A boy's body undergoes enormous changes during his teen years, many of which can start as early as age 14. Boys start to gain weight, particularly muscle mass, and experience a broadening of the shoulders, deepening of the voice and development of facial hair. Others don't hit this stage until they're several years older, and they may feel left out socially when their friends develop earlier. If your doctor encourages you to gain weight because your thinness is endangering your health and energy, then eating a balanced diet, with extra high-calorie and nutritious snacks, as well as quality exercise will help you. Be patient with your body, though, and try not to rush the process; it can take three to four years to reach your adult size.
Underweight Teenage Boys
You may not fully reach your adult weight til well after age 18, so take steps that gradually help you gain weight. Adding too much weight too soon increases your body fat, rather than helping you develop healthy lean muscle. But if being skinny depletes you of energy, makes you feel self-conscious or negatively affects your immune system and health, adding calories and appropriate resistance training will help you become your healthiest.
Make sure you're eating enough calories to support your current weight. Talk to your doctor about your activity level, and she can help determine that calorie number. Then, add 250 to 500 calories to the maintenance number to gain a healthy 1/2 to 1 pound per week.
How to Eat to Gain Weight
Adding calories from healthy foods and not from junk-y snacks or fast food, helps you put on quality muscle mass. Processed foods, such as soda, chips and white bread, have extra calories but offer little nutrition. These foods don't help you look or feel better. A diet that's nutritionally poor causes you to miss nutrients that support optimal growth.
Increased serving sizes of homemade meals, such as extra servings of protein, unprocessed grains and starchy vegetables, help increase your daily calorie intake by 250 to 500 calories per day. For example, serve yourself two grilled chicken breasts and instead of one fist-full of brown rice, have two, or choose the largest baked potato offered. When you have a choice, opt for the higher calorie -- but still healthy -- versions of foods. Choose chili over chicken noodle soup, make sandwiches on dense, whole-grain bread instead of white bread and have broccoli with melted cheese rather than an iceberg lettuce salad.
If you don't increase your meal sizes, then increase the calorie density of your meals -- meaning you should make high-calorie additions to the foods you do eat. Cook oatmeal in milk, and stir in raisins and walnuts; spread avocado on sandwiches; and add olive oil to salad or use olive oil as a dip for bread.
Easy Weight Gain Snacks for a 14-Year-Old
Eating mini-meals between breakfast, lunch and dinner helps add calories. When you're at school, pack nuts or trail mix in your backpack for you to grab between classes. Stash a peanut butter sandwich on whole-wheat bread in your after-school activity bag to fuel sports, band or choir practice. A snack before bed, such as whole-grain cereal with milk, also boosts calories.
Dried fruit, yogurt, smoothies made with pureed fruit and milk, and even deli meat and cheese, are other portable snack options you can easily carry with you so you don't miss meals or snacks. Drink milk or fruit juice between meals to boost your calorie intake. Drinking a lot of liquid with meals can squelch your appetite, though. Unless directed by your doctor, skip supplements designed for weight gain. Whole foods offer more nutrients and fewer preservatives to support good health and growth.
Physical Activity Supports Weight Gain
Most teen boys need at least an hour of physical activity per day. This can be sports practice or simply messing around with your friends, with a soccer ball, for example. Resistance training at the gym helps you develop muscle mass and promotes healthy bones, but it won't necessarily cause you to gain tremendous amounts of weight. If you haven't yet reached puberty, developing large muscles isn't possible. Also, your build may not be designed to bulk up, even after you reach puberty. If you're naturally lean and lanky, resistance training can make you stronger and healthier, but you may stay thin. Talk to a coach or an adult with knowledge of lifting weights to guide you on proper form, technique and weight choice.
Adequate physical activity helps you sleep well at night, which is essential to proper growth. Get 8 to 10 hours per night to give your brain and bones time to develop, and to allow your growth hormone to release.