Regular meals
Regular meals are essential for pregnant women: eating regularly will allow you to digest your food better, absorb nutrients better, not tire out your digestive system, avoid bloating and heartburn. If you're suffering from stomach upsets or digestive problems, break your meals up: have 3 light meals a day and 2 snacks. Never miss meals, and eat at regular times as far as you can.
Different needs
For a healthy pregnancy and a healthy baby you need to gain weight regularly and gradually. Gradually increase your daily calories: during the first trimester, increase by 150 calories a day, and increase by another 350 calories during the second and third trimesters.