Hi, Just thought I'd post quickly on here to say hello. I've been incredibly thin my whole life. I have a pretty fast metabolism and due to an illness as a child, I don't think my body processes fats very well. According to the fitbit aria I have a body fat percentage of 6% despite not being all that fit or healthy to start. I'm a typical programmer, frequently missing lunch, if I'm just trying to solve a tricky bug, and then suffering later (I can sometimes be literally shaking by the end of the day). Anyway, I've decided now in my thirties to finally take this seriously and try and gain some weight and put on some muscle mass. Ideally I want to get my fitness levels back up to be able to play a full game of basketball again. I'm making an effort to eat more than normal, mixing in porridge with my muesli and stocking up on fruit and nut bars, but I can't really take the Paleo diet too seriously, as I need whatever calories I can get. So to start will be just be trying to get through the beginners bodyweight routine, and also work towards being able to jog for an hour (on alternate days). Hope this makes sense, happy to take critical advice.