Many consumers, health professionals, and policy makers consider processed foods to be unhealthful and to contribute to an array of undesirable health conditions such as hypertension, diabetes, and obesity (IFIC, 2009). Federal dietary guidance has not ameliorated these concerns. Both the report from the 2010 Dietary Guidelines Advisory Committee (DGAC), with approximately 70 references to processed foods, and the Dietary Guidelines for Americans, with approximately 30 references to “food processing,” associate negative dietary components with processed foods (e.g., sodium, trans fatty acids, refined grains, and sugars). Yet none of the positive nutritional contributions of such foods (e.g., the alleviation of many public health concerns, their role in achieving the dietary guidelines) was cited. A published definition by Shewfelt (2009) defines processing as “any deliberate change made to a food from the time of origin to the time of consumption.” To help consumers assess the contributions of such foods, the International Food Information Council (IFIC) has described a continuum of processing levels: 1) minimally processed; 2) processed for preservation; 3) processed with a mixture of combined ingredients; 4) processed ready-to-eat foods; and 5) prepared foods/meal.
Today’s processed foods present a variety of nutritional attributes such as reduced sodium, lower saturated fat, and decreased calories. Some components of processed foods are enriched with nutrients to maintain their natural concentrations during processing, or fortified with nutrients, enhancing initial concentrations to increase nutrient density. Examples of enriched foods include products containing flour to which several B-vitamins and iron are added to prevent deficiency. Fortified foods include milk with added vitamin D to reduce risk of developing rickets and salt with iodine, which virtually eliminated goiter. Most recently, flour was fortified with folic acid to reduce the risk of neural tube defects during gestation.
Analysis of the National Health and Nutrition Examination Survey (NHANES) from 2003 through 2006, including data from approximately 17,000 participants, indicated fresh, canned, and frozen fruits and vegetables contributed 73% of vitamin C, 36% of dietary fiber, 31% of potassium, and 24% of vitamin A to the diet. Among children, fortified foods are a significant contributor to vitamin D (>50%) intake and provide 12–20% of nutrients such as vitamins A, C, B-6, and B-12. These results are similar to those reported earlier that indicated fortified foods provide significant nutrition and assisted Americans in achieving nutrient intake levels consistent with Dietary Reference Intakes (Fulgoni et al., 2011).
A more inclusive study using NHANES data (2003–2008) from more than 25,000 participants was the first to evaluate nutrient intake relative to the level of food processing based on the IFIC continuum previously noted (Eicher-Miller et al., 2012). This study presented four significant findings: 1) processed foods contribute a wide range of nutrients at all levels of processing; 2) food processing does not have a clear association with the “health” of a food; 3) the most important determinants of diet quality are the specific foods consumed, not their level of processing; and 4) consumers should not let the level of processing define their perception of the healthfulness of a food.
A similar study among children provided additional insights into the role of processed foods and nutrient intake (Eicher-Miller, manuscript submitted). Data from NHANES (2003–2008) that represented more than 10,000 participants between 2 and 18 years of age indicated all children consumed processed foods. The five processing categories noted here contribute between 66% and 84% of total daily energy and an array of important nutrients that experts recommend increasing (e.g., calcium, vitamin D, potassium, fiber), as well as components that should be reduced (e.g., saturated fat, cholesterol, total sugar, added sugars, sodium). These findings stress the importance of children and their guardians/parents making healthy choices that focus on energy and nutrient content, frequency of consumption, and serving size rather than the food processing category.
Processed foods are a well-established part of the U.S. diet and provide significant nutrient and energy contributions. Working together, the disciplines of food science and nutrition can inform processing technologies that assure food safety and maximum nutrient retention and make beneficial changes to foods to improve the health of today’s consumers and that of future generations.
Heather A. Eicher-Miller, Ph.D.,
Nutrition Science, Purdue Univ.,
West Lafayette, Ind.
Guy H. Johnson, Ph.D.,
Principal, Johnson Nutrition Solutions LLC,