You are right, that would be terrible advice. On the other hand that's not what he posted (although you can certainly read it that way if you want to.) I read

You are right, that would be terrible advice. On the other hand that's not what he posted (although you can certainly read it that way if you want to.) I read it more as "there's no one true diet" which seems to gel with my personal observation. The best exercise is any exercise you actually do - the best diet for you is one that is both healthy, and that you can adapt to. Small adjustments are more likely to "stick", and doing something small can be beneficial. For example, I'm not going to entertain "go vegan". That's too big a jump. But cutting down on meat is achievable. I'm not going carb free overnight, but I can start to reduce sugar (no sugar in coffee for example), eat more nuts for snacks, and less chips, and so on. I can do a "carb free month", I can reduce portion sizes. Ultimately my balance will be different to the next person's.