Some teens, especially those who have already hit puberty, may be insecure or woeful of their thin bodies. Being underweight can be a serious problem for a teen and could cause fewer or irregular periods as well as loss of bone mass.
Whole-Fat Dairy Products
Never underestimate dairy products. Cheese is known to be a waistline-busting byproduct. Good, full-fat cheeses, butter spreads and yogurts may be what's missing from an underweight young person's diet. Take special care to offer different types of cheeses and dairy products to suit the picky tastes of your teenager. It may also help to add more cheese to dinner and lunch meal recipes. Whole-fat dairy can quickly aid in weight gain for a teen who normally doesn't indulge in much dairy.
Physical Exercise and Breakfast
If your teen is active, find ways to slow down their vigorous burning of calories by reducing the intensity of workouts. If they play a sport, suggest frequent meals that will compensate for what was burned off. Also, incorporating larger portions during regular meals and more rest days might help the teen put on weight faster. Some teens tend to skip breakfast; just adding breakfast can speed up weight gain.
Nuts and Oil
Avocado, olive and canola oil are all tasty and healthy oils to cook with. Avocado oil is a great addition to balsamic vinegar for a calorie-rich vinaigrette. There should be two parts avocado oil to one part balsamic vinegar. Nuts are also a good choice; cashews, peanuts and pine nuts are protein-rich and can give you energy. Try incorporating trail mix into the teen's diet. Offer it as a snack with lunch or during breakfast.