If you're naturally thin and underweight, putting on pounds can be a challenge. Whole foods are your best choice when adding calories because they offer nutrients, fiber and no added chemicals or preservatives. When you aren't able to whip up a meal, the convenience of a supplement is hard to beat. Look for food-based options that are the least refined, and avoid those packed with added sugars, preservatives and additives that won't help you meet your goals.
How You Gain Weight
A surplus of calories -- eating more calories than you burn -- is key to gaining weight. Use an online calculator or speak with a dietitian to determine how many calories you need each day to maintain your weight. Then add 250 to 500 calories to that number for a healthy 1/2 to 1 pound of weight gain per week. Increased portion sizes at meals help you boost calorie intake, but so can regular snacks between meals and before bed.
To ensure you gain muscle and not just fat, exercise -- especially strength training -- is also essential. After a workout, eat a snack that contains carbohydrates -- to help restore energy -- and protein to assist with muscle growth and repair. Getting these nutrients from food is better than getting them from supplements. Consumer Reports found in 2010 that some of these weight-gain supplements contain unregulated ingredients as well as steroids and prescription drugs.
Whole Food Bars for Weight Gain
A baggie of nuts or dried fruit serves as a good between-meal snack, but sometimes you want something that's even easier to grab and eat on the go. Look for whole-food bars that combine dried fruit, such as dates, and mashed nuts, with no added sugar. Some include other healthy, high-calorie ingredients such as chia seeds, coconut oil and oats. Bars usually provide a 200- to 300-calorie boost to your calorie intake.
For a post-workout boost, look for a bar that also contains 10 to 20 grams of high-quality protein. Good protein ingredients include whey, quinoa or soy protein, or even meat -- jerky-style. Bars with added sugar or corn syrup as the first ingredient are less likely to provide you with quality calories, and they'll significantly up your sugar intake.
Homemade Shakes for Weight Gain
Liquid calories go down easily, especially if you have a job or schedule that doesn't give you a lot of time to eat between meals. Make your own high-quality shakes with high-calorie, nutrient-rich ingredients such as nut butter, bananas, chia or flax seeds and canned, unsweetened coconut milk. For example, natural medicine guru Chris Kresser gained weight drinking a daily breakfast shake that contained more than 1,000 calories from a mixture of whole milk, whole yogurt, coconut oil, berries and raw egg yolks -- from pasteurized eggs only, to avoid foodborne illness.
Such a nutrient-rich shake is appropriate post workout as it provides protein and carbohydrates. If you are looking for a more modest boost of calories from a shake, make one with a minimally processed whey protein, yogurt and fresh fruit. Although whey isn't technically a whole food -- it's highly refined from dairy -- you may choose to use it as a convenient, occasional shake ingredient. Look for a whey powder that's cold-filtered and free of artificial sweeteners, added oils and unregulated supplements.
Weight Gain Drinks as Supplements
Your doctor may recommend you take a pre-packaged nutrient-rich shake to add calories. In an 8-ounce serving, you'll get between 200 and 300 calories and 10 grams of protein as well as an array of added vitamins and minerals -- depending on the brand. These drinks can be high in added sugar, however. If you have an underlying condition, such as diabetes, talk to your doctor before including them in your diet.
Double-strength milk -- made by dissolving milk powder into fluid milk -- is another way to increase your calorie intake. Dried whole milk powder contains 159 calories and 8 grams of protein per 1/4 cup. Stir it into a cup of liquid whole milk -- which has 149 calories and 8 grams of protein -- for a hefty calorie-boost. Dried milk could also be added to smoothies, casseroles, cooked cereal and creamy soups.