Well Meg pretty much said it all
For breakfasts I love to have an egg (a real one, not sub) between toast or an english muffin. Or when I have oatmeal I throw in a serving of walnuts. Both of those provide me enough fuel for 3ish hours, at which point I either eat a snack or lunch depending on the time.
Lunch protein... can be as easy as cooking extra chicken the night before and throwing leftovers on a salad. Or making a hardboiled egg and packing it with your lunch. Cottage cheese is another very versatile protein source that works well at lunch... Throw some on whole grain crackers with some tomato and pepper! Very yummy, lots of protein!
Snacks I always try to combine protein and carbs... if I eat an apple, I'll be hungry again in 20 minutes. If I eat an apple with a serving of cheese, I'll be set until dinner! Same goes with cheese and crackers, or cottage cheese and fruit.
Dinner protein sources are the most obvious, as we're kind of programmed to expect a large chunk of meat at dinner. Just watch your portion size, and downplay the carbs you serve yourself in favor of veggies.
There's definitely a balance to be struck. I don't think that anything that totally eliminates a food group for any extended period of time is sustainable, but that's me. Carbs and protein and fat are all important in your diet, and those Fitday guidelines are pretty standard. I am for the lower carb range and the mid-to-upper protein range, personally.
Good luck