Spend a day this week fasting. If you're body is not used to being neglected of food, then choose a day when you are a little less active. When you start bringing fasting into your life, it needs to happen in small steps. You could start by fasting just one meal, if you feel able fast for a whole day.
In this time you fast, during your meal time where normally you would eat, spend time declaring to God that He is your daily bread. Before you finish your fast, you could bring in prayer those on your heart.