Evidence-based medicine has become accepted as the preferred way to develop clinical practice guidelines for nutrition care. The distinction between nutrition care (ie, medical nutrition therapy) and population dietary guidelines is becoming increasingly blurred. The evidence analysis systems used to develop Medical Nutrition Therapy Guides for Practice, as well as other medical care guidelines, are reviewed. The identification of various methods that evaluate individual research reports and various systems that specify the strength of the evidence supporting a recommendation/conclusion statement are included within the article. The potential application of these systems for development of national dietary guidelines is introduced.