Today, many people on the Internet are urging people to eat a “keto” diet. A keto diet is so high in fat and so low in carbohydrates that it causes people to go into a state of ketosis. Ketosis means that “ketone bodies” have built up in the bloodstream. Ketone bodies are chemicals that are produced by an alternative method of burning fat. Ketosis does not mean that you are losing weight. It really just means that your liver is turning a lot of protein and other noncarbohydrates to sugar. No human society has ever eaten a ketogenic diet. So the long-term safety of ketogenic diets is questionable.
The real Paleo diet was not keto
Many people claim that the keto diet is the natural diet that people ate during the early stone age (Paleolithic era). However, most people in the stone age would have eaten a heavily plant-based diet. They would have gotten a lot of their calories from starchy plant material, such as roots and tubers. In fact, anthropologists have been finding starch grains in the tartar of the teeth of Paleolithic skeletons.
It is easy and safe to dig up roots and tubers. In contrast, it is hard and dangerous to kill big animals. Also, you can dig up a lot of roots and tubers in the time it takes to catch a fish. As a result, stone age people would have gotten more than enough carbohydrate to keep them from going into ketosis.
Even the Inuit did not eat a keto diet
Even the Inuit’s (Eskimos’) traditional winter diet of fatty meats and fish did not produce ketosis. Studies done in the early 20th century found that the Inuit did not get ketosis unless they were fasting. The Inuit were eating raw meat. Some of their meat was fresh-killed. The rest had frozen immediately after being killed. Unlike the meat you would buy at a supermarket, this fresh or rapidly frozen meat still contained a starch called glycogen. The Inuit also used a method of meat preservation that converted some protein to sugar. As a result, the Inuit’s traditional diet contained a surprisingly large amount of carbohydrate: enough to keep people out of ketosis.
Low-carb diets cause rapid aging, early death
It is good that the Inuit diet did not cause ketosis. The Inuit already had extremely high rates of osteoporosis, because of the metabolic acidosis caused by their high-protein diet. Adding even more acid, in the form of ketone bodies, would have made this problem even worse. Eating a lot of calcium, in the form of fish bones, did not solve this problem. In fact, high-calcium diets actually increase your risk for osteoporosis.
Ketosis does not mean weight loss
Some “Paleo” advocates claim that ketosis means that you are burning fat and are therefore losing weight. Some of them even claim that you cannot lose weight or burn fat unless you are in ketosis, which is total nonsense. The Krebs cycle, which is the body’s normal way of burning fat, does not produce ketone bodies. Having ketones in your urine does not even guarantee that you are losing weight. To lose weight, even on a ketogenic diet, you must burn up more calories than you take in. Even on a ketogenic diet, you can still gain weight. The burst of insulin that is released in response to eating foods that contain protein could drive excess fat from the food into the fat cells.
Ketosis means that your liver is making a lot of sugar
The ketosis does not mean that you are losing weight. It is simply a sign that your liver is making sugar (glucose) out of proteins and other noncarbohydrates. Your liver is working so hard to make this glucose that it is using up one of the chemicals that it needs for burning fat completely. As a result, some of the fat gets broken down through an abnormal pathway that produces ketone bodies.
Is ketosis harmful?
During a fast, a little bit of ketosis is good. Your brain can use a little bit of the ketone bodies as an alternative fuel. However, the severe ketosis that can occur in untreated type 1 diabetes is a life-threatening emergency. Before the discovery of insulin, type 1 diabetes always led to ketoacidosis, coma, and death. Ketoacidosis means that the ketosis is so bad that it lowers the blood pH. Diabetic ketoacidosis is a combination of high blood sugar, dehydration, low blood pH, and an electrolyte imbalance. These problems must be corrected carefully, at the same time, in an intensive care unit.
In a healthy person, the ketone levels in the blood are usually less than 1 mg/dL. Normally, the ketone body concentration in urine is too low to show up on a test strip. You can boost your production of ketone bodies by fasting or by eating a low-carbohydrate diet. You can get into a state of ketosis either way. However, the effects of a fast are far different from the effects of a low-carbohydrate diet. The Paleo advocates believe that eating bacon and eggs—but no toast—would produce the same effect as fasting. It is a foolish belief.
Scientists are only beginning to understand the potential benefits of periodic fasting. Fasting is a sure-fire way to lose some weight. Fasting can also help to suppress a runaway inflammatory response. A medically supervised water-only fast is also a useful first step in an elimination diet. The goal of an elimination diet is to identify which foods are making you sick.
Should you believe the Paleo hype?
Many people swear by the Paleo diet. They claim to have eaten it for months or even years. They claim that it made them thin and healthy. Yet there is room for doubt. No societies anywhere on earth have eaten a ketogenic diet. Also, the societies with a high-fat, low-carb diet have rapid aging and a short life span. In contrast, the people who eat a high-carbohydrate diet based on starches and vegetables can have long and healthy lives. The China-Cornell Oxford Project found that the less animal-source food a population eats, the lower its average cholesterol level is and the lower its risk of death from chronic disease is. Eating even small amounts of animal-source food is dangerous.
The side effects of the keto diet
A ketogenic diet can suppress seizures in children with severe epilepsy. Yet in those children, the diet can have side effects. It can cause dehydration, constipation, vomiting, high cholesterol, and kidney stones. Some children have had severe side effects. These include heart rhythm problems, inflammation of the pancreas, and loss of calcium from the bones. In short, a ketogenic diet is useful for managing some rare but serious diseases. However, the keto diet s dangerous in the long run.