Sales at supermarkets across the country increased by more than 27 per cent in the four weeks of level 4 lockdown ending April 19.
Nielsen's Scantrack sales data shows grocery items across all categories were up significantly during the month of the strictest lockdown requirements compared to the same period a year earlier.
There were, however, a few categories that experienced a decline in sales over that time.
Sales of boxed hair dyes - once on the decline - increased by more than 100 per cent over the four weeks compared to the same period earlier, while home brewing kits and concentrates increased by 94 per cent.
Not surprisingly, the sales of cleaning products, supplies and disinfectants increased by almost 70 per cent.
Baking products such as eggs, butter, flour, sugar, baking powder and cooking chocolate experienced a 53 per cent increase in sales during that time, while canned and convenience foods such as soups and frozen meals sales increased by 64 per cent.
Coffee product sales increased by 37 per cent and the sales of alcohol increased by 36 per cent compared to the same time last year, this could be attributed to the closure of pubs, bars and liquor store closures, Nielsen said.
Hair styling products were one of the few grocery products to experienced a decline in the first four weeks of lockdown, sales of these decreased by 36 per cent as the need to leave the house over that time was restricted to essential outings such as a trip to the supermarket and visits to the doctor or dentist.
On the go snacks and items that would typically be found in a lunch box such as muesli bars, cereal bars, snack balls, baked bars and nutritional sports bar experienced an almost 30 per cent drop.
The four weeks ending April 19 also included the school holidays, which were brought forward, so this could also be attributed to the decrease in sales.
Despite an initial increase in sale of bottled water, overall over the four weeks, sales of bottled water decreased by 16 per cent.
A month earlier, in the three weeks to March 15, sales of toilet paper at supermarkets increased by 87 per cent, this followed a surge in sales of household cleaners and facial tissues, up 76 per cent and 67 per cent, as initial concerns of Covid-19 set in.
Within food retailing, rice experienced the biggest surge in demand from shoppers in recent weeks following the outbreak, with sales up 69 per cent compared to the same time last year.
Online retail sales at grocery and liquor stores were up by 42 per cent in the month of March, according to BNZ. This followed a 10 per cent increase in spending at pharmacies and within the cosmetics categories.
Total sales online across all categories were up 6 per cent in the month, with spending at domestic sites up 24 per cent and international sites down 18 per cent.