How tall are you MM? I was 55 kg and about 6 foot. Now Im 66 kg and about 6"1'. The extra 1 inch of growth has kind of negated the weight I gained, but oh well. I still need to gain an extra 10 kg to have some semblance of health about me. But I have a high metabolism and it's kinda hard to gain weight, especially with uni travel times (Fucking UNSW. FUCKING DIE)-- err, but yeah, eat something every 1.5 hours. Have an egg everyday. Exercise. It increases your appetite. Try tuna. Fast food doesn't work. If you have a high metabolism, fast food goes straight through you and doesn't get absorbed. It's shit. Eat something that's dense in calories. There's also the Gym + Protein option, which is pretty popular, but personally I can't be fucked. I'm sure there's some other BoSers who can offer advice relevant to this path.