessary. But once you get the hang of things, you may not need it anymore.
Bonnie J. Brehm, Randy J. Seeley, Stephen R. Daniels, and David A. D’Alessio, “A Randomized Trial Comparing a Very Low Carbohydrate Diet and a Calorie-Restricted Low Fat Diet on Body Weight and Cardiovascular Risk Factors in Healthy Women,” The Journal of Clinical Endocrinology & Metabolism: Vol 88, No 4; January 14, 2009. http://press.endocrine.org/doi/full/10.1210/jc.2002-021480.
Fairly recently, the diet was introduced as a weight-loss diet by an Italian professor of surgery, Dr. Gianfranco Cappello of Sapienza University in Rome. In his 2012 study, about 19,000 dieters received a high-fat liquid diet via a feeding tube inserted down the nose. The study showed an average weight loss of more than 20 pounds in participants, most of whom kept it off for at least a year. The researchers reported a few minor side effects, like fatigue.
Bulk buy and cook. If you’re someone who doesn’t like to spend a lot of time in the kitchen, this is the best of both worlds. Buying your food at bulk (specifically from wholesalers) can reduce the cost per pound tremendously. Plus, you can make ahead food (bulk cook chicken thighs for pre-made meat, or cook entire meals) that are used as leftovers, so you spend less time cooking.
Long-term use of the ketogenic diet in children increases the risk of slowed or stunted growth, bone fractures and kidney stones. The diet reduces levels of insulin-like growth factor 1, which is important for childhood growth. Like many anticonvulsant drugs, the ketogenic diet has an adverse effect on bone health. Many factors may be involved such as acidosis and suppressed growth hormone. About 1 in 20 children on the ketogenic diet will develop kidney stones (compared with one in several thousand for the general population). A class of anticonvulsants known as carbonic anhydrase inhibitors (topiramate, zonisamide) are known to increase the risk of kidney stones, but the combination of these anticonvulsants and the ketogenic diet does not appear to elevate the risk above that of the diet alone. The stones are treatable and do not justify discontinuation of the diet. Johns Hopkins Hospital now gives oral potassium citrate supplements to all ketogenic diet patients, resulting in a sevenfold decrease in the incidence of kidney stones. However, this empiric usage has not been tested in a prospective controlled trial. Kidney stone formation (nephrolithiasis) is associated with the diet for four reasons:
“A lot of folks find that batch cooking once or twice a week saves a tremendous amount of time and keeps you from spending every evening in the kitchen,” Weaver says. “When keto meal planning, you want to follow general good meal planning practices, like shopping for the week’s food all at once, which helps to save money, and prepping your vegetables when you get home. These 10 keto recipes are so good you’ll forget you’re on a diet.
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.
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 nutrient deficiencies and talk about vitamin supplementation, as you won’t be eating whole grains, dairy, or fruit, and will eliminate many veggies. “A diet that eliminates entire food groups is a red flag to me. This isn’t something to take lightly or dive into headfirst with no medical supervision,” she says.