In regards to "lose weight cut carbs or fat" another paper looked at percentage of protein intake in a hypoenergetic diet (i.e. fewer calories than maintenance) in comparison to normal ratios. It suggested that a high protein diet "was significantly superior .... for maintenance of lean body mass in young healthy athletes during short-term hypoenergetic weight loss". Yes calories ultimately make a big difference but to say meal composition does not is clearly not true. The study in mentioned only looked at bodyweight and waist circumference and not at percentage bodyfat. It is feasible that the participants lost weight a significant amount of which was muscle. Not ideal for the aspiring athelete. Similarly protein takes more energy to digest than carbs or fat so the calories in calories out argument is somewhat of an oversimplification.