Appeton Weight Gain (Adult), a scientifically formulated milk formula manufactured to help skinny adult to gain weight in a healthy and natural way. Why are some adults underweight? There are many reasons why adults are underweight. Most adult are skinny genetically where they have higher metabolism rate compare to others. Busy lifestyle with stress, depression, smoking, poor appetite, convalescence or strenuous physical activities are part of the reason why most adult stay skinny. Among ladies especially, image might be another possible cause of poor eating habits. The influences from the TV commercial, image of slim is beauty, cultural, public talk, trendy and etc pressure girls and even guys to stay slim. In serious cases, they become obsessed with losing weight and run the risk of becoming anorexic.