The aim is far broader than suggested by the article here: It’s not just about what you put in your mouth – it’s also about timing and exercise. There are three ways to be in ketosis – which simply means that “fat burning” and not being dependent on sugars. Fasting puts a man into ketosis in 3 days and a woman by 2 days. Endurance exercise gets you there in a couple of hours. Eating a high fat diet will do it too. The goal however is hidden by the detail – it is to acquire a “Flexible Metabolism”. The aim is to switch on the full fat burning capacity and keep it running – which takes from between 4 to 12 weeks physical adaptation (for the muscles to fully be able to use ketones). The heart runs approximately 27% more efficiently on ketones than on glucose! The brain works better too – Alzheimer’s being referred to by researchers as “diabetes 3”. Once you have a Flexible Metabolism you can consume carbs during or after exercise without dropping out of ketosis – though this depends on your own bio-individuality. I can eat quite a lot of carbs – without losing ketosis – my partner cannot.
The ketogenic diet tries to bring carbohydrates down to less than 5 percent of a person’s daily caloric intake – which means eliminating most grains, fruit, starchy vegetables, legumes and sweets. Instead, it replaces those calories with fat. That fat is turned into ketone bodies, which are an alternative energy source: besides glucose derived from carbohydrates, ketones from fat are the only fuel the brain can use.
On a ketogenic diet, your entire body switches its fuel supply to run mostly on fat, burning fat 24-7. When insulin levels become very low, fat burning can increase dramatically. It becomes easier to access your fat stores to burn them off. This is great if you’re trying to lose weight, but there are also other less obvious benefits, such as less hunger and a steady supply of energy. This may help keep you alert and focused.