Thanks for the great question! What a trainer/nutritionist eats throughout the day is going to depend on their cultural views, fitness goals, and other health issues- just as it varies for all of you! I do think, however one thing most trainers and nutritionists agree on is eating 6-7 small meals every couple of hours throughout the day.
I personally try to eat fairly clean and organic- meaning predominately whole foods with the USDA Organic label versus processed foods (such as baked goods, breads, crackers/chips, salad dressings, processed meats, and sugary or salty condiments).
A typical day may look as follows:
Whole Oats, Falxseeds, Wheatgerm, and Blackberries
Turkey and Veggies
Apple with Peanut Butter
Shrimp with Lemon and Pepper
Salad with Balsamic Vinager, Chicken, legumes
Of course, I also drink water throughout the entire day. Eating clean does take a little more time to prepare your meals, however the rewards significantly outweigh the time lost in preparation.
I hope this answers your question!