Monta
Do not obsess about your weight.
Do not throw yourself into an exercise routine that wears you out, and wears you down.
Do not go on occasional fasts.
You want the quick fix?  Get taller.
Another quick fix is to get deathly ill.
I'm not joking here.  Quick fixes are murder for people who have weight problems.
You'll gain the weight back... plus 10.
I've struggled with my weight my whole life.
During High School I used to go on 3 day fasts every month.  For a while there I was taking diet pills.  And I was always on some kind of diet.  Name it... I tried it.  My friends, my family, and I had all managed to convince me that I was grossly overweight.  
As I look back on it now... I wasn't life threateningly overweight.  But I had this mental image of myself as a blimp.  
I lost lots of weight, but it always came back.  Plus a bit more.  So I lost it again... and it all came back.  Plus.  So I lost it again...
Once I started college I became fanatical about running.  I kept running, kept dieting, worked construction... and boy did I lose weight.
I was down to 175 pounds, and on me that left me with my ribs sticking out, and you could count the vertebrae on my spine even while I was wearing a T-Shirt.   But I was still convinced that I had to take off at least 5 or 10 more pounds.
The weight stayed off during the 8 or so years that I kept running, 7 days a week, 7 to 10 miles per day.
Then my knees gave out from the running.  I developed some lower back problems... I had to stop running and before I knew it... the weight came back.
The weight came back... but my knees didn't.  
Obsessing about your weight now will put you on the yo-yo weight loss weight gain program for the rest of your life.
I'm not saying give up... eat whatever you like and never exercise.
I'm saying, don't obsess.  Don't become a fanatic.  Don't look for the quick fix.   don't let yourself think that life will be great if only you can lose that 10--20--50 pounds.  
Find something you can do... something you can stick to... that won't make you feel like you 
HAVE to do it.
Me?  I can't run anymore.  If I try, I wake up the next morning with my knees swollen up to the size of watermelons and they hurt like a pistol.
But I walk my dogs every night for an hour before going to bed.  Doesn't hurt my knees, and it's no great sacrifice.  No special clothes, no joining a gym, no big deal.  The only thing is... I never skip a night.  It's not a chore.  It's just part of my life.  Something I do every day.  And it helps keep my weight down a bit.
As for food... I don't diet anymore.  I do what I can to refrain from pigging out.  But I don't diet.
_________________
Manga is to Literature
what Graffiti is to Art