A common name to describe men who love bigger women is "chubby chaser." This name, however, is not gender specific; women who love bigger men can also be deemed "chubby chasers." Furthermore, the name is not solely used in the heterosexual community.
There are several synonyms of the term "chubby chaser," all of which vary in levels of political correctness and frequency of use. A couple of these synonyms include, "plumper" and "hogger." The woman being pursued due to her weight, moreover, may be anything from slightly overweight to enormously obese. The term is thought to have originated from the expression "chunky monkey."