How Many Calories Do I Need to Eat to Gain a Pound?

Your friends may wish they had your problem, but adding a pound is as hard for you as it is for them to lose one. To add extra pounds, you need to eat more calories. However, there's no hard and fast rule for the number of extra calories you need to gain a pound. Healthy weight gain requires a change in how you eat, as well as how you move. To discuss a personalized diet and exercise plan to meet your specific needs, consult a registered dietitian.

An extra handful of peanuts a day may be all you need to gain 1 pound in a month. (Image: 5PH/iStock/Getty Images)

The 3,500-Calorie Rule

It's generally understood that 1 pound contains 3,500 calories. Logically, eating an extra 3,500 calories, or 500 more calories each day for a week, will lead to a 1-pound weight gain. While the 3,500-calorie rule is used by health-care professionals to help promote both weight gain and loss, and may be a good place to start, weight gain isn't that simple.

There are a number of factors that may affect your specific weight-gaining calorie needs, including gender, body composition, metabolic rate and your daily activity. While eating an extra 500 calories a day may help you gain a pound, your calorie needs increase a bit as you gain because your body is larger, which means you may need to eat slightly more to continue gaining.

How Many Calories to Gain a Pound

Researchers believe the 3,500-calorie rule may overestimate weight change, according to a 2014 article published in Today's Dietitian. A complex mathematical formula -- that takes into account how calorie needs change over time as your weight changes -- may be a more accurate way to estimate how many calories you need to gain or lose a pound.

According to the Pennington Biomedical Research Center's weight loss calculator, a 5-foot, 5-inch tall 50-year-old women who weighs 110 pounds can maintain her weight consuming 2,169 calories per day. She can gain 1 pound in a month by adding 105 calories a day, for a total of 2,274 daily calories. In a year, eating the same extra 105 calories, she will weigh 115.3 pounds -- a total gain of about 5 pounds -- which means her rate of weight gain slowed down, because it was less than a pound a month. To continue to gain 1 pound a month now that she weighs 115 pounds, her daily intake needs to increase to 2,302 calories, or a total of 133 extra calories.

A man at the same height and starting weight of 110 pounds needs 2,481 calories to maintain weight. Adding 80 calories, for a total of 2,561 daily calories, can help him gain 1 pound in a month, and in a year his weight will increase to 114.2 pounds.

Given this information, the number of calories you need to gain a pound depends on your gender, height and current weight.

Healthy Foods for Healthy Gains

Instead of setting a calorie goal for gaining a pound, you can simply focus on eating calorie-dense healthy foods. While soda, chips and other junk foods can give you extra calories to gain a pound, they don't offer much in terms of nutrition. Even when you're trying to gain weight, eat foods that offer other benefits, such as vitamins and minerals, to promote healthy weight gain. The same healthy foods recommended to someone trying to lose weight -- fruits, vegetables, healthy proteins and fats, and dairy foods -- will help you gain.

To put on pounds, concentrate on adding the higher-calorie options from these nutrient-rich food groups. For fruit, try 100 percent fruit juice, dried fruit such as raisins and dates, bananas, pineapple and avocados. Peas, sweet potatoes, white potatoes, corn, winter squash and lima beans all make healthy higher-calorie vegetable choices. High-calorie options from the grain group include dense whole-grain breads and bagels, grape nuts, granola, raisin bran and quinoa. Salmon, tuna packed in oil, beans, hummus, tofu, soy nuts, cheese, whole milk and full-fat yogurt add both calories and protein.

A cup of orange juice has 110 calories and meets more than 200 percent of the daily value for vitamin C. A 1/4 cup of raisins also has 110 calories and a little more than 1 gram of fiber. One medium sweet potato has 100 calories, 4 grams of fiber and meets more than 400 percent of the daily value for vitamin A.

Adding Calories With Boosters

Calorie boosters are foods that can help add a little extra to what you're already eating to up your intake without adding bulk, which may be beneficial if you fill up fast or have a small appetite. High-calorie boosters include oils, salad dressings, nuts, seeds, nut butters, dried milk powder, half and half, cheese, eggs, wheat germ and avocados.

One tablespoon of whole-fat dried milk powder has 40 calories and 2 grams of protein, which can be mixed in your cup of orange juice, glass of milk, container of yogurt or bowl of soup, to name a few. You can add 1/4 of an avocado to your sandwich or salad for an extra 80 calories and 3 grams of fiber. Mix 1/4 cup of chopped walnuts and 1/8 of an avocado with your medium baked sweet potato to make a 330 calorie potato. Saute veggies and grains in oil; mix eggs into casseroles and ground meat, and add cheese to your baked potato for extra calories.

The Importance of Strength Training

It may sound contradictory, but working out is an important part of your weight gain plan. If you don't exercise your muscles, 2/3 of every pound you gain will be fat, according to IDEA Health and Fitness Association. A good weight-gain muscle-building program should work out all your major muscles -- arms, shoulders, legs, chest, back, hips and abs -- twice a week with at least 48 hours in between each workout. To build muscle, exercises should be done to the point of muscle fatigue without losing form. To continue to make gains as you go, you'll need to add more weight as the exercises get easier. Consult a personal trainer for an exercise routine and proper form. And always talk to your doctor before starting any exercise program.

Feeding Your Muscles for Gains

To gain muscle, you'll need an adequate amount of protein on your weight-gain plan. When strength-training to build muscle, you require 0.7 to 0.8 grams of protein per pound of body weight daily, or 77 to 88 grams for a 110-pound person. Eat a variety of protein-rich foods -- meats, fish, poultry, eggs, beans, tofu, dairy or nuts -- to get all the amino acids your muscles need to grow.

Roasted white meat chicken helps build muscle, with 150 calories and 24 grams of protein per 3-ounce serving. A hard-boiled egg is convenient when you're on the run, and has 78 calories and 6 grams of protein per large egg. Non-meat eaters can get calories and protein from tofu, which has 78 calories and 10 grams of protein per 1/2 cup.

Eat a carb and protein snack within 30 minutes of finishing your strength-training workout. During this time period, your muscles are primed for building. The protein helps repair and grow your muscles, and the carbs help replenish your energy stores. Good post-workout snacks include a glass of chocolate milk, Greek yogurt and fruit, peanut butter and whole-grain crackers, or a turkey sandwich. Eat a regular meal three to four hours later.