We are all born as fat burners, but modern western diet and eating pattern has converted most people into fat storing, carb dependent sugar burners. The fantastic human capability to store subcutaneous body fat as an internal mobile energy supply for later use when needed, is evolutionary created as a zero-sum process in a time when food availability could vary a lot with changing seasons and weather conditions. It was crucial to be capable to perform at maximum both physically and mentally on an empty stomach to get enough food to survive. Today's constant food availability and frequent eating and snacking has made this delicate process go totally out of balance, resulting in that the amount of energy that is stored as body fat is too often higher than the energy that is burned. Almost constantly having food in the digestive system also signals to the brain that metabolic and anabolic hormonal processes and production are no longer important to keep up to survive.The capability to effectively release ketones from stored body fat for energy becomes almost deactivated, since the easiest way for your body is to use sugar in the blood stream from food you just ate. This process creates a negative spiral, making you dependent on frequent eating and snacking to keep energy levels up and prevent blood sugar fall and bad mood. It also creates insulin resistance and sets your  "metabolic switch"  in almost constant storage mode, regardless of how little you eat. This is the main reason behind the gradual increase in fat percent most people experience after adolescence and why obesity is one of the biggest health problems we have today!