Great advice from above poster...I have nothing to add x
It is normal to lose your appetite at the start of pregnancy! Right now your baby is in early development and is not requiring much! As long as you are taking your prenatal vitamins you will be fine! Once your baby is developed more and becomes active your appetite will return! Once in the third trimester you will have to up the nutrition intake to give both you and baby the proper nutrition and energy!
I used to only eat about once a day too! I notice that once I entered into the third trimester my appetite kick into full swing! I found myself snacking all the time on fresh fruit!
If you find that once you get farther along and you do not have the urge to eat more contact your doctor! They may have you drink protien shakes or other nutrition drinks to off set the lack of extra nutrition!
Congrats and I Hope you have a smooth healthy pregnancy!