The challenge is that diets that rely on how your body metabolizes certain foods inherently depend on a lot of details about your digestive and metabolic proces

The challenge is that diets that rely on how your body metabolizes certain foods inherently depend on a lot of details about your digestive and metabolic processes. Some of those things probably are very generalizable, but many of them will vary widely in how well they work depending on genetic factors, gut flora, and lifestyle. By contrast, calorie counting requires only that you obey the laws of thermodynamics. At some level of reduced intake it will produce weight loss for literally anyone. Having said that, if not eating carbs gets you there that's great-- I don't want to diminish anyone else's experience with weight loss. I just think more people should be up-front when talking about their new diet that any surprisingly easy way to lose weight is surprising because things don't normally work that way.