Nutritional Guidelines in Canada and the US: Differences between Younger and Older Adults
The requirement for some nutrients changes as adults age. The Dietary Reference Intakes, the 2007 Canada Food Guide, and the 2005 Dietary Guidelines for Americans (MyPyramid.gov) provide guidance for the consumer and the professional for nutritional needs throughout the life span. The Guidelines provide recommendations in user-friendly messages. MyPyramid.gov and the Food Guide allow the public to access information on the internet that is individualized for age, gender, and physical activity. The Dietary Reference Intakes provide the health professional with nutrition requirements for gender and specific age groupings through the entire lifespan. This article will address those nutrients whose requirements significantly change with adult aging.
Key words: Dietary Reference Intakes, Canada Food Guide, Dietary Guidelines of America, MyPyramid, aging, nutrition.
Introduction
In 2004, the Food and Nutrition Board of the National Academies’ Institute of Medicine (IOM) completed the Dietary Reference Intakes (DRIs) for individuals throughout the life stages from birth to >70 years of age in both the United States and Canada.1-6 The IOM has given their DRI recommendations in four ways. The Estimated Average Requirement (EAR) represents the estimated median requirement for healthy individuals in a specific life stage and gender group. Recommended Dietary Allowances (RDA) which are two standard deviations above the EAR are provided when the needs of almost all (97-98%) individuals in a group is believed to be met. Adequate Intake (AI) covers the needs of all individuals in the group but data are lacking to specify with confidence the percentage of individuals covered by this intake because an EAR could not be determined. Tolerable Upper Limit (UL) is the maximum level of a daily nutrient intake that is likely to pose no risk of adverse effects. Specific numbers are given for the quantities of macro- and micronutrients that should be an average of daily intakes over the long-term.1-6
To describe the amounts and types of foods that would meet the DRIs, Health Canada released the Food Guide (FG) in 2007,7 which provides guidance in food choices, physical activity, label reading, portion sizes, and eating patterns for 16 different age and gender categories and is available in hard copy and interactively on the web at www.healthcanada.gc.ca/ foodguide. The FG also provides ten statements that are the basis for modelling the food intake pattern (Table 1).
In 2005, the Dietary Guidelines for Americans (DGA) were released by the United States Department of Health and Human Services (HHS) and the Department of Agriculture (USDA) to the general public of America two years of age and older.8 The Guidelines are the recommendations of the Dietary Guidelines Advisory Committee who used scientific evidence and expert testimony to arrive at nine key messages (Table 2). MyPyramid.gov provides the details for following the American recommendations (Figure 1). By inputting age, gender, and level of physical activity, each individual is provided the amounts of food to eat from each of the food groups. The website also has a meal tracking worksheet and allows people to assess their daily diet and physical activity.
This article will discuss the recommendations of the IOM within the context of the Canada Food Guide and the DGA as well as highlight those nutrients that have significant differing recommendations with aging.
Energy Needs
As adults age, caloric requirement decreases. The DRI for daily energy intake is based on gender specific equations using body mass index (BMI), physical activity, basal