this is why overseas there is a big culture around having large refrigerators and effective food storage. you will see a household have several large refrigerators stocked with frozen meat, or vegetables stored properly in tupperware containers. this is why the small apartment/house sizes in japan shock foreigners. because they think "where do they store their food?". the main reason why they only do groceries once a week is because supermarkets are almost always a far distance from your house. 2-3 hours away by car. it is more convenient for them to just buy a lot in bulk, then store it.