"Because meat is so dense in calories, it makes sense that vegetarian diets would be lower in overall energy -- making weight management easier."

I find this hard to believe. 4 ounces of meat has 100 calories in it which isn't much. If I were to try and eat as much chicken as I could or as much bread as I could. I bet I could eat a lot more calories in bread than I could in meat.

Also on the weight management part I have seen a lot of vegetarians and vegans that eat so many excess calories usually carbs that they are even obese. Possibly the people who ate meat had more muscle because those people were taking in adequate protein?