The aim of this study was to evaluate the responses of meat-type chicken to changes in dietary energy sources by comparing high-fiber high-fat vs. standard high-starch diets and using a transcriptomic approach in three major metabolic tissues - liver, adipose tissue and muscle - as well as in circulating blood cells. Overall design: 48 broilers from two experimental lines divergently selected on abdominal fat content (fat and lean lines) were fed with two different diets (high-fiber and high-fat diet (HF) versus standard high-starch (LF) diet).