Advocates of ketogenic diets for weight loss claim that ketogenesis can lead to burning 10 times more fat and an extra 400 to 600 calories per day.This might sound great, but what’s often lost in all the boosterism is that this is still just a hypothesis.

The "metabolic advantage" hypothesis

It supplies energy under circumstances such as fasting or caloric restriction to certain organs (e.g. the brain, heart, and skeletal muscle).In ketogenesis, our livers start to break down fat into a usable energy source called ketones. Ketones can stand in for glucose as fuel for the body when there’s a glucose shortage. Once ketogenesis kicks in and ketone levels are elevated, the body is in a state called “ketosis,” during which it’s burning stored fat.

The Ketogenesis process

Doctors have been prescribing ketogenic diets to treat epilepsy for nearly a century, and increasingly believe it holds promise for people with Type 2 diabetes.But the older keto regimens didn’t work for most people hoping to slim down, and there’s no evidence the newly popular keto diet will be any different.

Documented uses of the keto diet

It is a very low-carb, high-fat diet. People on a ketogenic diet get 5 percent of their calories from carbohydrates, about 15 percent from protein, and 80 percent from fat. It’s this ratio that will force the body to derive much of its energy from ketones. That means eating mainly meats, eggs, cheese, fish, nuts, butter, oils, and vegetables while avoiding sugar, bread and other grains, beans, and even fruit.

The Keto diet

Keto diets don’t seem to help people lose extra weight in the long run.In the short term, keto can sometimes help people lose more weight because they cause rapid water loss, which gives people the impression they’ve lost fat. But by the one-year mark, it performs equally to any other weight loss diet.

Keto in the long run

It's why people are putting grass-fed butter in their coffee, downing ketone drinks, and replacing their cereal and pasta with eggs and avocados. The ketogenic diet has become a Silicon Valley obsession and the diet du jour that supposedly keeps celebrities like Kim Kardashian and Halle Berry trim and strong.