But the average food stamp recipient scored even worse: 47 out of 100 in one study, and 51 out 100 in another. Their scores were even lower than what low-income people not in the program got on average: 51 out of 100 in one study and 57 out 100 in the other.
Andreyeva stresses that her findings, which appear in the October issue of the American Journal of Preventive Medicine, don't mean people on SNAP make particularly bad food choices. Rather, they likely reflect the reality that the people who turn to SNAP for help tend to have the most limited means. Indeed, she found that both adults and children on SNAP were less likely to eat three meals a day than higher-income people not enrolled.
"It's hard to eat healthy on a very limited budget," Andreyeva says, especially when the cheapest food is often packed with calories but not necessarily nutrients, and many lack the time and skills to cook.
About 14.5 percent of Americans — some 46.5 million people — rely on food stamps. And at a time when more than one-third of U.S. adults are obese, she hopes her research will prompt lawmakers to consider how SNAP can address not just hunger but quality nutrition.
While the move toward healthier eating habits takes hold among wealthier Americans, Andreyeva worries the poorest among us will get left behind.
"Overall I feel that diets are improving slowly," she says. "My concern is that they're not improving at all or at slower rate among SNAP participants."
Take, for example, sugary drink consumption. The studies she looked at came to different conclusions on the question of whether SNAP recipients drink more soda than everyone else. But she notes that research published just last month — too late to include in her review – found that people on food stamps got 12 percent of their daily calories from sugary drinks, versus 6 percent for higher-income people. This finding comes even as overall soda sales are declining in the U.S.
Now, the U.S. Department of Agriculture has been experimenting with incentive programs to encourage healthier eating habits for people on SNAP.
For instance, as we've reported, the agency is investing $100 million in Double Up Food Bucks, a program that doubles the value of SNAP benefits when people use them to buy fruits and vegetables at farmers markets.
And USDA also helps fund education efforts like Cooking Matters. The program teaches low-income families how to cook and shop to get the most nutritional bang for the buck – by buying frozen versus fresh vegetables, for example, or focusing on the price-per-unit rather than the total price when comparing two items.
Across the U.S., hundreds of nutrition education and incentive programs are being implemented, says Ruth Morgan, an analyst with the Altarum Institute who helps evaluate food assistance programs for the USDA.
"There's been a push on USDA side to see what's working. Everyone is reinventing the wheel," Morgan says.
But these incentive programs are run by states, so the USDA's Food and Nutrition Service says it's hard to know just how many hungry Americans on SNAP they're reaching.
Copyright 2015 NPR.