During my first tri, i felt very very very tired. I just wanted to laze on the bed and do nothing. I didn't have good appetite and lost 4.5kg. My husband had to stop eating certain food because i can't stand the smell.
You can try munching on fruits or any food that has less intense flavours. Some of the food i can remember having were fruits, yogurt, milk, potato gratin, bread and eggs. I always kept in mind that i should at least eat something for the baby eventhough i don't have any appetite.
But don't worry too much mummy, once you hit second tri, your appetite and energy will be back!
(Oh on a side note, i always bring the essential oil inhaler with me everywhere i go since our sense of smell heighten. It's great when you are in crowded spaces.)