By Karina Shah

Consumers in the US spend more money when grocery shopping online, but spend less on sweets and desserts than when they shop in store.

In recent years, online grocery shopping has grown massively. Since the beginning of the covid-19 pandemic, the amount that consumers spend through online shopping has more than doubled in the US.

Laura Zatz at Harvard University and her colleagues have investigated how people’s habits change when they are spending in store versus shopping online. They recruited 137 participants from two supermarkets of the same chain in the US state of Maine. Each participant was the key shopper for their household, and they also had experience shopping both online and in-store.

The researchers studied each participant for a total of 44 non-consecutive weeks and tracked what items they purchased between 2015 to 2017. They collected data from a total of 5573 transactions, 1062 of which were made online and 4511 in store.

“We found differences in both the quantity of foods that people purchased and the types of foods that people purchase when they’re shopping online versus in store,” says Zatz.

People spent more money on sweets and desserts when shopping in store, spending on average $2.50 more per transaction. However, there was no difference in spending on sugary drinks or salty snacks, such as crisps.

“They purchase more items [when shopping online], both in terms of overall number of items but also a greater variety of unique items,” says Zatz. On average, participants spend 44 per cent more per transaction when shopping online than in store.

It seems that in-store shopping entices shoppers to unhealthier food choices. “When you are in store, you are exposed to all sorts of stimuli that could encourage you to buy unhealthy impulse-sensitive food groups when you might not have otherwise planned to,” says Zatz. Unhealthy food choices are often displayed in supermarkets at the end of aisles and at checkouts to encourage unplanned purchases.

The findings could help to inform us about how to encourage healthier food purchasing choices, especially as sophisticated marketing is coming online, says Zatz.

Charles Spence at the University of Oxford is surprised there was no difference in the purchases of “olfactorily-tempting foods”, such as freshly baked bread and coffee. “[They did not] suffer in the online environment, given the absence of smell,” says Spence.

Journal reference: Journal of Nutrition Education and Behaviour, DOI: 10.1016/j.jneb.2021.03.001