It has long been claimed that nutrient-dense, energy-poor foods tend to cost more than nutrient-poor, energy-dense ones, leading those on low incomes to be more prone to obesity and other diet-related health problems.
This latest research, conducted by Adam Drewnowski of the University of Washington’s Center for Public Health Nutrition, aimed to test a wide variety of foods – a total of 1387 – comparing their cost with relative nutrient content.
The 2005 Dietary Guidelines for Americans – the guidelines currently in use, until the 2010 guidelines are published later this year – recommend that consumers should increase their consumption of nutrient-dense foods across all food groups, but the author suggests that high prices for such foods could make this goal unrealistic for some.
He told FoodNavigator-USA.com via email: “I think that we should have guidelines for all Americans and not just the elitists at Harvard. I am still waiting for those guidelines.”
Drewnowski explained that even in 1902, according to US Department of Agriculture (USDA) data, grains and sugars were cheap while fresh produce was expensive.
Using USDA nutrient composition and food prices data, along with foods reported as consumed by 2001-2002 NHANES participants, he found that the cheapest foods were vegetable oils, total fats, grains and sugars – while the highest food costs per 100g after adjusting for energy, were for protein, calcium, iron, potassium, magnesium and vitamin C.
“The present data are consistent with the earlier demonstration that grains, fats and sweets were associated with lower energy costs than were vegetables and fruit,” he wrote.
Drewnowski concluded: “The fact that healthful foods cost more than less healthy options is a formidable real-world challenge for nutrition interventions…A continuing appreciation of how food costs drive food choices is needed for a more effective food and nutrition policy.”
However, his previous research into the cost of nutrient-rich foods led him to pinpoint some affordable healthy options, including milk and milk products as the lowest-cost source of calcium; and vegetables and fruit as the lowest-cost sources of vitamin C.
But he told this publication that food cost is much more important in terms of food choices than other factors, such as education and income.
“Basically, if you don’t have money, it does not matter what else you've got,” he said.
Source: American Journal of Clinical Nutrition
First published ahead of print August 18, 2010 as doi: 10.3945/ajcn.2010.29300
“The cost of US foods as related to their nutritive value”
Author: Adam Drewnowski