instruction: hello I am writing an enquiry regarding my weight I am a 18year old female and I weigh 42 8kg and my height is 158 160cm I have been this weight since I was around 13 years old my weight has always been around 40kg I was wondering how I could gain weight in a healthy manner the main reason why I do not eat a lot is that I am not hungry so on some days I eat one meal in a full day however there are some days where I will eat meals including snacks however even on those days even if I feel as if I have had a lot of food my weight remains the same I am concerned as I have realised that I am well below my average age group in terms of weight and I am not sure what to do also I am not sure how much I should eat in a day because when I ask people around me I realise they eat less than me but maintain a healthy weight so I am really unsure how to approach my problem thank you