Q: i mant to increase my weight

A: Two words: EAT MORE! :) It really comes down to simply eating more -- even the skinniest guys can gain weight if they make up their mind to eat more every single day and every single meal. If you're still not gaining weight, then you simply have to eat even more!

If you specifically want to add this weight as all muscle, then it's a little more involved -- you still have to eat more, of course, but you need to make sure you gain weight slowly (about 1 pound every two weeks) or else you'll be gaining a lot of fat instead of muscle. And you also need to do heavy whole-body weight training. You can fill out my fitness guide specifying 'Gain Muscle' as your goal to get a suggested diet and exercise program. It'll also give you tips how you can customize the diet to your own tastes. Just remember that in any case the main thing will be to eat more food to slowly but surely gain weight.