My personal feelings about carbs and protein are that it really doesn't matter if you eat them together or not. I know that Slimming World swear by their red and green days etc, but my own opinion is that, no matter what you are doingm to lose weight - counting points, red and green days, etc - at the root of it all lies the fact that you are eating fewer calories and less fat. For instance, on a Slimming World green day, you might be eating pasta, rice or potatoes - all low in fat. Since you cannot have cheese on a green day, you'd be having tomato-based sauces on your pasta which are naturally lower in fat. On a red day, you are eating protein and vegetables. The rules state that meat must be lean so there won't be too much fat and we all know that protein aids weight-loss, especially when exercising as it helps build lean muscle which helps the body burn fat more efficiently. I personally don't feel there is any scientific reason behind any of it other than the fact that, which ever method you choose, you are eating fewer calories and less fat. Simples.