"Where's my food?" he demanded.
When the victim said he did not have any, Lewis became aggressive, demanding he get some and smashed the driver's door window of the car.
And later that night, Lewis "aggressively" approached a couple in the Taupo Pak'nSave car park who were putting their groceries away.
He threw their trolley to the ground before pushing the man against the vehicle.
Shouting at him, Lewis pushed him again, which caused his head to hit the canopy, resulting in a concussion.
He then threw the man to the ground and held him there, demanding meat.
The victim's partner handed it over, and Lewis ran off.
At Lewis' sentencing in the Dunedin District Court yesterday, Judge Jane McMeeken said he had not been provoked and the victims were innocent people going about their lives.
"You frightened and hurt them," she said.
Judge McMeeken said it was sad Lewis continued to deny his bipolar diagnosis and not take prescribed medication.
"You seem to think that your mental health doesn't contribute to your offending," she said.
"Sadly Mr Lewis, you have a mental illness and the experts say you need to take medication for that illness.
"Not having treatment puts you at risk of hurting yourself and others."
Lewis was sentenced to one year's imprisonment.
