For those of you trying to put on weight, it would definitely be worthwhile chatting to a dietitian about how to do it propertly. It's not just a matter of eating more food or higher fat food.

Carrying abdominal fat around your middle can still increase your risk of heart disease, even if you're not overweight, so whilst your BMI has some value, your body composition (muscle:fat ratio) is also important IYKWIM.