The hunger games as the key to happily ever after?

The world’s human population is reaching record longevities. Consequently, our societies are experiencing the impacts of prolonged longevity, such as increased retirement age. A major hypothesized influence on aging patterns is resource limitation, formalized under calorie restriction (CR) theory. This theory predicts extended organismal longevity due to reduced calorie intake without malnutrition. However, several challenges face current CR research and, although several attempts have been made to overcome these challenges, there is still a lack of holistic understanding of how CR shapes organismal vitality. Here, we conduct a literature review of 224 CR peer-reviewed publications to summarize the state-of-the-art in the field. Using this summary, we highlight the challenges of CR research in our understanding of its impacts on longevity. We demonstrate that experimental research is biased toward short-lived species (98.2% of studies examine species with