6. (Science: geometry) The formation or production of any geometrical magnitude, as a line, a surface, a solid, by the motion, in accordance with a mathematical law, of a point or a magnitude; as, the generation of a line or curve by the motion of a point, of a surface by a line, a sphere by a semicircle, etc.
Your weight is a balancing act, but the equation is simple: If you eat more calories than you burn, you gain weight. Because 3,500 calories equals about 1 pound (0.45 kilogram) of fat, you need to burn 3,500 calories more than you take in to lose 1 pound. So, in general, if you cut 500 calories from your typical diet each day, you'd lose about 1 pound a week (500 calories x 7 days = 3,500 calories). It isn't quite this simple, however, and you usually lose a combination of fat, lean tissue and water.
Calories can come from carbs, fat and protein. Your body can use them to fuel work right away, or store them for later use. Some calories can be stored as glycogen (carbs), but the majority is stored as body fat. This article explains how many calories are in a pound of body fat.