For my dd's carpool yesterday I brought black bean burritos. Sometimes a large salad and crackers or bowl of pasta. I have 3 tweens though that I drive and they are HUNGRY! For my 8 year old I will pack a boiled egg and fruit, or a bagel with cream cheese and fruit, or yogurt and carrots, usually 2 smallish things, not a full meal like I do for the older ones.
I admit to loading my little one with bad food - high fat high sugar, ceareal bars, tripple chocolate brownies, date cake,chocolate bars etc. But in my defence we do eat healthily 99% of the time ( I even make my own bread), all the cakes are home made, and she really does need the calories
Raw almonds. I toss in a few organic chocolate chips and she LOVES it. I also do up some healthy granola bars that are almost exactly like the top brand chewy chocolate chip ones but instead of processed sugars it uses raw honey and organic choc chips. Bananas are a good pre-workout snack. Two bananas will give about 90 minutes worth of good energy.