U.S. Teens and the Nutrient Contribution and Differences of Their Selected Meal Patterns

Family Economics and Nutrition Review, Wntr, 2001 by Anna Maria Siega-Riz, Claude Cavadini, Barry M. Popkin

Adolescence is a period of great transitions. Nutrient requirements are increased from childhood because of physical growth, and behaviors acquired during this period persist into adulthood (1,11, 17,22). While many subsets of adolescents engage in behaviors that have wide public health attention, some adolescents may also follow pathways of poor food choices and reduced physical activity--both of which can also have deleterious effects on health (10,25). Among the health consequences of following these pathways have been rapid increases in obesity and adult-onset diabetes (13,23,26). Members of this age group are influenced strongly by their peers, the media, and family situation and less by their knowledge of risky behaviors (6,21,22).

Skipping meals is a common practice among adolescents: about 20 percent do not eat breakfast, and about half as many do not eat lunch (3,5,10,18,19). Skipping meals may lead to more snacking; for those who do not view skipping meals as a method of weight loss, snacks often compensate for missed calories and other key nutrients. The literature indicates that, on average, most children and adolescents average four eating occasions a day, with an upper range of 13 occasions among Mexican children who consumed as much as 45 percent of their energy from snacks (4,7,8). Research on the meal patterns of U.S. adolescents showed that most consume at least two meals (plus or minus snacks) on a consistent basis while some follow a highly inconsistent meal pattern: one meal and/or snacks all day (18).

Compared with adolescents with inconsistent meal patterns, those with consistent meal patterns consumed a diet that was adequate in calories and more nutrient dense (with respect to calcium, iron, vitamin E, and fiber) (11). Our study examines in more detail the types of food consumed by adolescents at each eating occasion and the nutrient contributions provided by each eating occasion to adolescents' total daily intakes. This study is unique: we examine snacking behaviors by using a nationally representative sample, and we determine the nutrient contributions of snacks. Previous studies have examined only the nutrient density of meals versus snacks without considering their contribution to the total diet, or previous studies have used very small samples to examine this research question (2,16).

Methods

Survey Design

Food consumption data were provided by the 1989-91 Continuing Survey of Food Intakes by Individuals (CSFII), a survey conducted by the U.S. Department of Agriculture's Agriculture Research Service. A nationally representative sample was collected by using a multistage, stratified sample design of the 48 coterminous States and Washington, DC. Data were collected in four waves during each year: one in each season, between April 1989 and May 1991. In each wave, a different sample of participants was selected. The total number of participants in all age groups sampled was 15,192.

Dietary data were collected for each individual in selected households. Using a 24-hour recall and two 1-day food records, individuals reported 3 consecutive days of intake. The female head of the household reported dietary intake for individuals less than 12 years old. We were interested in the eating patterns of adolescents, thus our analysis was restricted to 11- to 18-year-olds who reported 3 days of dietary intake (n=1,310). The classification of individuals into meal-pattern categories did not differ between 11and 12-year-olds, and the differences in nutrient composition of reported intakes of 11- and 12-year-olds were similar in magnitude to the differences between 12- and 13-year-olds. Therefore, 11-year-olds were included in the analysis despite differences in methods of data collection for dietary intake.

Variables

Meal Patterns

Survey data include descriptors of eating occasion (breakfast, lunch, dinner, supper, snack, brunch, and extended consumption) as well as the time of day each food was consumed. To identify meal patterns, we first developed clear and invariable terminology for eating occasions: Breakfast, lunch, brunch, dinner, or snack. Respondents provided the name for each meal. When respondents reported consuming either supper or dinner, the eating occasion was designated as dinner; when the respondent reported consuming both supper and dinner, dinner was designated as lunch and supper designated as dinner. This categorization was based on analysis of the data, which indicated that dinner was consumed primarily as an evening meal (85 to 87 percent between 4 and 8 p.m.). When both supper and dinner were consumed, dinner was the midday meal (56 to 69 percent between 11 a.m. and 3 p.m.) and supper was the evening meal (70 to 81 percent between 4 and 8 p.m.). Eating occasions for 1.3 percent of foods were unknown or identified as extended consumption and therefore not included in our analysis.

Three meal-pattern categories were created based on their ability to provide meaningful comparison of eating behaviors: Consistent, moderately consistent, and inconsistent. These categories are mutually exclusive and include all possible combinations of eating occasions. Respondents with a consistent meal pattern (n=538) consumed two or three meals (plus or minus snacks) on all 3 days of reported intake. Those with a moderately consistent meal pattern (n=726) consumed two or three meals (plus or minus snacks) on 2 of the 3 days of reported intake. And respondents with an inconsistent meal pattern (n=46) consumed only one meal (plus or minus snacks) or snacks only on all 3 days of reported intake.