With the current economic climate, it’s increasingly important to understand the relationship between food cost and nutrition. There has been a longstanding debate whether foods packed with calories, but low in nutritional value, are more accessible and affordable than foods that cost more but are more nutritious—especially for low-income individuals and families. A group of scientists in California and Washington decided to add evidence to the debate.????? ?

Researchers at the University of California – Davis and the University of Washington tested their hypothesis that lower-cost diets among low-income women would be higher in calories but lower in nutrients. Their tests concluded that the more energy-dense (high-calorie) the diet, the less nutritious it is likely to be. Additionally, low-income women who ate more nutritious diets spent more money per calorie than those who ate less nutritious diets.

The study recruited low-income women from four counties in California. Participants completed a food-frequency questionnaire that assessed consumption of 152 food and beverage items over the previous three months. The data was used to estimate intakes of energy, fats, dietary fiber, added sugars and vitamins and minerals. Energy density was calculated as kilocalories (kcal) per unit weight of edible food, and costs were estimated from local food prices.

Specifically, the survey showed the women reported a mean energy intake of 2,061 kcal per day and a mean dietary energy density of 0.94 kcal per gram. The consumption of a higher energy-dense diet was associated with higher intakes of fat and lower intakes of calcium and vitamin A. Mean daily diet costs were $6.11 per day, or $6.06 for every 2,000 calories. As cost increased, dietary energy density (calories), total energy, fat and sugar intakes decreased while vitamin A intake (nutrition) increased.

”Results of this project point out the need for nutrition guidance materials for low-income audiences. These new materials must include strategies for improving the quality of diets without increasing costs,” said Etta Saltos, CSREES national program leader for human nutrition. “USDA’s Expanded Food and Nutrition Education Program (EFNEP), which teaches food budgeting skills, is an excellent example.”

USDA’s Cooperative State Research, Education, and Extension Service (CSREES) funded the study through the National Research Initiative (NRI) Human Nutrition and Obesity program. CSREES’ NRI program has been the largest peer reviewed, competitive grants program at USDA. Its purpose was to support research, extension and education grants that address key problems of national, regional and multi-state importance in sustaining all components of agriculture. The 2008 Farm Bill did not renew the NRI, but did authorize the creation of the Agriculture and Food Research Initiative (AFRI). More information about AFRI can be found online.

The results of this study were published in the April 2009 issue of The American Journal of Clinical Nutrition.