Enough protein is the only way to reduce calorie intake without rampant hunger which will bust the diet. In fact the key determiner of whether a diet is sustainable is whether it gives a person at least 75 grams of protein a day. Lean meat is the best way to get it.
However, meat is not an essential part of each meal. Veggies and grains are much healthier than having bacon for breakfast, a turkey sandwich for lunch, and meatloaf for dinner. I don't think our bodies can process that much meat in a day.