On the other hand, being underweight may not pose a health risk and might merely be about improving appearance. Some people are born with fast metabolisms that burn calories quicker than they can eat them. In this case, your caloric intake is most probably providing your daily requirements for nutrition, and you’ll have to learn to eat more, more often, and eat more calorically dense foods to try to defy your genetics.

Seven Tips to Help You Pack in the Calories

Gaining weight requires devouring more calories than you burn. In fact, to gain one pound, you need an extra 3,500 calories coming from food. Naturally, that’s not at one sitting, but by simply eating an extra 500 calories a day, you can gain a pound per week—because 500 calories × 7 = 3,500 calories. Stick with the basic food principles and concentrate on the following tips:

Eat larger portions at your three main meals; even consider adding an extra meal to your day. Snacks are important! Plan at least three snacks a day. Tote along some trail mix, dried fruits, crackers, sports bars, fig bars, and nuts, or keep them in your desk at work. Add calorically dense foods to your meals. For example, toss beans, seeds, nuts, peas, avocado, cheese, and dressings into salads. Add shrimp, fish, chunks of chicken, and a lot of Parmesan cheese to pastas. Add crackers, rice, corn, noodles, and beans to your soups. Don’t forget the bread basket—spread on the margarine and dig in! Guzzle tons of pure fruit juice or milk (preferably 1-percent or 2-percent) with and between your meals; it’s a great way to painlessly add calories. Add powdered dry milk to your soups and casseroles. Try a calorically dense supplement, such as Ensure Plus, Sustacal, Boost, Carnation Instant Breakfast, and Nutriment. Just make sure you drink them between meals or with meals—not instead of meals. Consult a qualified exercise trainer about embarking on a weight-lifting program. It can help you build muscles and put on some pounds.