The problem with burning mostly sugar is that it stops our bodies from burning fat by making the insulin hormone work. When you eat carbohydrates, your blood sugar and insulin levels rise. The hormone insulin, which tells the body to store fat, now tells the body to do so.
So, the fat is kept for later and the sugar is eaten first. The problem is, in a nutshell, that later never comes.
By drastically reducing the amount of carbs in your diet, you can get into and stay in ketosis, a metabolic state in which your body burns ketones as a very effective alternative fuel. Recent studies show that the keto diet seems to help with heart disease, type 2 diabetes, and Alzheimer's disease, in addition to helping people lose weight.
Even carbs with a high glycemic index, like bread and pasta, quickly break down in the gut to pure glucose, a simple sugar that raises blood sugar and insulin levels.
So, even starchy carbohydrates like bread, pasta, and rice break down in the gut into simple sugars.
So, people who eat the typical diet have sugar in their blood all the time. In the worst case, it could even cause them to get diabetes while they continue to store fat. Just eating less and moving more won't be enough to stop it.
It takes work to lose weight by watching how many calories you eat. It can be nearly impossible as long as people eat a lot of sugar or carbs while thinking they are being good. Because they will always be storing fat, and a bad diet is impossible to change. What does this have to do with keto, anyway?
The exact opposite is a ketogenic diet. We always use fat instead of sugar to get energy. Even though there are many healthy ways to eat, the ketogenic diet is the most effective way to treat problems like obesity that are caused by eating too much sugar and carbohydrates. We don't do it at all, instead of constantly eating sugar and carbs throughout the day.
The energy you need, which you used to get mostly from sugar or carbs, will now come from fat. Fat is a direct source of energy for all of the muscles in our bodies.
ketones are a terrific brain fuel. As a result, when you follow the keto diet, your brain will also burn fat. When you don't eat for a long time, especially if you're fasting or starving, your body quickly uses up any stored sugar and starts making ketones from fat to power your brain.
You will be burning fat constantly, even while you sleep. This is different from someone who might spend an hour on a treadmill to lose weight.