Validity of children's food portion estimates: a comparison of 2 measurement aids.

BACKGROUND: Policy and clinical decisions regarding children's nutrition are often based on dietary intake estimates from self-reports. The accuracy of these estimates depends on memory of both the type of food eaten and the amount consumed. Although children's self-reports of food intake are widely used, there is little research on their ability to estimate food portions. OBJECTIVE: To assess the validity of children's estimates of the food portions they consume by means of 2 types of measurement aids: standard 2-dimensional food portion visuals and manipulative props. DESIGN: Randomized controlled trial. PARTICIPANTS: Fifty-four African American girls aged 8 to 12 years. MAIN OUTCOME MEASURES: Girls were served a standard meal and actual intake was assessed by weighing food portions before and after the meal. On completion of the meal, dietitians collected food recalls and portion size estimates from the girls by means of both manipulative props and 2-dimensional food portion visuals, administered in a randomized order. RESULTS: Absolute value percentage differences between actual and estimated grams of food consumed averaged 58.0% (SD, 102.7%) for manipulative props and 32.8% (SD, 72.8%) for 2-dimensional food portion visuals. Spearman correlations between actual and estimated intakes with both portion size measurement aids were high (range, r = 0.56 to 0.79; all P<.001), with the exception of bread intake (r = 0.16, P =.43). Correlations with actual intakes did not differ significantly between the 2 methods. CONCLUSIONS: Children's self-reported portion size estimates are appropriate for ranking children's relative intakes, but they result in sizable errors in quantitative estimates of food and energy intakes. Caution should be used in interpreting quantitative dietary intake estimates derived from children's self-reports.

Primary care interventions to reduce television viewing in African-American children.

BACKGROUND: Data are lacking on primary care interventions to reduce children's television viewing. Low-income African-American children watch greater amounts of television than their peers. DESIGN/METHODS: A randomized controlled pilot and feasibility trial was conducted. Twenty-eight families with 7- to 12-year-old African-American children receiving primary care at an urban community clinic serving a low-income population were randomized to receive counseling alone or counseling plus a behavioral intervention that included an electronic television time manager. The main outcome was hours of children's television, videotape, and video game use. Parents/guardians and children completed baseline and 4-week follow-up self-report surveys. Additional outcomes included overall household television use, time spent in organized physical activity and playing outside, and meals eaten by the child while watching television. RESULTS: Both intervention groups reported similar decreases in children's television, videotape, and video game use (mean changes of -13.7, SD=26.1 and -14.1, SD=16.8 hours per week). The behavioral intervention group reported significantly greater increases in organized physical activity (changes of +2.5, SD=5.9 and -3.6, SD=4.7 hours per week; p =0.004) and nearly significant greater increases in playing outside (changes of 1.0, SD=5.9 and -4.7, SD=9.4 hours per week; p <0.06). Changes in overall household television use and meals eaten while watching television also appeared to favor the behavioral intervention, with small to medium effect sizes, but differences were not statistically significant. CONCLUSIONS: This small pilot and feasibility study evaluated two promising primary care-based interventions to reduce television, videotape, and video game use among low-income African-American children. The effects on physical activity suggest that the behavioral intervention may be more effective.