how to keep this weight off ?

You can lose 10 lbs/mo with this low-carb food/exercise plan:

Breakfast: Cook oatmeal or health food store cereal in water with wheat bran. Make a pot of it on weekends and nuke 1/2 cup each morning. Then stir in low fat milk or yogurt, banana, walnuts and berries. Drink hot Ovaltine. Breakfast should be your largest meal of the day to raise blood sugar level which falls during the night.

Lunch: Egg, tuna or turkey ½ sandwich on multi-grain (not just whole wheat) bread with bean or alfalfa sprouts, yogurt, fresh fruit. If you had meat loaf for dinner, bring a meat loaf sandwich on whole grain bread (NO mayo). On cold days, a squatty thermos of hot chili, split peas with ham, or beef stew.

Snacks: Fresh (not canned) fruit. Nothing ever from a vending machine. Fruit smoothies (frozen thawed fruit, yogurt, banana)

Dinner: salad with white meat chicken and fresh (not canned) veggies: tomatoes, 2 kinds of lettuce, 2 kinds of shredded cabbage, shredded or sliced carrots, alfalfa or bean sprouts, zucchini, green or red peppers, hard boiled eggs, brussels sprouts, broccoli, cauliflower, tofu, cottage cheese, spinach...Instead of dressing, squeeze 1/4 tomato over it.

Or homemade bean/vegetable soups; great way to recycle leftovers.

Or grilled fish with steamed veggies.

Or omelet: In blender, whip together eggs, tofu, cottage cheese, onions, garlic powder. Cook with mushrooms, chopped tomatoes and green or red peppers.

Avoid junk food, fast foods, anything from a vending machine, gluten, pastries, desserts, syrup (even canned fruit in syrup), peanut butter, fat/grease (pork, wieners, chops, bacon, salami, pizza, chips, fries), pasta, potatoes, ramen, popcorn, white bread, rice, canned veggies, ice cream (it’s lard + chemicals), chips, tobacco, alcohol (damages brain).coffee (carcinogenic). no oil except olive and mac nut. Sodas (loaded with toxins; leads to stroke, obesity, kidney damage, high BP), anything with sugar (cancer cells feed on sugar, it wreaks havoc on your liver, mucks up metabolism, impairs brain function, makes you more susceptible to heart disease and diabetes),

To keep your skin clear, drink water, tea, veggie juice, unsweetened fruit juice.

Join a gym; they have all the equipment and staff to show you how to use it to get the look you want to achieve, but you have to ask them. Much cheaper than buying your own equipment. Go hiking, biking, jogging, bowling, swimming, rowing, jump rope, play tennis, badminton, volleyball, soccer, jumping jacks, lift weights, trampoline? To tone your tummy, do sit ups, push ups, pull ups, leg lifts, butt raises and crunches.

For more energy, take Super B complex.

And keey that retainer for ever. Wear it every night because teen tend to move, even after braces.