Putting on the feed bag is an informal phrase used to describe eating a large meal, often with enthusiasm. There are several synonyms for this phrase, including "chowing down," "digging in," "stuffing your face," "gorging," and "pigging out." Each of these phrases essentially communicates the same idea: that someone is eating heartily and with gusto. However, each phrase also has its own unique connotation. For example, "pigging out" suggests a lack of moderation or self-control, while "chowing down" has a more casual, laid-back feel. Ultimately, the synonym you choose may depend on the tone you want to convey.