If you aren't hungry- you probably aren't denying yourself or the baby anything. You are only supposed to 'eat for two' in the last trimester but it only really means the same calories as a bowl of cereal.
I was always hungry with my first and put on 21/2 stone- one of which I've never been able to shift. But I was much more active- working a hard job and early hours so thats prob why I was so hungry.
I thnk the main thing is to lilsten to your body. You obviously know you are eating the right things - presumably a healthy balanced diet and not still restricting yourself as on some diets, and you know what kind of snacks you should be having. Obviously, if you begin to feel light headed or tired then you could increase snacks in between meals etc.
Some people are so sicj in the first trimester they are barely eating as they can;t keep a thng down and I'm certain that has no adverse effects.
You should be able to call up your midwife when necessary if you did need some reassurance, rather than wait til your next appointment.
I would also suggest maybe buying some of these pregnancy mags as they quite often discuss food and give recipe ideas and also a look at what is a balanced diet throughout the day although I couldn't eat that much stuff! They seem to have two main meals, a large breakie, 3 snacks throughout the day. I'd feel lke a cow- constantly grazing!!
Anyway, good luck with the rest of your pregnancy
mum to 3 yr old and 23wk bump