One additional argument against Atkins and LC that I have often heard is:

All diets end up being the same, they work because they restrict what you can eat, and therefore you eat less. A calorie is a calorie, and Atkins restricts what you can eat enough that you end up eating less because it is boring.

That is an argument I hear a lot from nutrionists etc., and it is worth discussing. There are four arguments, at least, against it:

One: it is a difference whether you are hungry on a 1200 calorie diet or not. Atkins and other LC diets work in part because fat and protein don't leave you hungry as quickly, so even with the same amount of calories, you can be hungry or not. Obviously, LC dieting is popular because you don't feel hungry, in contrast to slim fast or many low fat diets.

Two: "starvation mode" : When your body is in starvation mode, it uses a calorie given much more efficiently than when the body feels normal. That is one major reason why several recent studies show that LCers eat more calories and still loose more weight. We are making our furnace less efficient!

Three: Insulin and glucose yoyo: you can read up elsewhere - I don't want to bring that whole physiology here again, why the yoyoing of glucose and insulin is bad and how LC maintains a balance of both.

Four: Ketones. You can get the details elsewhere but the bottom line is: If you pee out some of the calories as ketones, they don't count against you.