The human body is a remarkable food processor. As an , you may consume (36) a ton of food per year and still not gain or lose a pound of body weight. You are (37) harnessing and consuming energy through the intricate (38) of your body in order to remain in energy balance. To (39) a given body weight, your energy input must balance your energy output. How ever, sometimes the (40) energy balance is upset, and your (41) body weight will either fall or (42) . The term body image refers to the mental image we have of our own physical appearance, and (43) . Research has revealed that about 40 percent of men and 55 percent of women are dissatisfied with their current body weight. (44) . At the college level, a study found that 85 percent of both male and female first-year students desired to change their body weight. (45) . Thinness is currently an attribute that females desire highly. Males generally desire muscularity. (46) who want to change their body weight do it for the sake of appearance; most want to lose excess body fat, while a smaller percentage of individuals actually want to gain weight.