To get a free vacation, the girls apply to be counselors at a 'fat farm'. A nasty female trainer named Bambi wants the jobs for her sisters and takes revenge by giving the two harsh tests of will power against eating. It's do or diet.

Shirley's sailor brother returns but he's not the Brother Shirley remembers. He's developed a drinking problem. He denies he's an alcoholic & just likes to have fun but Shirley's determined to bust him out from the bottle.