Briefly, a third of most meals should be starch-based foods (such as bread, cereals, potatoes, rice, and pasta), with fruit and vegetables.

http://www.patient.co.uk/health/planning-to-become-pregnant

Food and diet

Eat a healthy balanced diet

Aim to eat a healthy diet (which everyone should be eating, not just pregnant women). Briefly, a third of most meals should be starch-based foods (such as bread, cereals, potatoes, rice, and pasta), with fruit and vegetables.