I believe it BUT just to a certain extent.
For example, there are people healing certain conditions through fasting, intermittent fasting or raw foods (I know a person who had a great cancer remission eating raw foods; now he eats whole foods but still a lot of raw and barely no medicines, he looks great).
About Atkins and other meat based diets I feel very sceptic; but mediterranean, raw foods, fast-5, eats stop eat, calorie cycling, etc make a certain sense.