Quantitative analysis of compensatory and catch-up growth in diverse taxa

1. Compensatory growth and catch-up growth are often used interchangeably to describe the faster than optimal growth that occurs following a period of dietary restriction in the development of many animals. Concerns about the statistical analysis of these studies have drawn attention to the risk of false detection in reports of compensatory and catch-up growth. 2. This study aims to quantify the degree to which these compensatory responses occur across the animal kingdom. In addition, this study distinguishes the two terms, 'compensatory growth' and 'catch-up growth', to clarify the fitness consequences of rapid growth. Compensatory growth refers to a faster than usual growth rate, while catch-up growth implies attainment of control size. 3. Eight meta-analyses and meta-regression analyses were conducted on data extracted from 88 papers, including 11 taxonomic classes. The results confirmed that both growth tactics (i.e. compensatory and catch-up growth) occur across a wide range of taxa and result in decreased direct fitness components. 4. Importantly, the meta-analytic methods used made it possible to identify the specific experimental techniques that most successfully promoted rapid growth after restriction and key differences in the responses of the four major groups (mammals, birds, fish and arthropods) to dietary restriction. Endotherms are more likely to show a compensatory growth response because of their determinate growth; in contrast, the indeterminate and saltatory growth tactics of fish and arthropods reduce the pressure to rapidly achieve a large size. 5. Among the first meta-analyses to be conducted in this field, this study provides valuable support for the premises of compensatory and catch-up growth and also discusses weaknesses in experimental design, and possible solutions, in compensatory growth research. For example, we recommend conducting the experiment within the most linear phase of an animal's growth to avoid analytical complications arising from size-dependent growth, and our results indicate that dietary dilution more closely resembles quantitative restriction than clutch size and intermittent feeding restriction methods when normal quantitative restriction is not possible.