Can you help and tell me why it is so and how I can solve this problem?

Yeah im pretty thin too... i havnt been able to gain weight no matter what i eat. Cept over the past couple months ive started running, gained 4kg... maybe exercise helps?

Hi,This is very interesting - as I used to have the exact same problem. Just to let you know I used to weigh 9 stone when I was 19 and now I way 13 stone - still with a low body fat index.The trick is to revolutionise the way you fuel your body. This will take time and will work in different ways, with different people. It is crucial that you are 100% committed to your cause to gain weight as well, due to the fact that if you are not in the correct frame of mind - you'll never succeed.You need to start eating for 2 people as well - this will be a struggle at first, but eventually your stomach will get bigger to accomodate all of this new food! You need to make sure you eat a healthy balanced weight gain diet. Lots of pasta, cottage cheese, eggs, meat (especially turkey and chicken breast) and other healthy "bulky foods". This is crucial as you need to be adding the correct calories to your diet to make it work. Your weight gain will not happen over night, these things take time - I suggest visiting some bodybuilding and men's fitness sites, and search for weight gain diets. Be careful though - use your common sense. It is important that you set yourself realistic goals as to how much you want to change. Work out - eat well - drink water - stay healthy and you should reach your natural optimum weight. As after all - we're all different and comparing Dannie De'Vito with Arnold Swarzenneger is not a good example!Good Luck !