BMC Nutrition is calling for submissions to our Collection on sugar's impact on nutrition and public health. The "Sugar Century" refers to the profound effect that sugar and high-calorie foods have had on human diets and public health over the past century. As sugar consumption surges, so too have the rates of obesity and related chronic diseases, prompting a critical examination of the role of sugar in our diets. This Collection aims to explore the multifaceted relationship between sugar intake, caloric consumption, and health outcomes, providing a platform for researchers to share insights into the historical, cultural, and biological factors that have shaped our current understanding of sugar's impact on nutrition and health.