Waikato-based first home buyers were the most likely to slash their eating out spending with nearly half (49 per cent) doing so.
A third of first home buyers also cut-back on shopping and nearly one in four dropped their spending on personal maintenance which includes hair cuts.
Aucklanders were more likely to drop spending on home delivery including Uber eats and grocery delivery, gym memberships and subscription services like Netflix than the national average.
But first home buyers in the Hawke's Bay were the most likely to say they had delayed having a child or more children after taking out a home loan.
More than one in 10 (14 per cent) first home buyers surveyed in the Hawke's Bay said they had delayed having children compared to the national average of 5 per cent. The percentage for Auckland was 8 per cent.
Nationally 5 per cent also said they had delayed a wedding with 10 per cent of first home buyers in Whanganui/Manawatu and Taranaki saying they had done so.
Almost half of first home buyers in Auckland are borrowing more than five times their income to buy a house, Reserve Bank data released earlier this month has shown.
Jose George, New Zealand general manager of Canstar, said when people were borrowing so much money there were naturally going to be cutbacks.
"There will be some adjustments people have to make in lifestyle."
George said first home buyers wanting to impress the banks and get a better deal on their mortgage should look at trimming their spending ahead of getting a loan.
"We all know banks have become far more careful in the lending process. Anything that helps give confidence in the ability and the attitude to paying back money and saving more is going to help borrowers."
First home buyers make up nearly 20 per cent of the home loan market by value. George said it expected this to rise with the recent drop in home loan rates.
"However it is worth remembering that saving the required deposit to even get a home loan remains very difficult for many young New Zealanders.
"Our research shows some of the very big decisions they are being forced to make to the dream of homeownership come true."