Several big grocery chains have developed their own store brands of natural lines of organic products that "allow consumers to trade down" without changing their diet or food quality.
"People do want to get healthy, but they also want to be smart shoppers," Hauptman said. "So, traditional supermarkets have jumped on this opportunity by providing less expensive lines of products these consumers need."
David L. Katz, associate director of nutrition science at Yale University's Rudd Center for Food Policy and Obesity, said it's too early to tell how the downturn will affect people's health.
"I think there's real cause for worry, because the data we do have, in general, indicates that more nutritious foods tend to be higher priced. It's only going to compound that problem [when] the food prices rise," Katz said.
In general, he added, "poverty is associated with poor quality diets and increased rates of obesity, diabetes -- all the bad stuff."
There are some healthy food options Katz recommends for budget-conscious shoppers:
Lentils and beans are a good protein substitute for meat.
Cooking grains, such as brown rice, bulgur wheat and barley are cheaper and healthier alternatives to cereal grains that don't need preparation.
Store brands can rival name brands in nutritional value, but check their labels to be sure.