Protein is relatively calorie dense but without bad “reputation”. Here are some lesser known facts, based on https://www.webmd.com/fitness-exercise/guide/good-protein-sources

• egg white — one of the least expensive proteins.
• poultry is usually more lean than dark meat, esp. with skin removed.
• seafood is more healthy than white/dark meats. Even the fats are healthy fats.

I want to try high-protein foods and see if they offer a good satiation/calorie ratio. I feel to reduce my BMI, I have to eat a lot of fruits/raw veg, and reduce everything else including protein.

Most high-protein foods have a lot of fat or starch :(. Here are some rare exceptions

• whey
• low-fat milk? can mix with other drinks
• tuna in water
• turkey without skin
• lean ham at 50 cal/56g