Currently with the massive load of cabohydrates in our foods, our bodies are conditioned to burn carbs for energy instead of fat.
Its hard to get and stay in Ketosis!
If you've tried a keto diet, then you know it takes discipline! It can take up to a week with the "Keto Flu" to get into full Ketosis.
In the state of ketosis, the body can switch its fuel source and increase the potential to use stored fat.