LONDON – British shoppers are increasingly turning to convenience stores for more than just the occasional gallon of milk or loaf of bread.

According to new research from the U.K.-based consultancy him!, British consumers are buying an average of three products per trip, up slightly from 2.8 last year. About 20% of convenience store shoppers said they'd bought five or more items on their last visit, with an average spend of £6.52 (about $10.15), compared to just £6.05 ($9.40) in 2014.

"This is great news for convenience, as it shows shoppers are trusting them as a destination for bigger shops and for a broader selection of missions and categories," Katie Littler, communications director of him!, told news sources, according to a report on AOL Money.

According to the research, four in 10 c-store shoppers are topping-up between their main shopping trips, as they try to save money by targeting their spending. While convenience stores generally have higher prices than larger supermarkets, the strategy of topping-up often results in less waste and fewer impulse buys for shoppers, making it cheaper overall.

Many people are now visiting discount grocers for occasional big shopping trips, with the rest done locally on an as-needed basis. Indeed, according to him!, 30% of U.K. adults no longer do a main shop at all, instead shopping at several different retailers each week.

"UK adults use four different grocery retailers, on average, per month and this number is increasing," says him!. "Not only are we continuing to see shoppers do smaller, more frequent shops, but those smaller shops are now being spread thinner across a wider number of retailers."

This is a trend spotted by Sainsbury's, which says its smaller convenience stores, Sainsbury's Local, have seen a big surge over the last couple of years, and as a result, the company plans to double the number of convenience stores to 1,500.