I know what you mean it's not very nice when taking your top off in summer and your friends calling you names like 'tin ribs' 'pokey' and 'matchstick legs'
My mates called me some funny stuff lol, I am still skinny but I am putting the effort in to gain weight.
I was pretty skinny about 3 months ago at 128 lbs, 5'10 age 17.
3 months on I have gained 12lbs and am now 140lbs.
Not a lot but hopefully by the end of this year I will hoped to have put on a considerable amount of weight.
What have I done?
-I have been eating 6-7 meals a day. - At first it sounded very daunting having to eat this many meals a day but in time your body will get used to it and it will be normal to have that many meals a day.
-They have to be healthy foods, not 7 mcdonalds's or 7 portions of greasy chips. A good intake of protein, carbs and fats should do the trick.
-For maintenance I need to eat 2500 calories a day. I eat 3000+ calories a day in order to gain weight.
-Start lifting weights in the gym, heavy ones. Along with a good diet this will stimulate growth.
These are just skeletoral tips (no pun intended) on how to put on mass.
Read around the forum I am sure there are 10000s of people cleverer than me