Most restaurants have started serving bigger portions over time. While it may seem like "getting more for you money" is good, your mind can trick you into eating more than your body needs.
If you’re an active teen guy, you need up to 3,200 calories per day. Active teen girls need up to 2,400. (Not active? You need 2,000-2,600.) When you get 610 of those calories from fries, you leave less room for more nutritious foods.
So keep in mind: A reasonable portion of fries is about the size of a baseball, or 10 fries.