South Islanders have more traditionalist habits around the festive season, slightly more likely to serve turkey on Christmas day, compared to North Islanders who veer slightly more towards salmon.
Emily Blumenthal, Foodstuffs New Zealand head of customer experience, said shoppers in the two islands had distinct buying habits.
Brett Ashley, Countdown's acting merchandise manager said buying patterns were quite distinct.
"The South Island, in particular Canterbury, is the most traditional part of the country when choosing what to eat at Christmas. Cantabrians buy more ham or turkey with roast vegetables than any other region in the country. They also buy more pavlovas and cream than any other region and are the second largest consumers for cherries and strawberries," Ashley said.
Blumenthal said: "A leg of lamb is more popular in the North Island than the South Island at 19 per cent versus 16 per cent, followed closely by salmon, surging in the North Island as the next most popular choice, while turkey remains a favourite with South Island customers as their second most popular main," she said.
Using aggregated data sourced from New World Clubcard, Foodstuffs found other differences.
"It's not just the protein that differs between islands, it's also all the condiments and bits and pieces that go with it. Southerners are more likely to opt for the traditional clove- studded ham while North Islanders roll out the hot English mustard for an added kick on Christmas Day. Northerners are twice as likely to add a couple of relishes to the festive table for their ham," Foodstuffs said.
Ashley described many differences and was even more specific about regional variations.
"Wellingtonians prefer to create a barbecue meal based around a roll of eye fillet or salmon than any of the traditional meats but families in Masterton are more partial to turkey for their Christmas festivities," he said.
Salmon is the meal of choice for Aucklanders.
"The North Shore [residents] are high consumers of meat at Christmas preferring to have eye fillet or beef roasts as part of the Christmas meal and like to include a traditional Christmas pudding for dessert," he said.
"The Far North loves lamb and sausages for Christmas and also have a sweet tooth as one of the largest regions to choose pavlova and cream for dessert," he said.
Residents of the Waikato are big fans of the leg of lamb, eye fillet roll or beef roast as well as loving a pavlova for dessert.
"Cherries and strawberries are the top choice for Aucklanders and help bump bananas off the top grocery product list in December.Taranaki [residents] love a glazed ham at Christmas with salads and seasonal vegetables and for dessert, it's everyone's favourite pavlova," he said.
"South Canterbury is also very traditional with their Christmas meals; turkey and ham. However, a leg of lamb is the number one choice. Christmas pudding is their dessert to end their meal," he said.
Blumenthal said older customers preferred traditional favourites like fruit mince pies, puddings and Christmas cake. Younger customers were more likely to make ambrosia as a dessert, she said.