Tights, sunglasses and boneless chickens have joined the list of casualties of America's economic crisis, as the era of impulse shopping gives way to more wary behaviour in the nation's grocery aisles.

Americans unwilling to pay extra for their food to be prepared bought $65m more whole frozen chickens in the third quarter than a year earlier, and $50m fewer boneless birds, according to a study of store loyalty card data covering 250m transactions a week.

“Instant gratification” categories such as sunglasses and tights registered some of the steepest declines in the study by Catalina Marketing, which gathers loyalty card data from 40,000 US supermarkets and pharmacies representing $800bn of US consumer spending a year.

Eyewear was down 43 per cent in unit terms, while 29 per cent fewer packs of tights were sold as women “took better care of the tights they had already purchased”, according to Marla Thompson, Catalina's vice- president of national accounts.

Men, keen to look sharp in the office as the country faces its highest unemployment rates for a generation but unwilling to spend on the salons that had enjoyed a male grooming mini-boom, bought 28 per cent more hair-care products at grocery and pharmacy chains.

“The old world was about instant gratification, but in the new world consumers are making a shopping list . . . They're less impulsive,” Ms Thompson said. “Changes in shopping behaviour suggest some new habits may be emerging.”

The complex interchange of financial and emotional impulses is being felt even by the nation's cats and dogs as consumers traded down from “wet” pet food, but then supplemented their animals' more basic diets with snacks “so they still feel good about it for their animals”, Ms Thompson said.

The study identified other changing habits with implications for retailers, consumer goods manufacturers and marketers. A trend away from eating out led to a 70 per cent jump in the number of ice cream cakes sold, as more children's birthday parties took place at home. Ready-to-eat popcorn purchases were up 55 per cent and sausage dinners up 27 per cent as more evenings were spent in front of the television.

Popcorn and sausage dinners notwithstanding, some Americans remain willing to pay up for a healthier diet. So-called performance drinks, such as protein smoothies and vitamin-enhanced water, were up 67 per cent, or $7m, at the expense of cola sales.