Critical Evaluation of Nutrition Research

Abstract

Despite the increasing focus placed on the importance of nutrition for optimal health, nutrition as a science is often criticized in lay media and casual conversation as constantly conflicting with itself, and experts ridiculed for seeming to change their minds. Although there is much that is uncertain about the effects of foods on health, the seeming contradictions can come from misunderstandings of nutrition science. This chapter is designed to be a primer for readers of scientific literature to identify some of the challenges in evaluating what was studied, determining how it was studied, and interpreting what we can conclude from studies. In this chapter, we will consider: challenges in defining exposures and outcomes, oversimplification of complex concepts, differences in causal inference from a variety of study designs, surrogate and hard endpoints, bias, confounding, letting data speak, logical fallacies, and the differences between scientific conclusions and evidence-based decisions. The points discussed herein should help the reader to look at nutrition research with a more critical and discerning eye, which will aid in distinguishing between when scientific findings disagree and when the studies are actually asking distinct questions.