I find that nuts are a convenient source of protein that is readily portable and doesn't require preparation.
Sliced almonds are nice...enough crunch to satisfy that need for crunch, without any fry oil and salt...
Throw a few into your salad, on oatmeal,...just about anywhere!
I like to take almond slices and dip them in Nutella! ...or cream cheese!
...but they are great, plain, too!
Not a fan of almonds? ...maybe pecans? ...walnuts? .....natural peanutbutter on a celery stick?