The term convection generally refers to the movement of fluids, meaning liquids and gases, but in the earth sciences, convection also can be used to describe processes that occur in the solid earth. This geologic convection, as it is known, drives the plate movement that is one of the key aspects of plate tectonics.
The recommended range is 45 â 65% of calories as carbohydrate. For example, if you eat 1600 calories per day, and 50% of those calories are carbohydrate, you would eat 200 grams per day. Athletes need to eat at the high end of the carbohydrate range, to fuel training and competition.
Calories aren't bad for you. Your body needs calories for energy. But eating too many calories â and not burning enough of them off through activity â can lead to weight gain. Most foods and drinks contain calories. Some foods, such as lettuce, contain few calories (1 cup of shredded lettuce has less than 10 calories). Other foods, like peanuts, contain a lot of calories (Â½ cup of peanuts has 427 calories). You can find out how many calories are in a food by looking at the nutrition facts label.