That's annoyingly normal - he went vegan, feels great and thinks everyone should try it for a week, now drinking milk and eating meat makes him feel ill.<p>He doesn't explore though; could he be feeling better simply from eating less? Or more? Or more greens, or more of a particular nutrient? Or less of one specific thing he doesn't digest well? Or does the change in diet make him sleep differently and that's why he feels better? Is it just the act of change itself that does it?<p>And does he now feel bad about eating animal products and that makes him respond badly? In the comments he refuses to test it and isn't interested in finding out. Does raw animal produce do the same? Unpasteurised milk, raw meat or fish? What about goat or sheep milk? Or byproducts?<p>I am of course interested in the mysterious weight which lifted from him such as the "annoyance of getting out of a chair", but all sorts of strange practices practitioners claim unverifiable things like that.<p>Does anybody like this measure anything quantitatively?