To show that it's an intervention that works and to support other conclusions. Wildly applicable? I doubt. But there is no-one-size-fits-all solution.
Sure, you can propose Atkins or similar, but then you might want to consider the cardiovascular implications.
I was about to write that it isn't simple. But to be honest, it is simple. Eat well and exercise. Simple isn't, of course, always easy. But frankly at the moment, if there's 20:1 ratio of treatment vs. prevention, we aren't really even trying. But then we have a government that is scientifically illiterate and in thrall to the junk food and drinks industry. And a population that doesn't want to be told it can't have its cake and eat it and then come back for seconds.