Thirteen-year old teens often suffer from body image related issues. Smaller teenagers feel different from their peers and might wish to gain weight. This issue affects both boys and girls as they work through puberty. While the desire to gain weight might be intense, it should only be done following a doctor's suggestion and with parental supervision. Doctors will evaluate a teen's height and weight to determine if he is actually underweight. In medical terms, "underweight" means that the teen falls into the 5th percentile or less on the BMI-for-age scale. Once a doctor determines that a teen needs to gain weight, the emphasis should always be on making healthy food choices and exercising properly. These are lifestyle aspects that parents can control.
Although it may seem counterintuitive, reduce your teen's portion sizes. If a teen feels pressured to eat more and feels sensitive about her weight, eating becomes a chore and each meal becomes a source of stress. Instead, give your teen smaller, more manageable portions and allow second helpings.
Increase the Number of Meals and Snacks
According to nutritionists at the Mayo Clinic, underweight teens should eat five or six small meals per day. This would include the traditional breakfast, lunch and dinner, plus large snacks between each of these.
Choose High-Calorie, Nutritious Foods
Provide your teen with high-calorie, nutritious snacks. Good choices include nuts, cheese, yogurt, dried fruits, granola and sandwiches made with whole-grain breads.
Substitutions and Additions
To help your 13-year-old gain weight, you can substitute high calorie food for lower calorie foods. For example, use whole milk instead of skim milk, serve smoothies instead of plain fruit juice, or choose bananas over grapes. You can also increase the caloric content of your teen's meals by adding small amounts of calorie-rich foods. For example, you can add a dollop of peanut butter to your teen's apple slices, an extra slice of cheese on his sandwich and fruit to her cereal. You can also add finely ground flaxseed to smoothies and cereals.
Be sure that your 13-year-old remains adequately hydrated, but do not serve drinks with the meal. Beverages will fill your teen up fast, leaving less room for food. Instead, encourage your teen to drink before or after meals. Serve your teen juice or milk.
Good exercise habits can help your teenager gain weight. Strength training will build muscle mass. Exercise, in general, will also increase your teenager's appetite. Doctors recommend that teenagers get at least one hour of physical activity daily.