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How to Gain Weight: 13 Foods to Help You Add Pounds if You’re Underweight

If you're underweight—or are dropping pounds for no clear reason—your first stop should be a doctor’s office. If you get the green light that you need to eat more, here’s what nutritionists recommend for gaining weight.

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Potatoes

It probably comes as no surprise that potatoes are an all-star food for those who want to know how to gain weight. Jessica Rosen, a certified holistic health coach and cofounder of Raw Generation, explains that the starchy, carb-loaded tubers are quickly digested, which causes them to create a spike in the hormone insulin. The carbs are converted to glucose, which your body uses for energy. Any glucose your body can’t use will be converted into fat, helping you pack on the pounds. Potatoes are also a great source of potassium and vitamin C. 

rows of different dried fruit: figs, apricots, cranberries, raisinsnada54/Shutterstock

Dried fruit

Taking the water out of your favorite fruit concentrates its nutrients and sugars, explains Jill Weisenberger, RDN, author of Prediabetes: A Complete Guide. If you want to put on pounds, she recommends using dried fruit as a calorie-dense topping for yogurt, salads, meat, and grains. Check out the 8 subtle signs you’re eating too much bad fat.

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Avocados

Trendy and delicious, avocados turn up on toast, in scrambles, in BLTs, and, of course, as guacamole dips. Thanks to their substantial levels of monounsaturated fats, they should be part of any healthy plan for how to gain weight. Kaleigh McMordie, RDN, a dietitian in Lubbuck, Texas, recommends eating plenty of avocados if you want to pack on the pounds. Learn more about the 7 powerhouse benefits of avocados.

bananasEvlakhov Valeriy/Shutterstock

Bananas

As a snack or post-workout replenisher, it’s hard to beat a banana—and it’s unlikely to add pounds to your frame. However, says Rosen, if you down several a day, you’ll start to gain weight. Bananas have more calories and sugar than most other fruits. “Bananas are great for digestive health as well as mood and sleep regulation,” she says. “A good way to consume bananas for weight gain is to add them to your protein smoothies.” Learn more about the health benefits of bananas.

swirl of creamy peanut butterMaraZe/Shutterstock

Peanut butter

Actually, any sort of nut butter is helpful in boosting your overall body weight, according to McMordie. In moderation, peanut butter can help you maintain your weight; but snack on it—or other nut butter—throughout the day, says McMordie, and the mono- and polyunsaturated fats will boost the number on the scale. Plus, you’ll also be getting good amounts of fiber, magnesium, and protein. Know the 7 clear signs you’re not eating enough healthy fats.

stacks of different cheesesAfrica Studio/Shutterstock

Cheese

Here’s excellent news if you’re the type who would prefer cheese over a cheesecake: Keith-Thomas Ayoob, RDN, a clinical associate professor at Albert Einstein College of Medicine in New York City, explains that most cheeses have around 110 calories per ounce, tons of calcium, and up to 8 grams of protein, making them a healthy weight-gain winner. “Hard cheeses have the most calories, but soft cheeses can be helpful in larger quantities,” he explains.

Almonds, walnuts, pistachios

Ayoob says that specific nuts like almonds, walnuts, and pistachios are weight-gaining standouts. “Almonds have a good dose of fiber, plus lots of heart-healthy unsaturated fats. The same for pistachios—and an ounce of either also gives you about six grams of protein, the same amount you would get in an egg. Walnuts are high in omega-3 fats, which are excellent for heart health,” he explains. Each of these nut varieties delivers about 160 calories per ounce (about a handful). Read about these 7 other ways to get healthy doses of omega-3 fatty acids.

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Fruit juice

If you’re trying to gain weight, consider the calorie content of 100 percent fruit juice. Because it can be dense in numbers but also in nutrients, Weisenberger says it’s a smart way to pack on pounds. Her best suggestion is to trade a few glasses of water for a few glasses of juice. 

shelled peanutsStepanPopov/Shutterstock

Peanuts

Despite the name, peanuts are more closely related to beans—they’re in the legume family, and they grow in the ground, not on trees. For heavy exercisers who need plenty of energy to maintain their weight and their demanding schedule, the concentrated calories of peanuts make them an excellent snack choice. “Peanuts, either roasted and eaten out of hand or as peanut butter, are pretty economical, as nuts go, and an ounce gives you seven grams of protein,” Ayoob explains. Learn more about the healthiest nuts you can eat.

mason jar with green smoothie topped with chia seedsotarikokojevs/Shutterstock

Smoothies

While the idea seems healthy, you can squeeze a ton of calories into these liquid meals. “Smoothies are easy to make calorie- and nutrient-dense without being too filling for those looking to gain weight,” McMordie explains. “Adding nut butter, avocado protein powder, seeds like flax or chia, oats, and full-fat milk can help add more calories and nutrition to smoothies.” You may want to try these 7 breakfast fruit smoothies.

dried nuts, seeds, and craberriesiStock/jatrax

Trail mix

This mix of weight-gaining superstars—nuts and dried fruits—makes a particularly effective snack for those looking for strategies on how to gain weight. “The nuts are loaded with healthy fat, and both nuts and dried fruit have concentrated calories while also being loaded with antioxidants, vitamins, minerals, and fiber,” says Ayoob. Learn more about 5 healthy fats you should eat.

swirled plain yogurtInes Behrens-Kunkel/Shutterstock

Whole-milk Greek yogurt

Greek yogurt has just as much protein as the nonfat option, but far more calories. Since you’re looking for advice on how to gain weight, having a cup or two of this with walnuts, dried dates, honey, and fruit is an effective way to achieve your goals, according to Ayoob. If you’re lactose intolerant, you can substitute almond-milk yogurt.

cut of raw marbled beefrainieC/Shutterstock

Beef

As long as you’re still a carnivore, it’s hard to beat beef’s combo of fat, protein, and iron. Ayoob explains that a healthy cut of beef can help your body produce red blood cells, deliver oxygen and nutrients to the muscle tissue, and support your goal of weight gain. “Treat yourself to a great steak and round the meal out with a big green salad dressed with olive oil and balsamic vinegar,” he says. For an added boost, throw some nuts and beans into the salad. Now read about 20 reasons for unexplained weight loss.

Sources
Medically reviewed by Elisabetta Politi, CDE, MPH, RD, on October 20, 2019