Some people are simply hard gainers. There is no magic solution to the problem. If your parents or grandparents looked like you when they were your age, you may have a body build and weight range that has been largely predetermined. Even if genetics are not responsible for you being the way you are, the inability to gain weight easily could be blamed on a supersonic metabolic consume.

Eat
Eat three hearty meals plus one or two snacks everyday. You may not feel hungry for lunch if you've had a big breakfast, but you should eat regardless. Otherwise, you'll miss out on important calories that you needs to accomplish your goal. Eat larger portions, like a bigger bowl of cereal, a larger piece of fruit, an extra-large sub sandwich, or a taller glass of milk. Choose foods that are higher in calories, but not in fat. Extra carbohydrates provide energy for exercise. Here are some examples:

Food /	Amount /	Calories Instead of /	Calories
Grape-Nuts /	1.5 cups /	660 Cheerios /	160
Granola /	1.5 cups /	780 Bran Flakes /	200
Baked Beans /	1 cup /	260 Rice /	190
Cranberry Juice /	8 oz /	170 Orange Juice /	110
Grape Juice /	8 oz /	160 Grapefruit Juice /	100
Corn /	1 cup /	140 Green Beans /	40

Drink
Drink lots of juice and low-fat milk. Instead of drinking primarily water, quench your thirst with calorie-containing fluids. Extra juices are a great source of calories and carbohydrate. Bulk up. Don't fatten up. With the increase in calorie intake, it's important to start a strength training program. The more you exercise, the more you will want to eat. Finally, be patient. Things change with age and you might begin putting on wanted pounds as you get older. And remember this: most people would love to have your problem.