Always keep in mind that you may see improvements in health outcomes simply from being the kind of person who deliberately starts a diet she believes is healthy. (The same phenomenon that makes all kinds of education experiments perform well because the most motivated parents and children sign up.)
Always keep in mind that you may see improvements in health outcomes simply from being the kind of person who deliberately starts a diet she believes is healthy. (The same phenomenon that makes all kinds of education experiments perform well because the most motivated parents and children sign up.)