You probably know the food pyramid well enough. It is a food pyramid with horizontal stripes ( 水平线 ).Carbohydrates( 碳水化合物 ),such as bread ,rice and potatoes ,are on the base of the pyramid .They are most of our everyday food .The fats and oils are at the top of the pyramid. We should eat the least of them. Well, the food pyramid with vertical stripes( 垂直线 ). Instead of the horizontal stripes ,the vertical stripes mean the five food groups and fats and oils .This is because not all foods in a food group give us the same health benefits .A fresh apple ,for example ,would be on the base of the pyramid ,while an apple pie would be at the top. This shows that we can eat more steps going up the side. This shows us how important exercise is .It also shows us that we will be healthier and healthier if we take exercise every day. So why did some American experts change the pyramid? They did this to do a better job of telling people how to be healthy .The new pyramid tells us to have balanced ( 平衡的 )food from each food group every day and it shows us that we need less of some kinds of food than other s , For example ,you need less meat or fish than rice or fruit .It also shows us that not all foods in a group give us the same health benefits, and that exercise is quite important in our everyday life.