Gaining weight through muscle

I'm about 5"3 and I weigh around 7 stone. I always wanted to put on a bit more weight, but no matter what I eat (I have the most unhealthy diet ever hehe), my weight rarely changes. It also doesn't help that I had the flu recently, which caused me to lose even more weight.

I do quite a lot of sports anyway, and I thought it might help if I gain weight through building up muscle instead. I'm a bit busy with homework etc, but I have a bit of free time in the evening. I've got free weights- dumbells and leg weights and an exercise ball if this helps.

Where would be the best area to target to gain this muscle? I was considering the arms, but I'm not sure if this would make a substantial difference, and it might be better to work on the quads, hamstrings etc.

Thank-you!

7 STONE!!!! how old are you? Im wondering becuse you seem very light and short!, in the nicest possible way.

Firstly, why anon post..
Anyways, regarding weight gain..depends on number of factors, genetics, diet training etc..The most important thing is to eat right..you would need to increase your calorie/carb intake by at least say 20%..try to eat clean, not too much junk..and eat more often
Training..your best bet is to go with compound exercises..so press ups, dips (probably one of the best exercises) squats..use bodyweight for all these exercises until you get stronger..then use weights (approx 3/4 weeks later) If you want any more detailed info PM me..or if you want a routine/tips or something

Ah, in the past some people have gone a bit funny when you ask for advice regarding weight gain- "Count yourself lucky you're not overweight" etc.

Thanks for all of the help!

if you want to become a weed, then ask 'p1mp' for advice. he's about as clued up as a box of rocks.

I'm almost fifteen- yep, I am rather short, no other way to phrase it