"It's a trend that we're seeing with all of New Zealand, everyone's buying more food and drinks out, takeaways, but millennials seem to be doing it more than anyone else."
Millennials allocate around 20 per cent of their budget to eating out, while those aged over 30 spend just 12 per cent.
Last year they spent almost twice as much money on takeaways as they did on clothing, with takeaways accounting for 8.2 per cent of their retail spend.
Boles de Boer said she had expected to see an increase spending by millennials on food, but not as large as the data revealed.
Millennials spend 10 per cent of their total expenditure online, up from less than 5 per cent eight years ago.
Last year, online spending by total New Zealand population increased by 12 per cent over a year prior. For millennials, online spending increased by just over 20 per cent for the same period.
This highlighted the growing trend of convenience and the rise of meal subscription services, she said.
According to a Canstar survey released last month, 82 per cent of millennials use a meal delivery kit for convenience and 73 per cent believe they spend more money on meal kits than they would buying the food from a supermarket.
"One of the main motivations for them is convenience, millennials like having everything instantly, made for them and they don't like possibly the time it takes to cook a meal or go grocery shopping," she said. "We're seeing more groceries being bought online, more online shopping and more takeaways."
In the year ending December 2009, millennials accounted for 6.8 per cent of total national retail expenditure. Eight years later, this total value has increased by 56.2 per cent - now accounting for 7.4 per cent of total national retail expenditure.
We're seeing more groceries being bought online, more online shopping and more takeaways.
Retail consultant Chris Wilkinson said busier lifestyles, increased focus on leisure and vast hospitality options were driving increased spending on food.
"Millennials are all about the now and experience is a key part of this. Look at any bar and restaurant in the cities or provinces and it's millennials who often make up the majority of customers," Wilkinson said.
"We are seeing continuing creep of traditional retail space [move] toward food and beverage use - food halls will be the next big trend. These curated spaces with local and artisan businesses will increasingly populate larger, characterful spaces once occupied by retailers - creating micro 'communities' within cities or towns."
Food and beverage outlets were now assisting traditional bricks and mortar retail.
"We're finding the trend is assisting retail as demand and ritual for food and beverage keeps consumers closely connected and engaged with towns, cities and shopping centres - drawing people past shopping destinations on a regular basis.
"Given continuing competition from online, it's important people still find a relevance and reason to visit commercial centres - helping drive the likelihood of other purchases on their journey."