How can I gain weight?

The thing is that I'm really thin. I have been that my whole life because when I was 6 years old to age 11 I stopped eating because I was so picky when it came to food. It always took me 2hours to eat and I always sat alone because no one had the patience to sit and wait for me. :P

I refused to eat food that looked weird and smelled bad.

Now I'm older and realized how stupid I was. But I was so young and didn't know better. Now I have to live with one little mistake I did several years ago.

I have tried to eat more, but I can eat how much I want without gaining any damn weight. It's super annoying. I don't want to be thin. I just want to be normal like everyone else.

I'm 161cm, got no boobs (A cup -.-), my wrist is 14cm around and my waist is 67cm. Here's a picture I took few minutes ago: link

As you can see, really long and thin arms. I hate it. :/

I usually cover them when I go out. Also, no curves. -.-

In magazines, commercials on TV etc, you only see advice on how to LOSE weight. Never gain. I guess it's less common.

But can anyone help me, please? ;/

How can I gain weight?
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