"Eat meat and vegetables, nuts and seeds, some fruit, little starch, and no sugar. Keep intake to levels that will support exercise but not body fat." - Greg Glassman
"These two sentences capture a nutritional approach that, when applied with our workouts, yields incredible health and fitness." - CrossFit
Sure there are other things you can eat and be totally fine. It depends on each individual and their goals.
Rice is fine. Oats are fine. Bagels are fine. A night out with some friends for drinks and wings is totally fine.
But the idea is to create a lifestyle and nutritional approach that is centered around eating real, whole foods.
This type of approach will give you the best energy, nutrients, and amino acids to fuel your performance so you can get stronger, build muscle, and lose weight.
Commit for 6 months and analyze how you look, feel, and perform.
What's the worst that can happen?