Have you ever had a great work out and got stuck talking to your friends after for way longer than you expected and then you had to stop and run three errands before you were able to get home and eat a "healthy meal?"
Your driving around and it is noon and you haven't eaten since 7:30am that morning and you are so hungry that you want to eat the scrap paper on the floor of your car. Very common. Always be prepared for when hunger strikes and you need food immediately. Carrying a bag of nuts or a yogurt can help with those unexpected hunger pains. Or just pack you're lunch every morning just in case something like that happens. It can save you a lot of calories and money!