In this review, we discuss strengths and limitations of a recent rigorous systematic review and meta-analysis of the literature on associations of all-cause mortality with overweight and obesity. A perspective on its meaning and potential implications are provided. To move this field forward, we suggest modeling BMI as a continuous variable, switching to modeling longevity instead of mortality, and generating large publicly available datasets in broad and diverse populations for discerning the extent to which the BMI-mortality relationship differs between groups and over time. Randomized studies of obesity-related interventions that provide assessments of their actual effects on lifespan or mortality would have great value for helping to establish valid clinical and public health recommendations around weight loss and mortality. © 2013 Elsevier GmbH.