What to Drink
Alcohol is often a big part of attending a race. Although it is not necessary to enjoy the experience, many do want to drink since it is a day before a holiday. Beer is by far the most popular drink at any race; keep it light. Drinking liquor can keep the calories low, but be careful what you mix with it. Water, club soda, diet tonic water, and diet sodas have no calories, but beware of the damage to your health diet sodas have been known to cause, such as heart attack or kidney problems.
Whether you mix it with your alcohol or not, it's a must to drink water when at the track. Water is always important, but with the sun reflecting off the track, it is easy to get hot and dehydrated more quickly than normal. It is worth it to carry in a gallon of water with you; a 32oz Nalgene bottle just isn't enough.
What to Eat
Avoiding deep-fried anything at the food stands is an obvious tip, but avoiding the food stands entirely is an even better choice. Part of the experience is packing your own snacks and carrying in your coolers and backpacks. I generally see a lot of grills, burgers, and brats at the track. Rather than brats and buns, last year we packed thin steak, tortillas, cilantro, onion, and lime to create simple and scrumptious tacos. In the past, we have packed fruit, veggies, and nuts. Often these simple foods are more filling and require less packing.
What to Wear
Just in case it's necessary to say, don't forget to wear sunscreen! Hats and sunglasses are also highly suggested.