I'm a little confused as to why you're being down-voted, save your audacity in being cautious about nutritional "experts" having a poor track-record in their dissemination of advice. Mere decades ago, the statement that a high-protein/high-fat diet is optimal would fly in the face of expert-opinion. It is not so many years ago that using trans-fat laden vegetable oil was considered "healthier" than using rendered fat.

You have stated in a common-sense way that ingesting huge quantities of sugar and trans-fats make you feel terrible, and ingesting leafy greens make you feel physically well; not that one should simply eat what their cravings tell them to. As sensitivities to certain foods can manifest themselves in different ways on an individual level, recommending that people pay close attention to the impact that certain foods have on their energy-levels, mood, and performance is sound advice.