I would always mix it up. For example breakfast a protein source could be eggs , mid morning snack a whey protein shake, lunch red meat, dinner chicken etc... I think its best not to eat red meat every day but it definitely has its place in my diet atleast 3-4x a week. I'm sure you could eat it every day, probably even for every meal if you would really like to. But since beef is pretty expensive per lb. i tend to buy it less than chicked tuna etc.