with many schools now offering and promoting high-calorie, low-nutrition foods throughout the school day (Fox et al., 2009). Food marketing aimed at children using multiple channels, such as digital media, has drastically increased as well (IOM, 2006). Finally, an exodus of grocery stores and an influx of fast-food restaurants in lower-income urban areas have contributed to income and racial/ethnic disparities in access to healthier foods (IOM, 2005).
Together, these environmental changes have influenced what, where, and how much Americans eat and have played a large role in the current obesity epidemic. As recommended in the Institute of Medicine (IOM) report Preventing Childhood Obesity: Health in the Balance, childhood obesity prevention should be public health in action at its broadest and most inclusive level and a national health priority (IOM, 2005). To be effective, obesity prevention efforts should use public health population-based approaches, including policy and environmental changes that affect large numbers of people. Solving the problem will require the efforts of many stakeholders, including those in the public and private sectors, working together for change.
In developing working definitions for healthy eating and healthy foods, the committee looked to the 2005 Dietary Guidelines for Americans (HHS and USDA, 2005). These guidelines, which are revised every five years and are based on the latest scientific evidence, provide information and advice for choosing a nutritious diet, maintaining a healthy weight, and achieving adequate exercise. The guidelines include 16 key recommendations that focus on food and diet (see Box 4-1). The 2005 guidelines recommend that all healthy Americans aged 2 and older consume a variety of nutrient-dense foods and beverages within and among the basic food groups and limit the intake of saturated and trans fats, cholesterol, added sugars, and alcohol. Nutrient-dense foods are foods that provide substantial amounts of vitamins, minerals, and other health-promoting components, such as fiber, for relatively few calories. Foods that are low in nutrient density supply calories but no or small amounts of vitamins, minerals, and health-promoting components (HHS and USDA, 2005). The greater the consumption of foods and beverages that are low in nutrient density and high in fats and sugars, the more difficult it is to achieve energy balance (the balance between calories consumed and calories burned through physical activity and bodily processes) and still meet nutrient needs. The lack of energy balance can lead to unhealthy weight gain. Selecting foods that are consistent with the guidelines (i.e., fruits, vegetables,