I think this is like drink 8 glasses of water a day. If I did that there'd be no point in my ever leaving the bathroom! It's also in the same category as BMI recommendations. I'm quite thin. But whenever I've checked my BMI on different medical websites they say I'm in the middle of the range for my age, gender, etc. In order for me to get down toward the lower end of my BMI range, I'd have to be just some skin draped over my skeleton. Who comes up with these things?