Coach Nack is about to say something borderline controversial: fat doesn't make you fat, sugar from carbohydrates does (or too much fat with too much carbohydrate will also make you fat). That said, eat fat and enjoy it. Fatty foods often taste delicious, but just make sure you are eating the right fats.
Here are some fatty foods I recommend you eat:
Almonds, pecans, walnuts and other nuts and seeds- (a peanut is not a nut, by the way, so remove it from this conversation) The great thing about nuts is that they are easy to have around. Anyone can carry a bag of almonds with them, and can benefit from the awesome energy boost they can provide. All athletes should have these in their "Go Bag" when they are competing at a meet.
Almond butter- this is the creamed form of the nut mentioned above. This is a preferred option to peanut butter, because of the better health contents within the spread. Find some almond butter, and bring it to meets to put on fruits, vegetables, or even some bread (that last one pains me to say).
Olive Oil- Always try to go with extra virgin olive oil, or EVOO as we used to call it in the restaurant biz, because it is less refined then its counterparts. The one thing about EVOO is that it is hard to carry around, and hard to decide which foods to eat it with, so bringing it to meets may be unrealistic. I would simply suggest replacing the dressings on your salad with this (try a mix of EVOO, red wine vinegar, salt, and pepper; it might not have the taste of your ranch dressing, but you will feel better and your performance will improve). EVOO is great not just on salads but on any vegetable. Let yourself get used to it for a couple weeks, and I can almost guarantee you will love it. Like nuts, this is another great energy booster, as well as an appetite suppressant. In fact, ultramarathoners (100+ Miles) carry tubes of olive oil on them and pound down shots of olive oil as the only means to get them through their events.
Coconut milk- Yummy, yummy, yummy! A million things to do with this, but I would recommend adding around 4oz of it to our post workout protein shakes.
Avocados- you might have hated these things as a kid, but make a return to it and you might just love it (I speak from personal experience). What self-respecting adult doesn't enjoy some delicious guacamole every now and again?!?
Meat- This should primarily be considered a protein source, but it can be a good source of fat, when the source is fish. Fish contains a healthy amount of Omega-3 fatty acids that are essential to our well being as people.
Avoid these things when looking for good fat sources- French fries, things cooked with vegetable oil, donuts, potato chips (my weakness), lard, butter, dairy fats(I question this for young athletes), margarine, and shortening.
To wrap it up I would tell you to learn what good sources of fat are, get some in your kitchen pantries, add some to your "Go Bags", and see what fat can do for you. Fat is probably the most misunderstood macro-nutrient we consume. Almost everyone presumes that fat is bad, because "it makes you gain weight" or "it causes heart attacks" , but I assure you that fat is fine when you take it from good sources, and eat it in moderation along with carbohydrates.
Nack
Note: if you are interested in the debate of the effects of fat compared to carbohydrates in the human diet I would recommend Gary Taubes' book Good Calories, Bad Calories. It is a book that will make your head spin with its thoroughness, and ability to make you say "wow! I never knew that." I definitely recommend this book for those of us over 30 wanting to know a little (rather a lot) about diets. Here is a good interview with Taubes where he talks about many things, including his findings over fat consumption and the poor science that has gone into labeling it as a killer.
