The World's Fittest Countries Ranking (WFCR) is an unrivaled research-based tool to measure the fitness of a country. The 4 variables taken into account are the WRCES, the Obesity rate, the Prevalence of Undernourishment (PoU) and the WRCES Merit Ranking, which considers countries results in elite sports considering their wealth (GDP).
These variables (components) give an accurate inventory for governments to then implement the convenient policies to improve the fitness level of their inhabitants.
The WFCR score of a country will indeed allow the governments to know the levers that are allowing or refraining them from having a good level of fitness among their populations.
The International Federation of Physical Education and Sports (FIEPS, https://www.fiepseurope.com/), an organization recognized by the IOC and regrouping 142 countries, is currently investigating whether it will formally sanction this ranking.