The problem of being underweight has become a common phenomenon. It is a condition, when a person does not have an ideal weight, according to his/her height and sex. A person, who weighs almost 10 to 20 percent below the average, is termed underweight. Some of the causes for underweight problems are rise in the stress level, lack of sleep, poor nutrition, exposure to pollutants, lack of exercise, etc. Bad eating habits also add to the causes for the occurrence of the problem. Being underweight can also arise due to hereditary reasons. Apart from being skinny, a person starts facing a number of health problems. However, gaining weight is not as major problem and can be treated by indulging in the right kind of eating habit. In the following lines, we provide some of the ways to gain weight.