How to get skinny, as a 15-year-old
So your build is pretty similar to mine (height/weight/age), so I will give you the same advice that I use.
Don't count calories
Unless you are constantly overeating (with your weight you aren't), you shouldn't count calories at you age. You're growing and need the extra energy.
Get a gym membership and a private trainer
If its in your budget, a gym membership and a private trainer would be a good combination. The trainer will show you the exercises and the proper form (bad form will lead to problems). If it isn't in your budget, then you will have to try and keep form yourself and do a lot of research on the internet, but this isn't preferable.
Cut junk food
Limit the amount of chips and chocolate that you eat. Now, I'm not saying that you're never allowed to eat junk food, but limit it to once or twice a week.
Limit fast food to maybe 2x per month.
Eat more vegetables and fruits
This is pretty self explanatory.
Don't focus on losing weight, focus on building muscle.
Muscle weighs more than fat. You could be getting skinnier and heavier at the same time. You shouldn't just weigh yourself, you should measure yourself around the waist and stomach.
The process also takes a really long time, so don't expect to be Channing Tatum by July.
Exercise over diet
I said this, you don't want to lose weight, you want to build muscle, so you should exercise.
Before I get to my routine, you have to remember
- If you're sore, don't work out
- Warmup and cooldowns are important
- I'm not your doctor/personal trainer. They know better
- Form is more important than weight.
- Start small
If you do decide to get a gym membership, buying equipment for home would not be the best idea. And vice versa.
Without further ado, my gym routine, using machines.
- 3x12 leg press
- 3x12 leg extensions
- 3x12 leg contractions
- 3x12 hamstring extensions
Upper body (everything is 3 sets of 12)
- Chest press
- Shoulder press
- Lat pulldown
- Pectoral contractions (I think that's what they're called)
- Leg raises in the Captains Chair
- 3x5 pullups/assisted pullups
- Bicep curls
- 3x1 minute plank
Mix in Cardio exercise on your off days. This could include sports (soccer, basketball), biking, walking, running, sprints, etc.
Eventually, over the course of the year, you will become more fit, raise your limits, and look and feel better. It will be hard work, results will come slowly. You have to stick to the routine and not quit. Good luck to you.