What is ketosis?

Erin Palinski
Nutrition & Dietetics
When we drastically restrict our carbohydrate intake, our body's main source of energy is depleted. Our body then must turn to protein and fat as energy sources. This leads to a state of "ketosis," which is a biochemical condition where the body produces ketones (fat fragments) at a higher rate than it releases glucose into the blood. Ketones are the result of the breakdown of fat, supporting the claims that a low-carbohydrate diet results in the burning of fat.

However, ketones, although not the preferred energy source for the body, still provide 5 calories per gram to the body. This is higher than the 4 calories per gram provided by carbohydrate. The difference lies in the amount absorbed. Since carbohydrates are more easily absorbed than ketones, more will be converted to energy for the body to use and store. However, at the end of the day, if 90% of carbohydrates and 70% of ketones consumed are converted to energy by the body, there is not a large difference in calorie savings.

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