How can I GAIN weight?

Do the all American way:

BEER and BBQ and don't forget popcorn and TV

After making sure that you are physically in good health, and that there is nothing endangering your health, I have one word for you:

Arby's!

I got the same problem I'm 6f4 and 165 lost gain lost gain stress make you loose weight so smoke pot and have the munch and eat like a pig like I do =)

The first thing you should do is visit a doctor to make sure that there isn't a medical reason for your weight loss. While there ask, They are sure to have some Ideas about how to safely gain some of the weight back. I would recommend 3 good meals a day and perhaps a strength training program to build some muscles. The point is to safely gain the weight and keep it.

They say that the first bossy part to fluctuate when a woman gains or loses weight is her chest, so I'd expect that to come around if you gain some weight.

As for how to gain weight, it's pretty important that you talk to your doctor and make sure that you're doing it in a healthy way. Try to increase your calorie intake slightly (but not with junk food! ) and add in protein in healthy amounts. Other factors which may be playing a part are stress and under sleeping. Make sure that you are getting enough sleep and trying to avoid anxiousness, as this can occasionally lead to weight loss (and/or gain, ironically).

Ultimately, I'd suggest you speak with your doctor/nutritionist.

Hey! There is nothing too bad with being underweight! I'm just under 100 lbs and I look AMAZING! I don't understand why your boobs lost weight though. That's confusing. I've always had a bra size 32 D no matter what I weigh. And my boobs aren't even fake! If I were you I would embrace your body because being thin is IN! I mean come on, you've got the body of a supermodel, learn to LOVE it!
But if you're serious about gaining weight, don't over eat or eat junk food, hit the gym instead. Start weight training. You will gain serious weight FAST if you lift weights. Plus you'll get toned and lean in the process. Good luck! And remember LIFT WEIGHTS! No cardio, just pump that iron because we all know that muscle weighs more than fat! And as far as your boobs go as long as your weight training your upper body they'll plump up.

Also it depends on age. I was size A in high school. Now I am size See. I didn't have any children. I snowboard a lot thus losing lot of weight during winter, I get down to 103 lbs, but my chest remains the same and continue to grow. Could be genetic

I would recommend, eating a couple of cookies before going to sleep because your body shut down during night, thus allowing you to gain weight. But I would recommend toning as you try to gain so that way you don't get all flabby.

You do have a prob many people dream of but with that said. I think doing weight training with protein drinks will help you bulk up. Try healthy weight gaining foods like bananas, nuts, avocado. When doing weight training start off with small weights but try to build up to heavier weights since that will help muscles tone up and become bigger. As for chest size there a gym exercises for that as well.