|
|
||||||||
Department of Preventive and Community Dentistry, University of Iowa College of Dentistry (T.A.M., J.M.E., B.B., S.M.L.)
Clinical Research Center, University of Iowa Roy H. and Lucille A. Carver College of Medicine (P.J.S.), University of Iowa, Iowa City, Iowa
Address reprint requests to: Teresa A. Marshall, PhD, Assistant Professor, Department of Preventive and Community Dentistry, University of Iowa College of Dentistry, N335 Dental Science Building, Iowa City, IA 52242. E-mail: teresa-marshall{at}uiowa.edu
| ABSTRACT |
|---|
|
|
|---|
Objective: To describe dairy food, 100% juice and added sugar beverage intakes, contributions of dairy foods to diet quality, and effects of beverages on diet quality in young children.
Methods: We surveyed participants in the Iowa Fluoride Study (n = 645) at ages 1, 2, 3, 4 and 5 years and calculated intakes for 15 years (i.e. weighted averages). Nutrient, dairy food and beverage intakes were obtained from 3-day diaries; nutrient adequacy ratios were calculated as the nutrient intake to Recommended Dietary Allowance/Adequate Intake ratio; and dairy-dependent percentages were calculated as fractions of total diet nutrient adequacy ratios (truncated at 1) not met by non-dairy foods.
Results: Milk intakes were inversely associated with intakes of juice drinks (2, 4, 5 and 15 years), soda pop (2, 3, 4, 5 and 15 years) and added sugar beverages (2, 3, 4, 5 and 15 years). Dairy dependent fractions of 15 year nutrient adequacy ratios were 68% for calcium and 61% for vitamin D. Higher 15 year calcium adequacy was predicted by higher energy, higher other dairy and lower added sugar beverage intakes while higher vitamin D adequacy was predicted by higher energy and higher other dairy intakes. Overall diet quality was predicted by higher energy, higher other dairy, lower 100% juice and lower added sugar beverage intakes.
Conclusions: Dairy foods remain an important source of calcium and vitamin D, while added sugar beverages and, to a lesser extent, 100% juice decrease diet quality of young children.
Key words: diet quality, milk, juice, soda pop, AI = adequate intake, CSFII = Continuing Survey of Food Intakes by Individuals, IFS = Iowa Fluoride Study, MAR = mean adequacy ratio, NAR = nutrient adequacy ratio, RDA = recommended dietary allowance, USDA = United States Department of Agriculture
| INTRODUCTION |
|---|
|
|
|---|
Contemporary dietary patterns suggest that milk intakes have declined while sugared beverage intakes (e.g., 100% juice, juice drinks, soda pop) have increased [310]. Cavadini et al. [4] compared survey data collected by the USDA in 1965 and 1996, and reported that decreased milk intakes were accompanied by increased soft drink and non-citrus juice intakes in adolescents aged 1118 years. Coincident with declining milk intakes, calcium intakes have declined and are lower than recommended Adequate Intakes (AI) [4,611]. Among children aged 217 years participating in the 199496 Continuing Survey of Food Intakes by Individuals (CSFII), milk intake was positively associated with recommended intakes of vitamin A, folate, vitamin B-12, calcium and magnesium, and 100% juice intake with recommended intakes of vitamin C and folate [12]. However, soda pop intake was inversely associated with recommended intakes of vitamin A, calcium and magnesium in these children [12]. Harnack et al. [7] reported that preschool- and school-aged children with high (
9 oz/day) soda intakes had higher energy intakes and lower protein, riboflavin, folate, vitamin A, vitamin C, calcium and phosphorus intakes than nonconsumers participating in the 1994 CSFII. Research relying on national survey data is cross-sectional in design and relies on groups with broad age ranges. The study design does not permit following these children over time, so it is not possible to gain insight into changing habits during early childhood.
Fisher et al. [6] reported that beverage intakes of 5-year-old girls paralleled their mothers beverage habits, and that soft drink intakes were inversely related to both milk and calcium intakes in daughters and mothers. Contemporary longitudinal studies of young childrens diets [1315] have examined associations between sugared beverage intakes and growth and have reported milk intakes, but have not investigated relationships among sugared beverage, milk and calcium intakes. Although one would expect that associations observed in older children occur in younger children, evidenced-based research describing the effects of contemporary beverage patterns on calcium intake and overall diet quality at multiple ages during early childhood is lacking. Knowledge of longitudinal beverage choices, including how early beverage choices influence later beverage choices, could be important to establish guidelines for life-long healthy eating habits.
The purposes of this paper are to describe patterns of milk, other dairy food and sugared beverage intakes, the contribution of dairy foods to diet quality, and the extent to which concurrent consumption of sugared beverages influences diet quality in a longitudinal cohort of young children. We hypothesize that dairy products are the primary contributor of calcium and vitamin D and a significant contributor of riboflavin, folate and vitamin A to young childrens diets, and that replacement of milk by sugar-containing beverages is associated with lower intakes of these nutrients.
| METHODS |
|---|
|
|
|---|
Design Overview
Parents were mailed IFS questionnaires and 3-day food and beverage diaries when their children were 6 weeks of age, 3, 6, 9 and 12 months of age, every 4 months through 3 years of age and every 6 months thereafter. IFS questionnaires were designed to obtain information regarding their childrens beverage intake, general health and oral health behaviors.
Diet Analyses
Three-day food and beverage diaries completed at 1, 2, 3, 4 and 5 years of age are the focus of the present analyses. Annual diaries were evaluated individually and cumulatively using area-under-the-curve analyses. If the subject did not return a specific 3-day food and beverage diary (e.g., 24 month), then the previous diary (e.g., 20 month) was substituted. If this diary was also missing, then the subsequent diary (e.g., 28 month) was substituted for the yearly diary. If neither was available, then that subject was omitted for that year. Inclusion in combined age 15 area-under-the-curve analysis required a minimum of 4 diaries including the 1- and 5-year diaries or suitable substitutions. Area-under-the-curve was calculated using the trapezoidal rule to estimate the lifetime mean intake. When data were missing for a year, then the trapezoidal segment covered two years. For instance, a subject with milk intakes at 1, 2, 3 and 5 y, respectively, has a 15 year weighted average milk intake calculated from the 12-year mean intake, the 23 year mean intake and twice the 35 year mean intake.
On each diary, parents were asked to record the types and quantities of all foods and beverages consumed by their children for one weekend day and two weekdays. Detailed information was requested regarding beverages, including brand names, types of preparation, and sources of water used in preparation. All entries from the 3-day food and beverage diaries were coded and verified by registered dietitians to create a Food and Beverage Intake Table. Human milk intake was estimated using models of mean intakes [22]. Total dietary intake was estimated at 4.6 oz/kg/day at 12 months. The volume of infant foods and beverages consumed was subtracted from this volume, and the remainder was estimated to be breast milk. The percentage of subjects consuming any human was 9.8%, 1.9%, 1.6%, 0.7% and 0.0% at 1, 2, 3, 4 and 5 years of age, respectively.
Dairy foods and all beverages were coded according to food type (e.g., fluid milk, cheese, 100% juice, juice drink, water). When possible, dairy products added to foods were coded separatelybroccoli with cheese sauce was coded as two foods, broccoli and cheese sauce. For foods having cheese or milk as an ingredient (e.g., lasagna, cheeseburger), the dairy component was estimated from ingredient weights. Calcium and vitamin D intakes from these foods were assigned to dairy foods; all other nutrient intakes from these foods (e.g., protein, zinc) were attributed to non-dairy foods. Dairy foods were the primary source of calcium and vitamin D in mixed dishes, but not necessarily the primary source of other nutrients. This conservative approach systematically underestimates the contribution of dairy foods to these nutrients. Dairy foods include milk, cheese, yogurt and dairy desserts. Added sugar beverages include juice drinks, regular soda pop, powdered beverages and sports drinks.
A Nutrient Table was created from nutrient data obtained from the USDA (Nutrient Database for Standard Reference 12, Agriculture Research Service), the Minnesota Nutrient Database (Nutrition Coding Center NDS-R, Version 4.01; Minneapolis, MN) and manufacturers data. A relational database (Microsoft Access, version SR-1; Redmond, WA) was used to link the Food and Beverage Intake Table and the Nutrient Table for calculation of food and nutrient intakes. Weighted averages based on weekend and weekday consumption were calculated to reflect average consumption over a week.
Diet quality indices were created using the Dietary Reference Intakes [11] as a reference for adequacy of nutrient intakes [2324]. The nutrient adequacy ratio (NAR) for a given nutrient is the ratio of an individuals mean daily intake to the age-specific Recommended Dietary Allowance (RDA) or AI, if an RDA was not available. The mean adequacy ratio (MAR) is the average of an individuals NARs and is an index of overall diet quality [2324]. The MAR was calculated from NARs for protein, 11 vitamins (thiamin, riboflavin, niacin, folate, pantothenic acid, vitamin B-6, vitamin B-12, vitamin C, vitamin A, vitamin D, vitamin E) and 7 minerals (calcium, copper, iron, magnesium, phosphorous, selenium, zinc). NARs were truncated at 1 for calculation of the MAR to prevent an excess intake of one nutrient from compensating for inadequate intakes of other nutrients.
NARs and MARs were calculated for all foods and beverages (i.e., total diet), all non-dairy foods and beverages (i.e., non-dairy diet) and all dairy foods and beverages (i.e., dairy diet). NARs were truncated at 1.0 to distinguish between adequate and greater than adequate intakes to prevent an overestimation of dairy dependence. Dairy-dependent percentages of total diet NARs and MARs were calculated to determine the dietary significance of dairy foods after considering the nutrient contributions of non-dairy foods and beverages. Dairy-dependent percentages were calculated as follows: (total diet NAR non-dairy NAR) otal diet NAR * 100.
Statistical Analysis
Cross sectional analyses of data collected at 1, 2, 3, 4, 5 years and for 15 years were completed using SAS (SAS, version 8.01, Cary, NC, 2000). Subject characteristics (i.e., gender, birth order, household income, parental age and parental education) were categorized and presented as percentages. Food, beverage and nutrient intakes and NARs were reported as medians (25th, 75th percentiles). The sign test was used to identify changes in sequential yearly trends in food, beverage and nutrient intakes. Spearman correlation coefficients were used to identify associations between dairy foods and beverage intakes. General linear regression models were used to describe the relationships among milk, other dairy foods (e.g., cheese, yogurt, dairy desserts), 100% juice, added sugar beverages (e.g., juice drinks, regular soda pop, regular powdered beverages, sports drinks) and energy intakes and NARs. A p-value of <0.05 was considered statistically significant.
| RESULTS |
|---|
|
|
|---|
|
|
|
Median (25th, 75th) NARs and MARs based on all foods and beverages (total diet), non-dairy foods and beverages (non-dairy diet) and dairy foods and beverages (dairy diet), and the median (25th, 75th) percentages of total diet NARs that depended on intake of dairy foods (dairy-dependent percentages) are presented in Tables 4a (1 year), 4b (2 year), 4c (3 year), 4d (4 year), 4e (5 year) and 4f (15 years). Although 15 year dairy NARs (Table 4f were greater than 0.50 for protein, riboflavin, vitamin B-12, magnesium and zinc, the non-dairy NARs were 1.00 and the dairy-dependent percentages of the total diet NARs were 0 for these nutrients. One through 5 year dairy NARs were greater than 0.50, non-dairy NARs ranged from 0.310.64, and dairy dependent percentages of the total diet NARs were 34%, 61%, and 68%, respectively, for pantothenic acid, vitamin D, and calcium. The contribution of dairy foods to the yearly MARs (Tables 4a(e) ranged from 0.420.50, with 1014% of the yearly total diet MAR dependent on dairy foods. Dairy-dependent percentages of total diet NARs increased after 3 years for pantothenic acid, vitamin A, calcium, and magnesium (p < 0.001).
|
|
|
|
|
|
General linear models that included intakes of total energy, milk, other dairy foods, 100% juice, and other sugar beverages were used to identify associations among these variables and NARs (not truncated), and to predict the variation in NARs explained by the models for 15 years Table 5. Energy was associated with intakes of both milk (r = 0.254, p < 0.001) and other dairy foods (r = 0.332; p < 0.001). In general, energy demonstrated strong, statistically significant, positive associations with each NAR. Milk intakes demonstrated weak, but statistically significant, inverse associations with several NARs. In contrast, other dairy foods demonstrated strong, statistically significant, positive associations with protein, riboflavin, pantothenic acid, vitamin B-12, vitamin D, calcium, magnesium, phosphorous and zinc. One-hundred-percent juice demonstrated a strong, statistically significant, positive association with the vitamin C NAR, and strong statistically significant, negative associations with multiple other NARs and the MAR. Other sugar beverages were inversely associated with most NARs and the MAR. Models including energy, milk, other dairy foods, 100% juice and other sugar beverages explained a significant percentage of the variance in each NAR and the MAR.
|
| DISCUSSION |
|---|
Recognizing the challenges in defining the contribution of dairy foods to diet quality, we chose to evaluate the contribution of dairy foods to individual NARs and MARs and to determine the portion of NARs and MARs that depended on dairy food consumption. Dairy associated NARs and MARs acknowledge the wide range and quantity of nutrients available from dairy foods, while the dairy-dependent percentages offer a conservative estimate of dairy foods role in the diet and recognize contributions of other nutrient dense foods and beverages.
Our results suggest that, while dairy foods provide more than 50% of the NARs for protein, riboflavin, vitamin B-12, magnesium and zinc, young children do not rely on dairy foods for adequate intakes of these nutrients. However, young children do rely on dairy foods to achieve adequate intakes of pantothenic acid, vitamin D and calcium, and this reliance increases with age for pantothenic acid and calcium. The increased reliance on dairy foods for adequate intakes after 3 years of age suggests that dairy foods contribute a greater percentage as nutrient requirements increase (i.e., most RDAs and AIs increase at 4 years). The observed increase in consumption of added sugar beverages of limited nutrient density at this time could be associated with lower intakes of nutrient dense foods, thus diluting the contribution of non-dairy foods to diet quality and emphasizing the contribution of dairy foods. Similarly, Kant et al. [29] reported that increased numbers of low nutrient-dense foods consumed were associated with decreased intakes of dairy foods and micronutrients, including vitamin B-12, folate, calcium and magnesium in both boys and girls, aged 818 years participating in the third National Health and Nutrition Examination Survey, 19881994.
Median daily intakes of milk and other dairy foods were slightly less than USDAs Food Guide Pyramid recommendation of 2 servings/d [30]. This finding supports observations by Munoz et al. [31] who reported that 67% of children participating in the 19891991 CSFII did not consume the recommended number of dairy foods servings. Furthermore, overall milk intakes were not related to other dairy food intakes in our study, suggesting that children who dont drink milk are not compensating with other dairy foods. Our subjects milk intakes (327364 g/d or 11.312.5 oz/d) were similar to intakes reported by Skinner et al. (11.112.2 oz/d) [15] for children ranging from 2772 months of age and Dennison et al. (9.811.0 oz/d) [32] for 2-year and 5-year old children.
We believe that we are the first to comprehensively investigate associations among dairy foods, 100% juice, added sugar beverages and overall diet quality in a young cohort. The relationships that we observed among beverage intakes are consistent with and expand upon results from national surveys [45,712]. Although milk was the primary dairy product consumed by our subjects and contributed a greater quantity of nutrients to the diet than other dairy foods, other dairy foods were a better predictor of nutrient adequacy than milk. Beginning as early as 2 years of age, milk intakes of our subjects were inversely associated with total added sugar beverages, as well as juice drinks and soda-pop. The cumulative consumption of added sugar beverages was inversely associated with overall diet quality, as well as adequacy of multiple nutrient intakes. Milk intakes were inversely associated with 100% juice at age 2 only; and cumulative consumption was positively associated with adequacy of vitamin C, but negatively associated with adequacy of multiple other nutrients. Harnack et al. [7], using data from the 1994 CSFII, reported that preschool children with higher soda-pop intakes had lower milk and micronutrient intakes, but they did not explore associations among milk, 100% juice and micronutrient intakes. Likewise, Skinner et al. [14] reported that milk intakes were negatively associated with soda-pop, but not 100% juice intakes; and that folate and vitamin C intakes were higher and vitamin D intake lower in children consuming
12 oz 100% juice at 2432 months.
This study has several limitations inherent to dietary studies. First, all data were parent or caregiver (e.g., babysitter) reported, and recorded intakes could reflect attitudes about what should be consumed as opposed to what was consumed. The children were generally from middle income, educated families, and are not representative of children throughout Iowa or the United States.
| CONCLUSION |
|---|
|
|
|---|
| ACKNOWLEDGMENTS |
|---|
|
|
|---|
Received October 24, 2003.
Revised May 7, 2004.
| REFERENCES |
|---|
|
|
|---|
http://www4.nas.edu/IOM/IOMHome.nsf/Pages/FNB+Reports
Accessed 8/5/02.
This article has been cited by other articles:
![]() |
S. Lim, W. Sohn, B. A. Burt, A. M. Sandretto, J. L. Kolker, T. A. Marshall, and A. I. Ismail Cariogenicity of Soft Drinks, Milk and Fruit Juice in Low-Income African-American Children: A Longitudinal Study J Am Dent Assoc, July 1, 2008; 139(7): 959 - 967. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. E. O'Neil and T. A. Nicklas A Review of the Relationship Between 100% Fruit Juice Consumption and Weight in Children and Adolescents American Journal of Lifestyle Medicine, July 1, 2008; 2(4): 315 - 354. [Abstract] [PDF] |
||||
![]() |
L. R. Vartanian, M. B. Schwartz, and K. D. Brownell Effects of Soft Drink Consumption on Nutrition and Health: A Systematic Review and Meta-Analysis Am J Public Health, April 1, 2007; 97(4): 667 - 675. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. A. Marshall, J. M. Eichenberger-Gilmore, M. A. Larson, J. J. Warren, and S. M. Levy Comparison of the intakes of sugars by young children with and without dental caries experience J Am Dent Assoc, January 1, 2007; 138(1): 39 - 46. [Abstract] [Full Text] [PDF] |
||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |