Sugar tastes oh so sweet, but do we really need it? And is that spare tire around your waist, your neck jowls and upper arm flab caused by eating too much sugar? Research in recent years has shown that your sugar intake can have a definite effect on your body weight, over time. So how much is too much, and just exactly how does sugar make you fat? Let's take that second question first. Sugar, as well as high fructose corn syrup, is made up of glucose and fructose. You need glucose to live. Your body produces it naturally, and it is used to give your cells energy. But fructose is unnatural, and your body does not produce it. Of all the cells in your body, only your liver cells can process fructose. When you eat a lot of sugar, the majority of fructose gets metabolized by your liver. It is processed and turned into fat, which is in pushed out into your blood. Fructose also changes the way you react to a hormone called leptin. Every time you eat, some of your food is stored in your