"No matter what I eat, I can't seem to gain weight..."

"What about those weight gain powders ... do they work?"

"How much more protein should I eat to help me bulk up?" 

Although two-thirds of Americans are overweight or obese, a handful of skinny people - including many athletes - feel very frustrated by their seeming inability to gain weight. Their struggle to bulk up is on par with that of over-fat folks who work hard to lose weight. Add in rigorous training for a marathon, soccer team, or other sport, and scrawny athletes can feel at a disadvantage, fearing that no matter how much they eat, they'll get even skinnier.

Clearly, genetics plays a powerful role in why some athletes have so much trouble not only gaining weight, but also maintaining any weight they manage to add. "Hard gainers" tend to be fidgety. They rarely sit, to say nothing of sit still. They are constantly puttering around, or when sitting, they are tapping their fingers, swinging their legs, twirling their hair, and shifting around in the chair. All of these activities burn calories that commonly end up in the midriff of calmer people who can sit motionless for hours.

If your son or daughter has a hard time gaining weight, they might have been told that consuming an extra 500 to 1,000 calories per day will lead to gaining 1 to 2 pounds per week. Unfortunately, nature often confounds this mathematical approach. For example, in a weight gain study where the subjects were overfed by 1,000 calories per day for 100 days, some subjects gained only 9 pounds, whereas others gained 29 pounds. (1)

How could that be? The answer likely relates to Non-Exercise Activity Thermogenesis (N.E.A.T.), the technical term for spontaneous movements that naturally occur in fidgety people. When you overfeed a fidgety person, they can become even more active, as if Nature wants them to burn off those calories.

Seven Tips to Gain Weight Healthfully

Fret not. Even very lean people can gain some weight when they systematically enhance their diet. Although they cannot change their genetics and their tendency to fidget, they can boost their calorie intake. If your child is a scrawny athlete, is a teenage eating-machine who wants to weigh more, or are trying to bulk up for football, here are some tips to help them gain weight healthfully.

1. Eat consistently. Do NOT skip meals; doing so means they'll miss out on important calories needed to reach their goal. Every day, enjoy a breakfast, an early lunch, a later lunch, dinner, and a bedtime meal.  This might mean breakfast at 7:00, lunch at 11:00, second lunch at 3:00, dinner at 7:00, and a protein-rich bedtime snack at 10:00.
2. Eat larger than normal portions. Instead of having one sandwich for lunch, have two. Enjoy a taller glass of milk, bigger bowl of cereal, and larger piece of fruit.
3. Select higher calorie foods. Read food labels to discover which wholesome foods offer more calories. For example, cranapple juice has more calories than orange juice (170 vs. 110 calories per 8 ounces); granola has more calories than Cheerios (500 vs. 100 calories per cup); corn more calories than green beans (140 vs. 40 calories per cup).
4. Drink lots of 100% fruit juice and low-fat (chocolate) milk. Instead of quenching thirst with water, choose calorie-containing fluids. By having milk with each meal, an athlete can easily add 300 to 600 wholesome calories a day. One high school soccer player gained 13 pounds over the summer by simply quenching his thirst with six glasses of cranapple juice instead of water (1,000 vs. 0 calories). He consumed the fluid he needed (juice is 98% water) and the bonus was more carbohydrates to refuel his depleted muscles, plus a good dose of vitamin C to enhance healing. 
5. Enjoy peanut butter, nuts, avocado, and olive oil. These foods are high in (health-promoting) fats. They're a positive addition to a sports diet; they also help knock down inflammation. Their high fat content means they're calorie-dense. To boost good fats, add almonds to cereal & salads, spread extra peanut butter on the PB&J sandwich, dive into the guacamole with baked chips, and add extra olive oil dressing to salads. That's an easy extra 500+ calories/day.
6. Do strengthening exercise as well as some cardio. Weight lifting and push-ups stimulate muscle growth so that an athlete bulk-ups instead of fattening up. Plus, exercise stimulates the appetite and, sooner or later, you'll want to eat more. Exercise also increases thirst, so you will want to drink extra juices and caloric fluids.  Take note: Your athlete will not build bigger muscles by eating extra protein. While they will want to target a protein-rich food with 20-30 grams protein at each meal (and 10-15/snack), having more will not build bigger muscles. Resistance exercise builds muscles. To have the energy to do the muscle-building training, they need extra carbs. That's where drinking more 100% fruit juice and chocolate milk offer benefits; they'll be better-fueled & better able to lift heavier weights.
7. Don't bother to buy expensive weight gain drinks. A hefty PB&J with a tall glass of chocolate milk adds about 1,000 calories for about $2.00. You would spend at least $10 get-ting those calories from Muscle Milk.

By following these tips, your athlete should see progress, but honor their genetics. Most people do gain weight with age as they become less active, more mellow, and have more time to eat. Granted, that information doesn't help them today, but it offers optimism (or a warning) for their future physique!

Nancy Clark, MS, RD, CSSD (Board Certified Specialist in Sports Dietetics) is a longtime MomsTEAM/SmartTeams expert and counsels both casual and competitive athletes at her office in Newton, MA (617-795-1875). Her best selling Sports Nutrition Guidebook and food guides for marathoners, cyclists and soccer players offer additional information. They are available at www.NancyClarkRD.com. For her popular online workshop, see www.NutritionSportsExerciseCEUs.com.

References:

1. Bouchard, C. 1990. Heredity and the path to overweight and obesity. Med Sci Sports Exerc 23(3):285-291.