A recent New York Times article, What Really Makes Us Fat, highlights how scientific research may sometimes lead us to wrong conlusions.
In terms of diet and nutrition, as the results of research roll in, science is beginning to agree that the food behaviours humans had for thousands of years (higher fat & protein, lower carbohydrates) were better than the typical high carbohydrate (and fructose!) diets of the last 50 years – contradicting some of the advice that had come from earlier research.