I assume you’ve had a complete medical checkup? The shakiness and lightheadedness sound like hypoglycemia.

If you haven’t had that checkup, you should. If nothing shows, you might consult a nutritionist to learn how to gain healthy weight.

I would get to a nutritionist, they can give you the best advice. They will set up a meal plan for you, so that you have a good balanced diet. I would stay away from the junk food/sweets not because you are trying to loose weight, but just because they are really bad for you, and because you can eat a lot of them and not gain any weight, it means that you probably don’t think of all the times you eat them. You need to a good balanced diet, and enough protien/carbs and probably take supplements and more proiten in the morning. You also need to work out, to strengthen your bones, women like you with small bones are at great risk for osteoporsis. Drink enough milk/eat youngrt and eat of lot of leafy green veggies. Don’t eat junk food/sweets to gain weight, use healthier approaches.

could you pass some of that genes/metabolism to me =(

You absolutely DO NOT want to try to slow-down your metabolism! That will be catastrophic to your health and the long-term affects will be debilitating!

That being said. Junk food NEVER helps add lean mass, just fat. Once you create new adipocytes (fat cells) to store this fat in, they can NEVER be lost (without dangerous surgery).

People who claim that they eat a lot, rarely eat as much as they think they do. Start a food log, writing down everything you put in your mouth, approximate portions, times of intake, etc. Keep it for a few weeks, then assess your average caloric intake. Without accurate data, you can’t say how much you’re taking in, or how much you’re increasing your intake.

To get enough calories to gain from healthy, clean food, you have to eat A LOT! 6-9 times a day, no more than 2-3 hours apart, train regularly with weights, and get adequate rest and water. It’s a long, slow road, expect 1-2 pounds a month, 10-15 pounds a year, consistently. That’s the only way a natural lifter can do it.

it’s exactly the same as me! i bet so many people are jealous of u…i’ve accepted it, cos there’s nothing u can do to slow it down. try gaining some muscles, i’m really into sport and by doing exercise, toning your body and getting extra muscles (not too big) actually helps u put on weight…take advantage of eat and be proud!!! u can eat anything, anytime, anywhere and as much as u want without worrying about gaining extra weight! Hav fun and enjoy life!!!