An apple a day not only keeps the doctor away, apply also helps supercharge your fat metabolism. It is full of soluble fiber called pectin which keeps you feeling full and your appetite in check. Pectin also has the ability to limit the fat absorbed by body cells. Therefore, an apple eaten before a meal is likely to limit the amount of fat absorbed into your body.Apples also contain polyphenols and fiber which cannot be digested. In the colon, they ferment and are the nutrients for good bacteria in the body. A balance in the microbial environment in the body boosts the feeling of fullness and reduces the risk of obesity.