The research by Jessica Todd, Ephraim Leibtag and Corttney Penberthy for the US Department of Agriculture (USDA) also highlighted “considerable geographic variation in the relative price of healthy foods” which the authors conclude “may contribute to geographic variation in diet and health outcomes”.
Using prices from USDA’s Quarterly Food-at-Home Price Database, the authors compared prices per 100g of the following foods:
- Packaged whole-grain products vs refined grain counterparts (whole grains were 23-60 percent more expensive)
- Dark green veg vs starchy veg/potatoes (dark green veg was 20-80 percent more expensive)
- Low-fat milk vs carbonated soft drinks (carbonated drinks were cheaper)
- Fruit juice vs non-carbonated, non-alcoholic caloric beverages/fruit drinks (still fruit drinks were cheaper)
- Orange veg (carrots, sweet potatoes) vs starchy veg (orange veg was the same price or cheaper)
- Whole fruits vs processed sweet snacks (fruit was 60-70 percent cheaper)
- Low-fat milk (skim and 1percent milk) with whole or 2 percent milk, (low-fat milk was 10-20 percent cheaper)
- Bottled water vs carbonated soft drinks (bottled water was 6-33 percent cheaper, except in New York)
They note: “The geographic variation in the relative price of the healthier option is large—ranging from 10 to 50 percent higher or lower than the price of the less healthy option - depending on the market area. These variations may have more of an effect on low-income households."
However, the price of some healthier foods had come down in relative terms, they added. “In recent years, the price of whole grains has declined relative to refined grains, which should make it easier for Americans to meet recommended intakes of whole grains.”
Marion Nestle, professor in the department of nutrition, food studies and public health at New York University, said low prices coupled with hefty marketing budgets made sugary soft drinks very appealing, even if bottled water was generally cheaper.
“People like sweet drinks and soda companies spend billions every year to convince them that their products are what people should be drinking. Few people realize the calories in sodas or how many more calories they are taking in than they need.
“I live in New York, which apparently is the one area of the country where soft drinks are cheaper than bottled water, but I’ve seen soda promotions throughout the country where sodas are priced below water.”
She added: “Low-income people are constantly complaining that fresh produce is too expensive, which indeed it is. This is a matter of national policy, which supports the price of commodity crops (corn, soybeans, sugar beets) but ignores what USDA calls ‘specialty crops’.”
If we want Americans to follow national dietary guidelines, concluded Nestle, "we have to make it easier for them to do so, and that means price incentives.”
Low-cost, nutrient-poor, energy dense foods
Adam Drewnowski, director of the Center for Obesity Research at the University of Washington, Seattle, welcomed the research: “I am glad that they started looking at the cost of healthful foods relative to less healthy ones. Of course, cost is only one factor affecting food purchases, even though it has been understudied in the US.
“There are also such things as taste, convenience, variety and health.”
Drewnowski, who has conducted his own extensive research in this field, had a paper published in the American Journal of Clinical Nutrition last year, which concluded that grains and sugary food groups were cheaper than vegetables and fruit per calorie and were cheaper than fruit per serving.
“These price differentials may help to explain why low-cost, energy-dense foods that are nutrient poor are associated with lower education and incomes.”