While you likely hear more about the risks of carrying too much body weight than about carrying too little, being underweight can negatively affect your health, too. People who are underweight are more likely to face fertility issues and have slower recovery after illness and a higher risk of complications from medical procedures. You don't need any fancy tricks or dietary supplements to gain weight, although if you want to use them, they may help. Just up your calorie intake, and you'll gain pounds.
Create a Calorie Surplus
The first rule of gaining weight makes or breaks your weight gain plan: If you don't create a calorie surplus by consuming more calories than you burn, you won't gain weight. You don't need thousands of excess calories through; just 250 to 500 extra calories daily allow you to gain 0.5 to 1 pound weekly. Start your weight gain journey by consulting a nutrition professional to figure out how many calories you currently burn, or use an online calculator to estimate this figure, based on your age, body size and gender; then add the extra calories to create your surplus.
Get Quality Protein
Make high-quality protein part of your diet to gain weight. Protein supports muscle tissue, and following a diet high enough in protein can help support muscle gains, as long as you pair your diet with a strength-training exercise program. To calculate your protein needs for weight gain when you're strength training, multiply your weight, in pounds, by 0.6 to 0.8 to get the protein grams you need daily. For instance, a 110-pound person needs 66 to 88 grams of protein per day. Then include protein at each meal; you could serve scrambled eggs at breakfast, enjoy a Greek yogurt with your lunch, snack on a protein shake, and serve grilled chicken breast at dinner. If you suffer from kidney disease, though, this amount of protein may be too much, so check with your doctor for dietary recommendations.
Fuel Up With Carbs
Carbs should also make up a significant part of your diet. At 4 calories per gram, they supply energy to power your muscles, brain and other tissues through your day-to-day activities, and they can also help you feel energized for weight gain-inducing strength workouts. Enjoy generous portions of healthy carbohydrates to gain weight the healthy way; eat whole-grain bread, whole-wheat pasta, quinoa, oatmeal, brown rice and foods that contain healthy natural sugar, like fruit and milk.
Add Healthy Fats
Adding fat to your diet is an easy way to gain weight; each gram of fat boasts 9 calories per gram, which makes fat a concentrated source of energy. Fat also adds flavor to your food, so you can enjoy your weight gain diet. Steer clear of processed foods, which are often high in artery-clogging saturated and trans fats. Instead, get your fats from unsaturated fats, like those found in fish and plant-based oils. A tablespoon of olive oil, for example, contains 124 calories, while the same size serving of coconut oil offers 121 calories.
Enjoy High-Calorie Snacks
If you aren't already snacking, start. Snacks boost your nutrient intake, and they can help increase your overall calorie intake to support weight gain. Try snacking on an ounce of macadamia nuts for a weight gain boost -- 1 ounce has 201 calories. Other nuts, including pecans and peanuts, offer a significant amount of calories, too. If you don't eat nuts, try high-calorie dried fruit. A half cup of dried apricots or dried peaches contains 191 and 189 calories, respectively. Snack on a half cup of golden raisins, and you'll boost your calorie intake by 219 calories.
Drink Your Calories
Liquid calories aren't necessarily as filling as solid food, so they're an easy way to gain weight. Enjoy calorie-rich beverages, including juice, milk and fruit smoothies. Pack your smoothies with extra calories by adding energy-dense ingredients like peanut butter, which contains 188 calories per 2-tablespoon serving. Blending your smoothie with a 5.3-ounce container of Greek yogurt to add 159 calories to your meal.
If you're looking to pack on muscle, blending protein powder into your smoothies can help. One variety of whey protein powder supplies about 100 calories and 17 grams of protein per scoop. However, high-protein powders and shakes aren't suitable for everyone, so get your doctor's permission before consuming them.
Try Higher-Calorie Substitutions
Swapping out a higher-calorie ingredient for a lower-calorie one is a simple way to get more calories. Because you're not changing the size of your meal, just the calorie count, you're less likely to feel too full. Try using full-fat options instead of lower-calorie fat-free options. Make your smoothie with whole milk or chocolate milk, for instance, to get 149 or 208 calories per cup -- significantly more than the meager 83 calories in nonfat milk. Or use high-calorie avocado in your sandwiches, wraps and salads in place of lower-calorie veggies, like tomatoes.
Strength Train for Muscle Gain
Strength training helps ensure part of your weight gain comes from muscle, not just from fat. If your doctor has given you clearance to strength train, start building muscle with large movements that work several muscles at a time -- like pushups, deadlifts and squats. If you're a beginner, performing these workouts using just your body weight will be enough for muscle growth; as you get more advanced, you can start adding weights, like dumbbells.
Do Cardio to Stay Healthy
Don't worry; you won't need to spend hours on the treadmill. However, some aerobic exercise will help you avoid gaining too much fat, which can keep you looking lean and healthy, and it will benefit your heart. Just 150 minutes weekly is enough moderate aerobic activity to maintain your health, according to the CDC. If you're doing vigorous cardio -- like running, rowing or swimming laps -- you can cut that down to 75 minutes. Doing cardio may also rev your appetite, so you're inclined to eat more.
Try Weight Gain Supplements
You don't need weight gain supplements to put on pounds, notes North Carolina State University. However, if you want to use them, they can help you achieve your weight gain goals. Regular protein powders can supply 150 to 300 or more calories per serving, while special powders specifically designed for weight gain can have 1,000 calories per serving, or more. If you're having trouble meeting your calorie goals, a weight gainer might help. However, weight gainers can cause side effects in some people, similar to protein powder, so talk to your doctor before trying one.