Because of the effects food has on our body, it doesn’t just matter how many calories you eat, but what you eat. The hormone that acts in opposition to insulin is called glucagon. Where you want to keep insulin as low as possible, due to its fat-storage effects, you want to keep glucagon levels high, because it mobilizes fat from storage. Whenever you eat a high sugar food or refined carbohydrates (e.g. white bread) your blood sugar spikes, causing insulin to spike and glucagon to be low. Therefore, you want to eat as little sugar as possible.
This is important if you want a flat tummy. Chewing your food throroughly is an incredibly easy and effective way to avoid bloating. You should be chewing your food until you can no longer identify what you’re eating by its texture. Chewing tells the rest of your digestive system (stomach & intestines) to start the digestive process. Chewing thoroughly also breaks down the food into finer particles and means that it can be broken down and absorbed better in your gut. If you don’t chew sufficiently, the food isn’t fine enough to be digested, meaning the food remains only partially digested. The undigested food is pounced on by the “bad” bacteria in the colon, which can lead to bacterial overgrowth, flatulence and other symptoms of indigestion.