Healthy as a horse?

So I have this habbit of eating junk food too much but I dont gain anything. My parents say I should eat more healthy things but Im healthy as a horse. What should I do??

P.S. Im skinny as a stick

Drop the junk and eat Healthy, even snacks:

Here are 22 portable and healthy snacks that make the list of dietitian's favorites:

Half a peanut butter sandwich on whole-wheat bread
Low-sugar, whole-grain granola bars that have at least 3 grams of fiber
Whole-grain crackers or whole-wheat tortilla with hummus or nut butter
A handful of unsalted or lightly salted dry-roasted nuts
Individual unsweetened applesauce with a few dry-roasted walnuts
Small apple with 2 teaspoons peanut butter or 1 ounce low-fat cheese
Ants on a log -- celery with nut butter, topped with raisins or other dried fruit
Half of a single-serving string cheese with a small piece of fruit or a few whole-grain crackers
4-ounces to 6-ounces of low-fat yogurt or yogurt treat
High-fiber dry cereal with a few nuts or seeds and dried fruit (put this in a baggie for a make-your-own snack pack)
Individual packs of carrots, celery sticks, or apple slices, with a protein source like a tablespoon of nuts, nut butter, or low-fat cheese
Pretzels and low-fat cheese
Whole-wheat cracker sandwiches made with natural nut butters
1 ounce of lean meat and a few whole-grain crackers
3 ounces low-fat or fat-free cottage cheese and a few whole-grain crackers
1 whole graham cracker and 1 teaspoon nut butter
Raw vegetables with 1/4 cup low-fat ranch dressing
100-calorie pack of low-fat popcorn rich in whole grains and fiber
Handful of tortilla chips and salsa
100-calorie ice cream treats
Skinny latte (made with low-fat or skim milk)
Small bowl of whole-grain cereal with skim milk or low-fat yogurt

Take care !!

wow thx that was really helpful