Lean meats (turkey, fish, chicken), eggs (or whites if watching cholesteral really closely), I found powdered peanut butter called PB2 (look it up online, it has only 54 cal/2.8
fat per 2T). However, one of my favorite little additions is parmesan cheese! For 1T, it's only 20 cal and has 2g protein. I always add it to my green beans, try it they taste great!