A meal replacement should offer the user a good blend of carbs, fat and protein. For a 75kg male athlete (avg weight) wanting to retain/grow muscle, the macro break down of 2000 kcals would then be Carbs – 250g (50%), Protein – 150g (30%), Fat – 44g (20%). For fat requirements based on DRI, this is low. But in order to grow and maintain muscle, there must be sufficient protein. So protein has to be prioritised over fat. A meal replacement should be as close as possible to real food.