"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.
A lot of changes are happening in your body and you’re going to feel it! The first five to seven days can be pretty rough, but your body is getting over its dependency on sugar. During this time of transition it is essential that you supplement electrolytes. Your body is flushing out lots of water, and with that goes electrolytes. The Keto Flu can be greatly reduced if you add sodium, potassium and magnesium to your diet. Check out our supplements page for a list of electrolyte supplements we recommend. Stay on course and you’ll start feeling better in no time!
In a recent study in the Journal of Sports Medicine and Physical Fitness, Weiss and his colleagues found that participants performed worse on high-intensity cycling and running tasks after four days on a ketogenic diet, compared to those who’d spent four days on a high-carb diet. Weiss says that the body is in a more acidic state when it’s in ketosis, which may limit its ability to perform at peak levels.
On the ketogenic diet, carbohydrates are restricted and so cannot provide for all the metabolic needs of the body. Instead, fatty acids are used as the major source of fuel. These are used through fatty-acid oxidation in the cell's mitochondria (the energy-producing parts of the cell). Humans can convert some amino acids into glucose by a process called gluconeogenesis, but cannot do this by using fatty acids. Since amino acids are needed to make proteins, which are essential for growth and repair of body tissues, these cannot be used only to produce glucose. This could pose a problem for the brain, since it is normally fuelled solely by glucose, and most fatty acids do not cross the blood–brain barrier. However, the liver can use long-chain fatty acids to synthesise the three ketone bodies β-hydroxybutyrate, acetoacetate and acetone. These ketone bodies enter the brain and partially substitute for blood glucose as a source of energy.
If you're a protein-lover, you may think this diet is for you considering all the other foods that are eliminated. But the diet requires that protein make up 20 to 25 percent of total calories—so eating too many eggs or chicken breasts can make you top this protein amount pretty easily. (Related: 8 Common Keto Diet Mistakes You Could Be Getting Wrong)
In the 1960s, it was discovered that medium-chain triglycerides (MCTs) produce more ketone bodies per unit of energy than normal dietary fats (which are mostly long-chain triglycerides). MCTs are more efficiently absorbed and are rapidly transported to the liver via the hepatic portal system rather than the lymphatic system. The severe carbohydrate restrictions of the classic ketogenic diet made it difficult for parents to produce palatable meals that their children would tolerate. In 1971, Peter Huttenlocher devised a ketogenic diet where about 60% of the calories came from the MCT oil, and this allowed more protein and up to three times as much carbohydrate as the classic ketogenic diet. The oil was mixed with at least twice its volume of skimmed milk, chilled, and sipped during the meal or incorporated into food. He tested it on twelve children and adolescents with intractable seizures. Most children improved in both seizure control and alertness, results that were similar to the classic ketogenic diet. Gastrointestinal upset was a problem, which led one patient to abandon the diet, but meals were easier to prepare and better accepted by the children. The MCT diet replaced the classic ketogenic diet in many hospitals, though some devised diets that were a combination of the two.
After about two to seven days of following this eating routine, you go into something called ketosis, or the state your body enters when it doesn't have enough carbs for your cells to use for energy. Then it starts making ketones, or organic compounds that your bod then uses in place of those missing carbs—and oh, it also burns fat for more energy, says Beth Warren, R.D., founder of Beth Warren Nutrition and author of Living A Real Life With Real Food.
A modified version of the ketogenic diet, which allows you to eat protein more liberally — at 20 to 30 percent of your total calories — with the same carbohydrate restriction, is the more commonly used version of the diet today. Some of the aims of the latest version of the ketogenic diet are weight loss, weight management, and improved athletic performance.
My numbers come out similar to yours. I’m confused about your daily menu example, though. I figure I can only eat 70g or 2 – 3 oz of meat per day. That is one very small piece of meat. But you show meat at every meal. Also, the fat requirement is about equal to one cup of lard. How do you do that if you’re on the go and want to, say, pack a quick lunch? Or if you’re traveling?
The ketogenic diet — a high-fat and very low-carb eating plan — can be tough to start. After all, it’s likely a radical departure from the way you’re eating now (a typical standard American diet is high in carbohydrates and processed foods). But many people are trying the keto diet, which puts your body in a state of ketosis. That's what happens when your body’s carb-burning switch flips to a fat-burning one, a change that can cause weight loss and has even been credited with controlling diabetes. (1)