The world’s human population is reaching record longevities. Consequently, societies are experiencing the tangible impacts of prolonged longevity, such as increased retirement age. A major hypothesised influence on ageing patterns is resource availability and calorie restriction, considered by many to extend longevity in any organism. Here, we highlight challenges facing the field of calorie restriction research as it pertains to ageing and how more realistic environments can impact the role calorie restriction plays in longevity of species. We reviewed 120 peer-reviewed published studies to quantify calorie restriction effects on longevity. We show that calorie restriction research does not always have positive effects on ageing with 27% of studies having no, negative or neutral effects. Additionally, research is biased towards short-lived species and lacks realism. We argue that only by taking a more realistic approach can the impacts of calorie restriction on longevity under climate change be understood. We conclude by discussing Planarians and Hydra as model species that allow for future research to have a better understanding of calorie restriction effects on long-lived species, while incorporating climate change impacts. Steering future calorie restriction research towards integrating interaction effects across a broader range of species will begin addressing the challenges of calorie restriction research. Crucial insights from future research can contribute to the fundamental and translational understanding of human senescence.