Trends in food and nutrient intakes by adolescents in the United States - Research Articles
Cecilia Wilkinson EnnsAs part of the National Nutrition Monitoring and Related Research Program, each of the U.S. Department of Agriculture (USDA) food and nutrient intake surveys provides a snapshot of the food choices made at a given time by the population of the United States. Information about trends in food and nutrient intakes by adults age 20 years and over and by children age 6 to 11 years has been published (Enns, Goldman, & Cook, 1997; Enns, Mickle, & Goldman, 2002). This article focuses on trends in intakes by adolescents age 12 to 19 years.
To examine whether adolescents' food intakes have changed over time, we compared nationally representative estimates from the most recent USDA survey of dietary intakes with similar estimates from two previous USDA surveys. The three surveys were the Continuing Survey of Food Intakes by Individuals (CSFII) 1994-96, (1) CSFII 1989-91, and the Nationwide Food Consumption Survey (NFCS) 1977-78 (Tippett et al., 1995; USDA, 1983, 1999, 2000a). The estimates reported in this study are of food intakes, the percentages of individuals consuming foods, and nutrient intakes for girls and boys age 12 to 19 years during all three periods. In the discussion of diet quality in the most recent survey, we cite information on intakes stated in terms of Food Guide Pyramid servings (USDA, 2000b).
Design and Methods
The Three Surveys
The CSFII 1994-96 was the most recent source of information on adolescents' intakes in the evolving series of USDA food and nutrient intake surveys that also includes the two earlier surveys (Tippett, Enns, & Moshfegh, 2000). Differences among the three surveys in sampling and methodology are discussed briefly in the following paragraphs. More information on methods in the NFCS 1977-78 and the CSFII 1989-91 is available elsewhere (Tippett et al., 1995; USDA, 1983).
The target population covered all 50 States in 1994-96 versus the 48 conterminous States in 1977-78 and 1989-91. In 1989-91 and 1994-96, the low-income population was over-sampled. In 1977-78 and 1989-91, all adolescents in sample households were eligible for inclusion in the survey; in 1994-96, selected individuals within each household were eligible. The number of adolescents age 12 to 19 years and the all-individuals Day-1 response rate, respectively, for each survey are 5,890 and 56.9 percent (NFCS 1977-78), 1,627 and 57.6 percent (CSFII 1989-91), and 1,469 and 80.0 percent (CSFII 1994-96).
In 1977-78 and 1989-91, dietary data were collected on 3 consecutive days by using a 1-day dietary recall and a 2-day dietary record. In 1994-96, the number of days was reduced to two, partly to reduce respondent burden (Tippett & Cypel, 1998). Both days of CSFII 1994-96 dietary data were collected with 1-day dietary recalls; interviews were on nonconsecutive days, 3 to 10 days apart, to ensure that nutrient intakes on the 2 days would be statistically uncorrelated. Between the earlier surveys and the CSFII 1994-96, the 1-day recall was modified to include multiple passes through the list of all foods and beverages recalled by the respondent, with the goal of improving the completeness of the data collected (Tippett & Cypel, 1998).
The USDA Survey Nutrient Database was updated on an ongoing basis to incorporate additional nutrients and improved nutrient values as well as to reflect changes in foods on the market (Tippett & Cypel, 1998; Tippett et al., 1995; USDA, 1987, 1993).
Presentation of Estimates
Because the number of survey days and the method of data collection on Day 2 differed among the surveys, tables comparing food and nutrient intake estimates among the surveys are based on only Day-1 data collected from each individual. Using these data maximizes comparability among surveys. One-day data are appropriate for comparisons of group means. All estimates are weighted to he nationally representative.
Mean food intakes are presented "per individual," meaning intakes include those by both consumers and nonconsumers of the food group. To calculate "per user" intakes of foods, researchers may divide the mean intake of a food group by the percentage of individuals using that food group, expressed as a decimal. Because only selected food subgroups are presented, subgroup intakes will not sum to the food group total. (2) Food mixtures were not broken down; mixed foods reported by respondents were grouped by their main ingredient. (3) One effect of this method of classifying food is the inflation of some food groups or subgroups (e.g., meat mixtures) and deflation of others (e.g., sugars and sweets) relative to the amounts they would contain if all ingredients were disaggregated.
Estimates based on a small number of observations or on highly variable data may tend to be less statistically reliable than estimates based on larger sample sizes or on less variable data. Standard errors may he used to calculate a measure of the relative variability of an estimate called the coefficient of variation, the ratio of the standard error to the estimate itself. Because the CSFII has a complex sample design, sampling weights and procedures for specialized standard error estimation were used in computing the estimates and standard errors (USDA, 2000a, documentation section 5). SAS version 8.2 (1999) and SUDAAN version 7.5.1 (Shah, Barnwell, & Bieler, 1997) were used for statistical calculations.
In the tables, we flagged estimates that are potentially less reliable because of factors such as small sample sizes or large coefficients of variation. The guidelines that were used for determining when a statistic may be less reliable involve the use of a variance inflation factor in the role of a broadly calculated design effect. Those guidelines have been described in detail elsewhere (USDA, 1999, appendix B). The variance inflation factors used in this study were 1.19 (1977-78), 2.26 (1989-91), and 1.41 (1994-96).
Approximate t tests were performed to determine whether food and nutrient intakes and the percentages of individuals using foods were significantly higher or lower in 1977-78 versus 1989-91, 1989-91 versus 1994-96, and 1977-78 versus 1994-96. All told, some 460 pairs of estimates were compared. Because the analysis involved such a large number of comparisons, we used conservative criteria for significance. When significant differences are discussed in the text, they may be referred to either as "changes" (or values may be said to have risen/fallen or to be higher/lower in 1994-96 than in 1977-78) or as "trends."
The term "change" is used only if intakes (or percentages using) in 1977-78 and 1994-96 were different when p was less than 0.001. The term "trend" is used only if two criteria were met: (1) mean intakes (or percentages using) either rose or fell progressively from one survey to the next (e.g., intake X rose between 1977-78 and 1989-91, then rose again between 1989-91 and 1994-96), and (2) p was less than 0.05 for both comparisons. For each trend, the level of significance noted in the tables (< 0.05 or < 0.01) is the one that is true of both the 1977-78 versus 1989-91 t test and the 1989-91 versus 1994-96 t test. For example, if the 1977-78 versus 1989-91 t test was significant at p < 0.01 but the 1989-91 versus 1994-96 t test was significant at p < 0.05, the latter level is shown in the table.
Results and Discussion
Beverages
Since the late 1970s, the overall picture of beverage intakes by adolescents has changed considerably. The diets of both girls and boys age 12 to 19 had decreasing trends over time in both intakes of total fluid milk and the percentages of individuals using fluid milk (tables 1-4). Both girls' and boys' diets had increasing trends in intakes of soft drinks, and boys' diets also had a trend to a higher percentage of individuals using soft drinks. In 1977-78 adolescents drank at least one and one-half times as much fluid milk as any other beverage, but by 1994-96 they drank about twice as much soft drinks as milk. Adolescents' intake of noncitrus juices and nectars--such as apple juice, grape juice, and 100-percent fruit juice blends--tripled between 1977-78 and 1994-96, although in the latter survey, they still drank less noncitrus juices than soft drinks, milk, or fruit drinks and ades. Adolescents' intakes of fruit drinks and ades, which contain little or no fruit juice, doubled between 1977-78 and 1994-96.
The shift in beverage intakes is of nutritional concern. Guenther (1986) found negative associations between intake of soft drinks and intakes of milk, calcium, magnesium, riboflavin, vitamin A, and vitamin C. Harnack, Stang, and Story (1999), in an analysis of CSFII 1994 data, reported a positive association between consumption of nondiet soft drinks and energy intake. Wyshak (2000) found that high-school-age girls who drink carbonated beverages may have a higher risk of bone fractures than is the case for girls who do not drink carbonated beverages. In a 19-month-long prospective study, Ludwig, Peterson, and Gortmaker (2001) observed an association between consumption of sugar-sweetened drinks and childhood obesity. Because the studies by Guenther (1986), Harnack et al. (1999), Wyshak (2000), and Ludwig et al. (2001) were observational, it cannot be inferred that the relationships between soft drinks and the negative outcomes described were causal. Further research is needed in this area.
Foods
Overall, the intakes of grain products were about two-fifths higher in 1994-96 than in 1977-78 for girls and boys age 12 to 19 years (tables 1 and 2). In all three surveys, the subgroup "mixtures mainly grain"--grain-based mixtures such as pasta with sauce, rice dishes, and pizza--accounted for the largest share (by weight) of grain products eaten by adolescents. Teenage girls' and boys' diets had increasing trends for both intakes and percentages using grain mixtures (tables 3 and 4).
Increasing trends were observed in adolescents' intakes of grain-based snack foods from the group "crackers, popcorn, pretzels, and corn chips." Among boys, there were also trends toward lower intakes and percentages consuming yeast breads and rolls; the decline in girls' intakes and percentages using yeast breads and rolls could not be classified as a trend. Yeast breads and rolls are common components in sandwiches, and some sandwiches (especially fast-food items) are categorized under "mixtures mainly meat, poultry, fish." Intake estimates for yeast breads and rolls would be higher if the breads and rolls from those sandwiches were included here.
In 1994-96 only 35 percent of girls and 48 percent of boys consumed the number of servings of grain products recommended in the Food Guide Pyramid based on their caloric intake (USDA, 2000b). Despite Pyramid recommendations to choose "several servings a day" of whole-grain foods (USDA, 1996), adolescents' intake of whole grains in 1994-96 was only about 1 serving per day.
Few trends were observed in adolescents' intakes of vegetables. It is important to remember that vegetables are frequently consumed as part of meat mixtures and grain mixtures. For adults in 1994, intakes of vegetables accounted for about 24 percent and 28 percent (by weight) of grain mixtures and meat mixtures, respectively (Enns et al., 1997). If vegetables account for a similar proportion of grain and meat mixtures for adolescents as for adults, then the observed higher intakes of grain mixtures would at least partially offset the lower intakes of vegetables. Further research is needed to clarify this issue. However, even when mixture ingredients are separated into their respective groups, 74 percent of adolescent girls and 67 percent of adolescent boys had diets that did not meet the Pyramid recommendations for servings of vegetables (USDA, 2000b). Despite Pyramid recommendations to eat both dark-green leafy vegetables and legumes "several times a week," adolescents ate no more than one-fifth of a serving from either category on any given day.
Adolescents' intakes of fried white potatoes were higher in 1994-96 than in 1977-78. The percentages of adolescents using tomatoes rose between 1977-78 and 1994-96, and the increase qualified as a trend among boys. Both girls and boys had lower intakes and lower percentages using the subgroups "green beans" and "corn, green peas, and lima beans" in 1994-96 than in 1977-78. The decrease in the percentage of boys using corn, green peas, and lima beans met the definition of a trend.
Aside from the observed changes in intakes of noncitrus juices and nectars, few changes occurred in fruit consumption. Between 1977-78 and 1994-96, the percentage using citrus juices and apples fell among girls and both intakes and percentages using apples fell among boys. In 1994-96 only 18 percent of girls and 14 percent of boys consumed the number of servings of fruit recommended in the Food Guide Pyramid based on their caloric intake (USDA, 2000b).
Among milk and milk products subgroups, adolescents' intakes of some high-fat items (e.g., whole milk) decreased and others (e.g., cheese) increased. Notably, milk intakes shifted away from whole milk. (4) Decreasing trends were seen both in adolescents' intakes of whole milk and in the percentages of adolescents using whole milk. Intakes of lower fat milks (2%, 1%, and skim) by adolescents surpassed those of whole milk in 1989-91. Although the percentages of adolescents drinking skim milk more than doubled between 1977-78 and 1994-96, they still remained low (7 to 9 percent), as did their intakes of skim milk (30 to 40 grams [g], or about 1 to 1-1/3 fluid ounces). None of the shifts in intakes of lower fat milks or percentages using them qualified as a trend.
On the other hand, increasing trends in the percentages of adolescents using cheese were seen. Although cheese intakes were higher in 1994-96 than in 1977-78, the increase did not qualify as a trend. Because cheese is a common component in both grain and meat mixtures, estimates for cheese would be even higher if the cheese that was an ingredient in these mixtures were included here. In 1994-96 only 12 percent of girls and 30 percent of boys consumed the number of servings of dairy products recommended in the Food Guide Pyramid based on their age (USDA, 2000b).
The percentages of both girls and boys using foods from the meat, poultry, and fish group were lower in 1994-96 than in 1977-78. Both intakes and percentages of individuals using beef and pork separately (i.e., not as part of a mixture) fell. In all three surveys, intakes of "mixtures mainly meat, poultry, fish"--such as beef stew, hamburgers, chicken pot pie, and tuna salad--accounted for the largest share of intakes of total meat, poultry, and fish. Percentages of adolescents consuming eggs were lower in 1994-96 than in 1977-78.
In 1994-96 only 22 percent of girls and 44 percent of boys consumed the number of servings of meat and meat alternates recommended in the Food Guide Pyramid based on their caloric needs (USDA, 2000b). Cooked dry beans (other than soybeans) and peas, which may be tabulated under either the vegetable group or the meat group, were tabulated under the meat group for that analysis; otherwise, the percentages consuming the recommended number of servings from the meat group would have been even lower.
For both girls and boys, intakes and percentages using candy increased between 1977-78 and 1994-96. However, the increases qualified as trends only for the adolescent boys. Fats, oils, and sugars are common ingredients in foods; thus, the estimates of intakes and percentages using fats, oils, and sugars would be higher if the amounts that were ingredients in other foods were included here.
In 1994-96, intakes of discretionary fat and added sugars (5)--items from the tip of the Pyramid--were much higher than recommended (USDA, 2000b). Among adolescents, discretionary fat intake accounted for about 25 percent of calories for girls and 26 percent for boys. In a diet that meets all other Pyramid recommendations, discretionary fat intake would be expected to be closer to 15 percent of calories (USDA, 1996). In 1994-96, adolescent girls consumed 23 teaspoons of added sugars per day in a diet providing around 1,800 calories; adolescent boys consumed 34 teaspoons of added sugars per day in a diet providing around 2,700 calories. The Pyramid suggests that Americans try to limit their added sugars to 6 teaspoons a day if they eat about 1,600 calories, 12 teaspoons at 2,200 calories, or 18 teaspoons at 2,800 calories (USDA, 1996).
Energy Out of Balance
Over roughly the same period covered by the present analysis, the percentages of 12- to 19-year-old boys in the United States who were overweight (6) rose from 4.5 percent in 1976-80 to 11.3 percent in 1988-94; among adolescent girls, the increase was from 5.4 to 9.7 percent (U.S. Department of Health and Human Services [DHHS], 2001). The increasing prevalence of overweight is of concern for many reasons, including the increasing incidence and prevalence of Type II diabetes mellitus among overweight and obese adolescents (American Diabetes Association, 2000). Overweight in adolescence is also associated with high blood lipids, hypertension, an increased likelihood of overweight in adulthood, and various other problems (DHHS, 2001).
In the face of increasing overweight, one would expect to see either increasing energy intake or decreasing energy expenditure or both. In the present analysis, no significant trends or changes were seen in energy intakes between 1977-78 and 1994-96 (table 5). Adolescent boys' energy intake was over 200 kcal higher in 1994-96 than in 1977-78 (2,766 kcal vs. 2,523 kcal). Girls' energy intake was 1,910 kcal in 1994-96 and 1,797 kcal in 1977-78, but no significant difference was found.
Findings of underreporting in surveys, which are often but not always higher among overweight respondents, might lead one to speculate that the lack of a trend in energy intake could be due to increased underreporting over time as a function of increased obesity. On the other hand, methodological improvements in the Agricultural Research Service's 24-hour recall have addressed several issues that are considered important in obtaining complete intake data (see "Design and Methods").
Using CSFII data, Krebs-Smith et al. (2000) identified low-energy reporters by first estimating basal metabolic rate (BMR)7 based on self-reported body weight, gender, and age and then comparing the BMR estimates with a cutoff level. (9) They found that the percentage of adults who were low-energy reporters was lower in 1994-96 (15 percent) than in 1989-91 (25 percent).
They also found less underreporting among adolescents than among adults. Only 9.5 percent of adolescents age 12 to 19 in 1994-96 were found to be low-energy reporters (S.M. Krebs-Smith, personal communication, March 8, 2002). Livingstone and Robson (2000) have stated that determining whether an adolescent's energy intake is implausibly low should take into account detailed information on the adolescent's activity level; however, such information is not available from the three surveys in the present analysis.
Inactivity is probably a strong factor in the increased prevalence of overweight in the United States (DHHS, 2001; Weinsier, Hunter, Heini, Goran, & Sell, 1998). In 1996 the Surgeon General concluded that nearly half of American youths 12 through 21 years of age are not vigorously active on a regular basis, that about one-tenth of them are not active at all, and that physical activity declines during adolescence (DHHS, 1996).
The Dietary Guidelines for Americans recommend that adolescents engage in at least 60 minutes of moderate physical activity on most days of the week, preferably daily (USDA & DHHS, 2000). One strategy suggested by the Dietary Guidelines to help teens increase their activity is to limit television watching. On any given day in 1994-96, 32 percent of girls and 34 percent of boys age 12 to 19 watched 4 or more hours of television or videos, 29 percent of girls and 34 percent of boys watched 2 to 3 hours, and 39 percent of girls and 33 percent of boys watched 1 hour or less (unpublished data).
Energy-Providing Nutrients (Macronutrients)
Trends toward higher carbohydrate intakes were evident among both adolescent girls and boys. For girls, carbohydrate intake was about 60 g per day higher in 1994-96 than in 1977-78; for boys, the intake was 87 g higher. For both girls and boys, protein and fat intakes were lower in 1994-96 than in 1977-78, although the p value criterion for a trend was not met.
These shifts in adolescents' macronutrient intakes between 1977-78 and 1994-96 were reflected in trends toward a lower proportion of food-energy intake from fat and a higher proportion from carbohydrate. Adolescents' percentage of calories from protein was also lower in 1994-96 than in 1977-78, but the trend definition was not met. The proportion of energy from fat in adolescents' diets in 1994-96 (33 percent for girls and 32 percent for boys) was still higher than what is recommended by the Dietary Guidelines for Americans: 30 percent of calories or less (USDA & DHHS, 2000). At 11 percent of calories for girls and 12 percent of calories for boys (unpublished data), saturated fat intakes still exceeded the recommendation of less than 10 percent of calories.
Although the shifts in the proportion of energy intake from fat and carbohydrate appear to have brought the macronutrient proportions in the average diet nearer to the recommended levels, a closer examination is less encouraging. The observed decrease in the percentage of calories from fat is more due to the increase in calories from carbohydrate than to the decrease in fat intake. Fat intake decreased by almost 100 kcal for both girls and boys, but carbohydrate intake increased by about 240 kcal for girls and almost 350 kcal for boys, based on estimates in table 5 that were multiplied by Merrill and Watt's (1973) general conversion factors of 9 kcal/g for fat and 4 kcal/g for carbohydrate.
Vitamins, Minerals, and Other Dietary Components
Increasing trends were observed in iron intakes for both adolescent girls and boys (table 5). Boys' diets had an increasing trend in niacin intake, and girls' diets had a higher intake that did not meet the trend criteria. Additionally, thiamin and vitamin B6 intakes for adolescents were higher, and vitamin [B.sub.12] intakes were lower.
Mean dietary fiber intakes in 1994-96 were 13 g for girls and 17 g for boys (unpublished data). The Institute of Medicine (2002) has set the adequate intake of total fiber (which equals dietary fiber plus a minor amount of functional fibers) at 26 g/day for girls 9 to 18 years, 31 g/day for boys 9 to 13 years, and 38 g/day for boys 14 to 18 years. Observed increases in carbohydrate intakes were paralleled neither by significant increases in dietary fiber intakes nor by increases in overall intakes of fiber-rich foods.
Summary and Recommendations
The pattern of results seen for adolescents echos many of the findings for adults and children (Enns, Goldman, & Cook, 1997; Enns, Mickle, & Goldman, 2002). Adolescents' food intakes changed in various ways during the last quarter of the 20th century. Adolescents' diets exhibited trends not only toward large increases in intakes of soft drinks but also toward decreases in intakes of total fluid milk that were driven by decreases in whole milk. Some other shifts were to higher intakes of grain products (especially grain mixtures), crackers/popcorn/pretzels/corn chips, fried potatoes, noncitrus juices/nectars, lowfat milk, skim milk, cheese, candy, and fruit drinks/ades. Other shifts were to lower intakes of yeast breads/rolls, green beans, corn/green peas/lima beans, beef, and pork.
Despite those shifts in intakes, most of the take-home messages about how to improve adolescents' diets remain the same:
* Eat more whole grains.
* Eat more vegetables, especially dark-green and deep-yellow vegetables.
* Eat more fruits--both citrus and noncitrus, with an emphasis on whole fruits rather than juices.
* Eat more legumes.
* Shift to lean meats and meat alternates.
* Drink more skim or 1% milk, or eat more lowfat dairy products, or include plenty of nondairy sources of calcium.
* Decrease the amount of fat used in cooking.
The amount of discretionary fat and added sugars in adolescents' diets is much higher than is recommended by the Food Guide Pyramid. Adolescents' diets would benefit overall from lowering intakes of "empty-calorie" foods and beverages that are high in fats and sugars but provide few other nutrients. In addition, when choosing among more nutrient-dense foods, adolescents would do well to shift toward items lower in fat and sugar.
Increases in intakes of foods high in fiber and complex carbohydrate--such as whole grains, vegetables, fruits other than fruit juices, and legumes--could lead to a diet lower in fat and added sugars and higher in fiber and complex carbohydrate. If such a change led to a lower overall energy intake, weight maintenance or loss would be made easier. Because widespread inactivity has been identified as a factor in the national epidemic of overweight, increased activity should be encouraged. In a recent Call to Action, the Surgeon General outlined key actions to address overweight and obesity (DHHS, 2001).
Educational efforts and interventions successfully change dietary behavior among adolescents, and factors leading to the effectiveness of nutrition education have been identified ("Adolescent Nutrition," 2002; Contento et al., 1995). Resources must be committed on every level--national, State, local, community, school, and family, as well as in the health care system--to help adolescents eat more healthfully and become more active.
Table 1. Trends and changes in adolescent (1) girls' mean intakes from selected food groups Intake (grams) Food group 1977-78 1989-91 1994-96 Grain products 215 261 306 Yeast breads and rolls 52 45 40 Ready-to-eat cereals 11 15 17 Cakes, cookies, pastries, pies 34 26 37 Crackers, popcorn, pretzels, corn chips 5 8 15 Mixtures mainly grain 59 100 132 Vegetables 165 129 145 White potatoes 61 56 61 Fried white potatoes 18 31 31 Dark-green vegetables 6 5 9 Deep-yellow vegetables 6 5 (4) 4 Tomatoes 16 17 18 Green beans 8 5 4 Corn, green peas, lima beans 19 12 8 Fruits 129 133 157 Citrus juices 53 68 67 Apples 20 11 13 Melons and berries 7 7 15 Noncitrus juices and nectars 12 19 35 Milk and milk products 380 308 268 Fluid milk 303 239 189 Whole milk 166 97 67 Lowfat milk 53 115 91 Skim milk 13 16 (3) 30 Milk desserts 25 20 29 Cheese 9 15 14 Meat, poultry, and fish 186 152 158 Beef 46 19 21 Pork 16 11 5 Frankfurters, sausages, luncheon meats 17 15 15 Chicken 21 20 19 Fish and shellfish 10 6 6 Mixtures mainly meat, poultry, fish 66 73 85 Eggs 18 12 13 Legumes 19 13 14 Fats and oils 11 10 10 Sugars and sweets 22 23 31 Candy 5 6 12 Beverages 417 534 645 Tea 89 87 92 Fruit drinks and ades 72 87 134 Carbonated soft drinks 208 324 396 Food group Change (2) Trend (3) Grain products +91 ** Yeast breads and rolls -12 Ready-to-eat cereals +6 Cakes, cookies, pastries, pies Crackers, popcorn, pretzels, corn chips +11 * Mixtures mainly grain +73 * Vegetables White potatoes Fried white potatoes +13 Dark-green vegetables Deep-yellow vegetables Tomatoes Green beans -5 Corn, green peas, lima beans -11 Fruits Citrus juices Apples Melons and berries Noncitrus juices and nectars +23 Milk and milk products -112 Fluid milk -114 * Whole milk -99 * Lowfat milk +38 Skim milk +17 Milk desserts Cheese +5 Meat, poultry, and fish -28 Beef -25 Pork -10 Frankfurters, sausages, luncheon meats Chicken Fish and shellfish Mixtures mainly meat, poultry, fish Eggs Legumes Fats and oils Sugars and sweets Candy +7 Beverages +228 ** Tea Fruit drinks and ades +62 Carbonated soft drinks +188 * (1) 12 to 19 years. (2) Change = mean intakes in 1977-78 and 1994-96 are significantly different at p < 0.001. (3) Trend = mean intake rose or fell progressively from 1977-78 through 1989-91 to 1994-96. (4) Estimate is based on small sample size or coefficient of variation [greater than or equal to] 30 percent. * = trend significant at p < 0.05. * = trend significant at p < 0.01. Table 2. Trends and changes in adolescent (1) boys' mean intakes from selected food groups Intake (grams) Food group 1977-78 1989-91 1994-96 Grain products 297 351 406 Yeast breads and rolls 77 65 54 Ready-to-eat cereals 18 25 29 Cakes, cookies, pastries, pies 48 45 49 Crackers, popcorn, pretzels, corn chips 6 9 19 Mixtures mainly grain 78 121 175 Vegetables 209 173 176 White potatoes 86 78 86 Fried white potatoes 27 35 44 Dark-green vegetables 8 9 6 Deep-yellow vegetables 8 4 6 Tomatoes 17 22 28 Green beans 12 6 (4) 3 (4) Corn, green peas, lima beans 27 20 10 Fruits 143 157 174 Citrus juices 60 84 94 Apples 24 20 13 Melons and berries 7 6 (4) 11 (4) Noncitrus juices and nectars 9 12 29 Milk and milk products 571 461 409 Fluid milk 472 376 303 Whole milk 257 145 100 Lowfat milk 88 197 157 Skim milk 17 22 (4) 40 Milk desserts 34 32 29 Cheese 11 13 19 Meat, poultry, and fish 257 221 250 Beef 64 34 30 Pork 24 12 12 Frankfurters, sausages, luncheon meats 26 27 28 Chicken 26 26 26 Fish and shellfish 9 7 8 Mixtures mainly meat, poultry, fish 94 103 135 Eggs 28 16 22 Legumes 28 27 17 Fats and oils 13 14 12 Sugars and sweets 32 29 35 Candy 5 8 13 Beverages 467 639 994 Tea 98 95 115 Fruit drinks and ades 98 104 205 Carbonated soft drinks 220 424 608 Food group Change (2) Trend (3) Grain products +109 * Yeast breads and rolls -23 * Ready-to-eat cereals +10 Cakes, cookies, pastries, pies Crackers, popcorn, pretzels, corn chips +14 * Mixtures mainly grain +96 ** Vegetables White potatoes Fried white potatoes +17 Dark-green vegetables Deep-yellow vegetables Tomatoes +11 Green beans -9 Corn, green peas, lima beans -17 Fruits Citrus juices Apples -11 Melons and berries Noncitrus juices and nectars +20 Milk and milk products -162 Fluid milk -169 * Whole milk -157 * Lowfat milk +69 Skim milk Milk desserts Cheese +8 Meat, poultry, and fish Beef -34 Pork -12 Frankfurters, sausages, luncheon meats Chicken Fish and shellfish Mixtures mainly meat, poultry, fish +41 Eggs Legumes Fats and oils Sugars and sweets Candy +8 * Beverages +527 ** Tea Fruit drinks and ades +107 Carbonated soft drinks +388 ** (1) 12 to 19 years. (2) Change = mean intakes in 1977-78 and 1994-96 are significantly different at p < 0.001. (3) Trend = mean intake rose or fell progressively from 1977-78 through 1989-91 to 1994-96. (4) Estimate is based on small sample size or coefficient of variation [greater than or equal to] 30 percent. * = trend significant at p < 0.05. ** =trend significant at p < 0.01. Table 3. Trends and changes in percentages of adolescent (1) girls using items from selected food groups Percentage using Food group 1977-78 1989-91 1994-96 Grain products 96 97 98 (4) Yeast breads and rolls 75 65 61 Ready-to-eat cereals 29 28 30 Cakes, cookies, pastries, pies 40 30 41 Crackers, popcorn, pretzels, corn chips 16 20 31 Mixtures mainly grain 23 39 46 Vegetables 83 72 79 White potatoes 51 45 46 Fried white potatoes 28 32 35 Dark-green vegetables 5 6 7 Deep-yellow vegetables 7 7 11 Tomatoes 22 29 35 Green beans 10 7 4 Corn, green peas, lima beans 18 12 7 Fruits 50 44 46 Citrus juices 25 21 18 Apples 13 7 8 Melons and berries 3 3 6 Noncitrus juices and nectars 4 7 10 Milk and milk products 84 77 75 Fluid milk 72 60 50 Whole milk 42 29 18 Lowfat milk 13 27 24 Skim milk 4 4 9 Milk desserts 18 14 17 Cheese 19 29 36 Meat, poultry, and fish 92 81 80 Beef 33 18 22 Pork 21 14 11 Frankfurters, sausages, luncheon meats 27 27 25 Chicken 17 17 19 Fish and shellfish 9 6 6 Mixtures mainly meat, poultry, fish 32 35 34 Eggs 23 13 15 Legumes 11 9 11 Fats and oils 53 48 46 Sugars and sweets 47 44 46 Candy 9 12 24 Beverages 73 78 87 Tea 21 18 19 Fruit drinks and ades 19 21 27 Carbonated soft drinks 46 58 62 Food group Change (2) Trend (3) Grain products Yeast breads and rolls -15 Ready-to-eat cereals Cakes, cookies, pastries, pies Crackers, popcorn, pretzels, corn chips +15 Mixtures mainly grain +23 * Vegetables White potatoes Fried white potatoes Dark-green vegetables Deep-yellow vegetables Tomatoes +13 Green beans -6 Corn, green peas, lima beans -11 Fruits Citrus juices -7 Apples -5 Melons and berries Noncitrus juices and nectars +6 Milk and milk products -9 Fluid milk -22 ** Whole milk -24 ** Lowfat milk +11 Skim milk +6 Milk desserts Cheese +17 * Meat, poultry, and fish -12 Beef -11 Pork -10 Frankfurters, sausages, luncheon meats Chicken Fish and shellfish Mixtures mainly meat, poultry, fish Eggs -8 Legumes Fats and oils Sugars and sweets Candy +15 Beverages +14 Tea Fruit drinks and ades Carbonated soft drinks +17 (1) 12 to 19 years. (2) Change = percentages in 1977-78 and 1994-96 are significantly different at p < 0.001. (3) Trend = percentage rose or fell progressively from 1977-78 through 1989-91 to 1994-96. (4) Estimate is based on small sample size or coefficient of variation [greater than or equal to] 30 percent. * = trend significant at p < 0.05. ** = trend significant at p < 0.01. Table 4. Trends and changes in percentages of adolescent (1) boys using items from selected food groups Percentage using Change Trend Food group 1977-78 1989-91 1994-96 (2) (3) Grain products 98 97 98 (4) Yeast breads and rolls 81 71 63 -19 * Ready-to-eat cereals 37 35 33 Cakes, cookies, pastries, pies 45 39 41 Crackers, popcorn, pretzels, corn chips 15 20 27 +12 Mixtures mainly grain 25 37 46 +21 * Vegetables 87 81 78 -9 White potatoes 58 50 50 -9 Fried white potatoes 34 37 39 Dark-green vegetables 6 6 4 Deep-yellow vegetables 8 8 8 Tomatoes 23 32 43 +20 ** Green beans 12 6 3 -9 Corn, green peas, lima beans 23 14 7 -15 ** Fruits 50 44 45 Citrus juices 26 24 22 Apples 13 10 8 -5 Melons and berries 3 3 4 Noncitrus juices and nectars 3 4 8 +5 Milk and milk products 90 87 81 -9 Fluid milk 82 72 60 -22 ** Whole milk 50 31 23 -27 ** Lowfat milk 16 39 31 +15 Skim milk 3 5 7 +4 Milk desserts 20 16 14 -7 Cheese 19 27 37 +18 ** Meat, poultry, and fish 96 90 87 -9 Beef 37 26 24 -13 Pork 27 14 16 -11 Frankfurters, sau- sages, luncheon meats 32 35 32 Chicken 16 18 18 Fish and shellfish 7 5 5 Mixtures mainly meat, poultry, fish 37 36 38 Eggs 28 15 17 -11 Legumes 12 11 11 Fats and oils 54 52 43 +11 Sugars and sweets 53 41 47 Candy 8 14 21 +13 ** Beverages 72 78 87 +16 Tea 21 14 16 Fruit drinks and ades 20 18 28 +8 Carbonated soft drinks 43 59 69 +26 * (1) 12 to 19 years. (2) Change = percentages in 1977-78 and 1994-96 are significantly different at p < 0.001. (3) Trend = percentage rose or fell progressively from 1977-78 through 1989-91 to 1994-96. (4) Estimate is based on small sample size or coefficient of variation [greater than or eqaul to] 30 percent. * = trend significant at p < 0.05. ** = trend significant at p < 0.01. Table 5. Trends and changes in adolescent (1) girls' and boys' mean intakes of food energy and selected nutrients and mean percentages of calories from protein, fat, and carbohydrate Intake Change Trend 1977-78 1989-91 1994-96 (2) (3) Girls Food group n=2,993 n=837 n=732 Energy (kcal) 1,797 1,748 1,910 Protein (g) 70.6 66.0 65.3 -5.3 Fat (g) 80.0 67.4 69.3 -10.7 Carbohydrate (g) 202.0 223.5 261.9 +59.9 ** Protein (% kcal) 16.0 15.4 14.0 -2.0 Fat (% kcal) 39.3 33.8 32.2 -7.2 * Carbohydrate (% kcal) 45.4 51.7 55.0 +9.6 ** Vitamin A (IU) 4,410 4,554 4,817 Vitamin C (mg) 78 90 95 Thiamin (mg) 1.23 1.39 1.44 +0.21 Riboflavin (mg) 1.72 1.72 1.75 Niacin (mg) 16.7 18.1 19.0 +2.3 Vitamin [B.sub.6] (mg) 1.37 1.42 1.53 +0.16 Vitamin [B.sub.12] ([micro]g) 5.34 3.66 3.8 -1.54 Calcium (mg) 784 797 771 Phosphorus (mg) 1,127 1,123 1,108 Magnesium (mg) 213 216 223 Iron (mg) 10.3 11.9 13.8 +3.5 ** Boys n=2,897 n=790 n=737 Energy (kcal) 2,523 2,459 2,766 +243 Protein (g) 99.8 93.1 97.5 Fat (g) 113.7 96.8 102.8 -10.8 Carbohydrate (g) 279.0 310.9 366.1 +87.0 ** Protein (% kcal) 16.1 15.6 14.4 -1.7 Fat (% kcal) 39.9 34.7 33.1 -6.8 ** Carbohydrate (% kcal) 44.6 50.8 53.2 +8.5 ** Vitamin A (IU) 6,018 5,893 6,361 Vitamin C (mg) 97 114 119 Thiamin (mg) 1.76 1.99 2.13 +0.36 Riboflavin (mg) 2.51 2.49 2.58 Niacin (mg) 23.3 25.0 27.8 +4.4 * Vitamin [B.sub.6] (mg) 1.92 2.01 2.21 +0.29 Vitamin [B.sub.12] ([micro]g) 7.50 5.89 5.85 -1.65 Calcium (mg) 1,145 1,145 1,145 Phosphorus (mg) 1,608 1,598 1,633 Magnesium (mg) 301 299 311 Iron (mg) 14.5 17.8 19.8 +5.3 * (1) 12 to 19 years. (2) Change = mean intakes (or percentages) in 1977-78 and 1994-96 are significantly different at p < 0.001. (3) Trend = mean intake (or percentage) rose or fell progressively from 1977-78 through 1989-91 to 1994-96. * = trend significant at p < 0.05. ** = trend significant at p < 0.01.
(1) Although the most recent USDA dietary intake survey encompassed the year 1998 as well as 1994-96, data collection in 1998 only included children under 10 years of age. For that reason, we identify the survey in this article as the CSFII 1994-96. The sampling weights constructed for analysis of the CSFII 1994-96 data were used for the present analysis.
(2) Readers interested in subgroups not included here are directed to Tippett et al. (1995) and USDA (1983, 1999).
(3) See "Table Notes" in Tippett et al. (1995) and USDA (1983); see "Descriptions of Food Groups" in USDA (1999).
(4) Another shift occurred that can be seen by summing the milk subgroup intakes (whole, lowfat, and skim) in a given survey and dividing by the intake of total fluid milk. A greater proportion of total fluid milk was allocated to a specific fat level in later years than in 1977-78. The increase may indicate a greater awareness of the fat level of milk, because the ability to classify fluid milk as whole, lowfat, or skim depends on information provided by respondents. Milk whose fat level was not specified was included under total fluid milk but not in any of the subgroups.
(5) For definitions of discretionary fat and added sugars, see appendix D in Pyramid Servings table set 1 (USDA, 2000b).
(6) Overweight is defined as body mass index (BMI) at or above the sex- and age-specific 95th percentile BMI cutoff points reported in the revised CDC Growth Charts: United States (Kuczmarski et al., 2000).
(7) BMR was estimated by using the formula developed by Schofield (1985).
(8) Eighty percent of BMR was the cutoff level used. That level was proposed by Goldberg et al. (1991) as the lower limit of plausible energy intake for a single individual with 2 days of intake data and 99.7 percent confidence limits.
References
Adolescent nutrition: A springboard for health [Supplement]. (2002). Journal of the American Dietetic Association, 102(3).
American Diabetes Association. (2000). Type 2 diabetes in children and adolescents. Diabetes Care, 23(3), 381-389.
Contento, I., Balch, G.I., Bronner, Y.L., Lytle, L.A., Maloney, S.K., Olson, C.M., et al. (1995). The effectiveness of nutrition education and implications for nutrition education policy, programs, and research: A review of research. Journal of Nutrition Education, 27(6); special issue.
Enns, C.W., Goldman, J.D., & Cook, A. (1997). Trends in food and nutrient intakes by adults: NFCS 1977-78, CSFII 1989-91, and CSFII 1994-95. Family Economics and Nutrition Review, 10(4), 2-15.
Enns, C.W., Mickle, S.J., & Goldman, J.D. (2002). Trends in food and nutrient intakes by children in the United States. Family Economics and Nutrition Review, 14(2), 56-68.
Guenther, P.M. (1986). Beverages in the diets of American teenagers. Journal of the American Dietetic Association, 86(4), 493-499.
Goldberg, G.R., Black, A.E., Jebb, S.A., Cole, T.J., Murgatroyd, P.R., Coward, W.A., et al. (1991). Critical evaluation of energy intake data using fundamental principles of energy physiology: 1. Derivation of cut-off limits to identify under-recording. European Journal of Clinical Nutrition 45, 569-581.
Harnack, L., Stang, J., & Story, M. (1999). Soft drink consumption among US children and adolescents: Nutritional consequences. Journal of the American Dietetic Association, 99(4), 436-441.
Institute of Medicine. (2002). Dietary Reference Intakes for Energy, Carbohydrate, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. Washington, DC: National Academic Press.
Krebs-Smith, S.M., Graubard, B.I., Kahle, L.L., Subar, A.F., Cleveland, L.E., & Ballard-Barbash, R. (2000). Low energy reporters vs others: A comparison of reported food intakes. European Journal of Clinical Nutrition, 54(4), 281-287.
Kuczmarski, R.J., Ogden, C.L., Grummer-Strawn, L.M., Flegal, K.M., Guo, S.S., Wei, R., et al. (2000). CDC Growth Charts: United States (Advance Data from Vital and Health Statistics, No. 314). Hyattsville, MD: National Center for Health Statistics. Retrieved May 21, 2002, from http://www.cdc.gov/nchs/data/ad/ ad314.pdf.
Livingstone, M.B.E., & Robson, P.J. (2000). Measurement of dietary intake in children. Proceedings of the Nutrition Society, 59(2), 279-293.
Ludwig, D.S., Peterson, K.E., & Gortmaker, S.L. (2001). Relation between consumption of sugar-sweetened drinks and childhood obesity: A prospective, observational analysis. Lancet, 357, 505-508.
Merrill, A.L., & Watt, B.K. (1973). Energy Value of Foods--Basis and Derivation. U.S. Department of Agriculture, Agriculture Handbook No. 74, sl. rev.
SAS (Version 8.2) [computer software]. (1999). Cary, NC: SAS Institute.
Schofield, W.N. (1985). Predicting basal metabolic rate, new standards and review of previous work. Human Nutrition Clinical Nutrition, 39C(Suppl. 1), 5-41.
Shah, B.V., Barnwell, B.G., & Bieler, G.S. (1997). SUDAAN (Version 7.5.1) [computer program]. Research Triangle Park, NC: Research Triangle Institute.
Tippett, K.S., & Cypel, Y.S. (Eds.). (1998). Design and Operation: The Continuing Survey of Food Intakes by Individuals and the Diet and Health Knowledge Survey 1994-96. U.S. Department of Agriculture, Agricultural Research Service, Nationwide Food Surveys Rep. No. 96-1; NTIS No. PB98-137268. Retrieved May 21, 2002, from http://www.barc.usda.gov/bhnrc/ foodsurvey/Dor.html.
Tippett, K.S., Enns, C.W., & Moshfegh, A.J. (2000). Food consumption surveys in the U.S. Department of Agriculture. In F.J. Francis (Ed.), Encyclopedia of Food Science and Technology (2nd. ed., pp. 889-897). New York: Wiley.
Tippett, K.S., Mickle, S.J., Goldman, J.D., Sykes, K.E., Cook, D.A., Sebastian, R.S., et al. (1995). Food and Nutrient Intakes by Individuals in the United States, 1 Day, 1989-91. U.S. Department of Agriculture, Agricultural Research Service, Continuing Survey of Food Intakes by Individuals 1989-91, Nationwide Food Surveys Rep. No. 91-2; NTIS No. PB95-272746.
U.S. Department of Agriculture. (1983). Food Intakes: Individuals" in 48 States, Year 1977-78. U.S. Department of Agriculture, Human Nutrition Information Service, Nationwide Food Consumption Survey 1977-78, Rep. I-1; NTIS No. PB91-103523.
U.S. Department of Agriculture. (1987). CSFII: Women 19-50 Years and Their Children 1-5 Years, 4 Days, 1985. U.S. Department of Agriculture, Human Nutrition Information Service, Nationwide Food Consumption Survey, Continuing Survey of Food Intakes by Individuals, Rep. 85-4; NTIS No. PB88-110101.
U.S. Department of Agriculture. (1993). Food and Nutrient Intakes by Individuals in the United States, 1 Day, 1987-88. U.S. Department of Agriculture, Human Nutrition Information Service, Nationwide Food Consumption Survey, Rep. 87-I-1; NTIS No. PB94-168325.
U.S. Department of Agriculture, Agricultural Research Service. (1999). Food and Nutrient Intakes by Children 1994-96, 1998; ARS Food Surveys Research Group Table Set 17. Retrieved May 21, 2002, from http://www.barc.usda.gov/bhnrc/ foodsurvey/pdf/scs_all.pdf.
U.S. Department of Agriculture, Agricultural Research Service. (2000a). Continuing Survey of Food Intakes by Individuals 1994-96, 1998 [CD-ROM]. NTIS No. PB2000-500027.
U.S. Department of Agriculture, Agricultural Research Service. (2000b). Pyramid Servings Intakes by U.S. Children and Adults: 1994-96, 1998; ARS Community Nutrition Research Group Table Set No. 1. Retrieved May 21, 2002, from http://www.barc.usda.gov/bhnrc/cnrg/tables.pdf.
U.S. Department of Agriculture, Center for Nutrition Policy and Promotion. (1996). The Food Guide Pyramid (sl. rev., Home and Garden Bulletin No. 252). Washington, DC: U.S. Government Printing Office. Retrieved May 21, 2002, from http://www.usda.gov/cnpp/Pubs/Pyramid/fdgdpyr1.pdf.
U.S. Department of Agriculture and U.S. Department of Health and Human Services. (2000). Nutrition and Your Health: Dietary Guidelines for Americans (5th ed., Home and Garden Bulletin No. 232). Washington, DC: U.S. Government Printing Office. Retrieved May 21, 2002, from http://www.usda.gov/cnpp/ DietGd.pdf.
U.S. Department of Health and Human Services. (2001). The Surgeon General's Call to Action to Prevent and Decrease Overweight and Obesity. Rockville, MD: Public Health Service, Office of the Surgeon General. Retrieved May 21, 2002, from http://www.surgeongeneral.gov/topics/obesity/calltoaction /CalltoAction.pdf.
U.S. Department of Health and Human Services, Centers for Disease Control and Prevention. (1996). Physical Activity and Health: A Report of the Surgeon General. NTIS No. PB97-159149. Atlanta, GA.
U.S. Department of Health and Human Services, National Center for Health Statistics. (2001). Table 70: Overweight children and adolescents 6-19 years of age, according to sex, age, race, and Hispanic origin: United States, selected years 1963-65 through 1988-94. In Health United States 2001 with Urban and Rural Health Chartbook. Retrieved June 25, 2002, from http://www.cdc.gov/nchs/data/hus/hus01.pdf.
Weinsier, R.L., Hunter, G.R., Heini, A.F., Goran, M.I., & Sell, S.M. (1998). The etiology of obesity: Relative contribution of metabolic factors, diet, and physical activity. American Journal of Medicine 105(2), 145-150.
Wyshak, G. (2000). Teenaged girls, carbonated beverage consumption, and bone fractures. Archives of Pediatric and Adolescent Medicine, 154, 610-613.
Cecilia Wilkinson Enns, MS, RD
Sharon J. Mickle, BS
Joseph D. Goldman, MA
U.S. Department of Agriculture
Agricultural Research Service
COPYRIGHT 2003 Superintendent Of Documents
COPYRIGHT 2004 Gale Group