https://www.sciencedaily.com/releases/2021/10/211005175402.htm

Some countries have introduced mandatory front-of-package labeling in hope of improving people's diets and reducing the burden of diseases associated with poor diets. These labels may employ color coding to indicate nutrition, or they may warn consumers about unhealthful features of products. However, studies on the impact of such labeling have produced mixed evidence.

To help clarify the impact of front-of-package nutrition labels, Song and colleagues analyzed data from 134 peer-reviewed studies published between January 1990 and May 2021. They applied an analytical method known as network meta-analysis in order to integrate the results of the studies and evaluate the impact of four different labeling systems -- two that use color-coding and two that use warnings.