Dear Sir or Madam,
I am a 25 year old woman that has always been underweight and has struggled (and still does) to gain weight. I currently weigh 55kg, which is the highest weight I have ever been. Since I do look very skinny, having nearly no chest and a very scrawny upper body (waist about 64 cm), people accuse me of having an eating disorder, which is an illness to be taken seriously, however I luckily don't suffer from. I have never been on a diet to loose weight, rather the opposite. I always try to eat as much as I can to gain weight. 5 years ago I started to work out once, sometimes twice a week, mostly weight training and only very little cardio, in order to gain muscle mass.
My sister currently weighs about 53 kg after having a baby boy and has always weighed less than me, but looked more curvier and healthier. When she got pregnant, her starting weight was 50kg. She does not eat well, only little portions and only twice a day (an estimated calorie intake of 1500). If I ate as little as her, I would probably drop down to 45 kg in the blink of an eye. I do eat 3 times a day, mostly double the amount, sometimes even triple, and also snack, but to no effect... And still feel hungry after 2 hours.
Why is that? And what can I do to make myself look a little more like the 25 year old woman that I am? Thank you very much for dealing with my question!