Most nutritionists do not know how food is produced – on the farm or by processors. Although fortification of processed foods has eliminated most vitamin deficiencies in the US, many in nutrition now recommend elimination of this entire category of foods. Such recommendations are often made without critical thinking, relying on emotions instead of data making this topic timely. A framework and case studies for critical thinking skills will be presented. The framework is grounded in academic research in cognitive psychology. It emphasizes three dimensions of critical thinking: 1) Diligent clarification to make sure that claims of fact are unambiguous and comprehensive, 2) Slow thinking to allow appropriate inference based on logic and probability, 3) Humble self-reflection to ensure a distinction between what is known and what is not known, and to express uncertainty honestly and consistently. The framework can be applied to both public and professional debates about nutrition science.