One of the principles of clean eating is to eat 5-6 times a day, including a lean protein and complex carbohydrate in each meal or snack. But why the combination of carbs + protein?
For one thing, it helps me feel like I'm having more than just a mindless munch. Combining fruit and nuts with cheese, or chicken with vegetables, makes it feel more mini-meal-ish. Not only does it physically make me feel more full, it also works mentally. Knowing I just ate a real, solid combination of good, clean foods rather than just a handful of pretzels or a single piece of fruit encourages me to *not* keep eating.
On a more scientific note, according to Tosca Reno in The Eat-Clean Diet Recharged, "Eating protein causes your metabolism to speed up as a direct result of the numerous chemical reactions required to digest protein... Eating a meal that combines lean protein with complex carbohydrates causes your BMR to begin to rise within one hour. This increase lasts from three to twelve hours..."
Eating these mini-meals of carbs + protein helps your metabolism stay stoked all day long and keeps your blood sugar stable. The best part of that? No mid-afternoon crash! Once I started eating clean, I felt more energetic, calmer, and less mood-swingy. Now when I slack on eating quality carbs and protein throughout the day, I can definitely feel a difference. I'm more sluggish, less motivated, feel more tired, and have a general foggy-headed feeling. Not fun! I'd rather fuel up with carbs and protein and get on with life--I have things to do, after all, despite being semi-retired. :)