It's not so much the number of meals you need to eat a day to gain weight but the number of calories. That said, because you need to eat more calories in order to gain, eating more often might help you take in enough calories without feeling too full at your meals.

Being too thin seems an enviable condition, given the rate of overweight and obesity in today's society. But with this unhealthy weight comes a host of potential complications. In addition to your not feeling your best, your body may not be able to perform optimally and compromise your health.

While a 2,000-calorie diet likely won't be enough for weight gain if you're young or very active, it can allow you to eat enough extra calories for safe weight gain if you're older, a woman, or you live a relatively inactive lifestyle.

While it would be nice to eat your way to an hourglass figure, no food has the power to give you a bigger butt or breasts. Gaining weight can increase the size of your chest and booty -- but it'll also make you gain weight in other areas, and where you gain weight comes down primarily to genetics.

Your friends may consider you lucky, but you may not feel that way if you're super skinny. If you're hoping to put on a few pounds, simply eating more isn't all there is to it. For healthy weight gain, you need to eat the right foods and find time to work your muscles, too.

Rapid weight gain has many causes, including hormonal changes, medication side effects and lifestyle changes. Even when trying to gain weight, a gain of more than one to two pounds a week is considered rapid and may be cause for concern.

Weight gain can help improve your performance in certain sports or fill you out so your physique matches that of other guys at school. Take in more calories than you burn daily to put on pounds -- but not just any calories.

Gaining weight while controlling your blood sugar can be very difficult for those with diabetes. The key to a healthy weight gain is to recognize which foods affect your blood sugar and which do not. For weight gain that also allows consistent blood sugar control, add more healthy fats to your diet.

Because your child is still growing, her weight-gain program will be different than a plan for an adult. Children need to eat enough calories and a balance of nutrients to support their normal growth and development, plus a bit extra to add weight to their frame.

Gaining weight to improve your football performance requires you to add muscle, not fat. A combination of strength training and consuming more calories encourages this lean mass development, but it's not easy. Filling up on extra fast food or junk food makes you gain fat, which will only slow you down out on the field.

If you have a high metabolism or are recovering from illness, or if you're an older adult with little appetite, gaining weight can be as challenging as losing weight. It's best to gain weight at a moderate rate to ensure that you're not adding too much body fat and are putting on a fair amount of healthy muscle.

Eating more to gain weight is difficult if your cupboards are bare. Go to the grocery store to stock up on healthy, nutritious and calorie-dense foods.