Union Township, New Jersey police said 38-year-old Kiana Workman, who had been deceased for at least four days, died sometime last week of undetermined natural causes.
The boy, according to PIX11, weighed just 28 pounds -- about 16 pounds underweight -- and had been surviving on sugar because he was unable to open the door of the well-stocked refrigerator.
The child was "alert, spunky and talkative," police said, but taken to a hospital and treated for dehydration.
Neighbors told police the boy's grandmother had been hospitalized with a broken hip, and that the mom had not looked well for months.
"I know she was sick," one neighbor told PIX. "I haven't seen the lady since January."
The boy, who police said was rubbing lotion on his mother's skin in an attempt to care for her, is expected to make a full physical recovery.
Authorities were having some trouble finding Workman's brother or other relative to determine where the boy will live. People across the country have reportedly been calling Union trying to adopt him.