movie where a man's stomach sloshes

When beautiful Carla Purty joins the university faculty, genetic professor Dr. Sherman Klump grows desperate to whittle his 400-pound frame down to size and win her heart. So, with one swig of his experimental fat-reducing serum, Sherman becomes 'Buddy Love', a fast-talking, pumped-up, plumped down Don Juan.

A timid, nearsighted chemistry teacher discovers a magical potion that can transform him into a suave and handsome Romeo. The Jekyll and Hyde game works well enough until the concoction starts to wear off at the most embarrassing times.