What is the first step for someone who is having difficulty trying to gain weight?

Believe it or not, weight gain is just as hard for some people as weight loss is for others, especially men, notes Marjorie Nolan, MS, RD, a spokeswoman for the American Dietetic Association. “Depending on how underweight you are, it could be just as unhealthy as being overweight,” she says. A poor diet can lead to health complications, whether you’re thin or fat.

If you need to gain healthy weight, overeating, especially empty-calorie foods, isn’t the answer. “You want to eat right so that you’re gaining muscle and not fat,” Nolan explains.

Follow these 10 steps to smartly gain muscle — and weight:

1. Eat frequently. One of the first steps toward healthy weight gain is eating every three hours. “If you go for too long without eating, you metabolically start to slow down, which is unhealthy as well,” Nolan says. “When you eat every couple of hours, you’ll eat more calories and prevent your body from losing lean body mass.”

2. Go for variety. Eat at least three different foods at every meal and snack. “At meals, that’s easy,” comments Nolan. “You probably eat a protein, a starch, and a fruit or vegetable.” But you want to be sure to include at least three different foods when you’re eating snacks as well. “That way you’re getting different nutrients to build muscle with.” Good snacks for weight gain, for instance, might be yogurt with fruit and peanut butter with crackers. “Trail mix is also an excellent snack choice because it has everything in it,” adds Nolan.

3. Choose higher calorie foods. “When we think high-calorie foods, we think fat,” Nolan explains. Fat typically has more than twice as many calories as the same amount of protein or carbohydrates. But stick to the unsaturated, heart-healthy fats found mainly in vegetable oils, nuts, seeds, olives, and avocados. Avoid coconut and palm oil because they contain saturated fats. Good choices for calorie-rich weight-gain foods include nuts, seeds, and nut butters such as peanut butter and almond butter.

4. Drink lots of fluids. Drinking 100 percent fruit juices and smoothies can provide calories along with vitamins and minerals, advises Nolan. Make a smoothie with 1 percent to 2 percent milk or low-fat yogurt, strawberries or bananas, and peanut butter. “You can add a tablespoon or two of protein powder or plain whey powder to bump up the calories and protein content.” Even if you are trying to gain weight, Nolan warns, “be cautious when using just protein powders to make shakes or smoothies because they can be jam-packed with artificial stuff.”

5. Eat at bedtime. Have a healthy snack or late dinner. “At nighttime our bodies are really active. Our cells are regenerating and repairing and healing. By eating later or having a snack before bedtime, you’re allowing your body to draw from your day’s worth of calories,” says Nolan.

6. Get enough sleep. “Your body has to have time to rebuild muscle and store it in a healthy way versus just turning food into fat,” Nolan says.

7. Be active. Resistance training is how to gain muscle — it builds muscle tissue that helps ensure healthy weight gain, Nolan explains. You should do resistance training at least two to three days a week. Be certain to do at least one to two strength training exercises per muscle group. “Don’t neglect cardiovascular exercise like jogging, bicycling, or swimming because the heart is a muscle that needs to be worked out, too,” adds Nolan. “If you gain weight, you’ll have more muscle to which your heart needs to circulate oxygen and nutrients.”

8. Go protein-crazy. You should eat 1.5 grams of protein per kilogram of body weight, which is equal to about 94 grams for a 125-pound person. Make sure to have some form of protein at every meal. Healthy, protein-rich foods that will help you gain weight include low-fat dairy, lean meats, and nuts or seeds. “Protein is most easily converted into lean muscle mass,” Nolan says. It is essential to gain muscle mass.

9. Say yes to carbs. Carbohydrates are another food group that can help with weight gain. “If you want to build muscle mass, you need to eat enough starch or carbs to use the extra protein,” Nolan says. “Starches or carbohydrates are stored in the muscles and they provide the energy you need to create body tissue. If you want to build muscle, you need enough carbs to fuel the process.” Good carbs include multigrain, rye, or pumpernickel breads, beans, lentils, couscous, brown rice, and sweet potatoes.

10. Keep a food diary. This strategy can really help when you’re trying to gain weight. “People who need to gain weight often don’t realize how many calories they’re eating,” notes Nolan. Keep track of what and how frequent you drink and eat. If you haven’t gained weight, you can use your food log to figure out where to fit in more foods or fluids.

Gaining weight can be a challenge. If you focus on building lean muscle mass instead of fat, though, you can gain weight in a healthy way.

What is the first step in trying to gain weight?

What are three strategies that can help a person gain weight?

Why is it difficult for some people to gain weight?

Which approach is recommended for underweight people gaining weight?