Kathleen L. Keller

Television Food Advertising to Children: A Global Perspective

OBJECTIVES We compared television food advertising to children in several countries. METHODS We undertook a collaboration among 13 research groups in Australia, Asia, Western Europe, and North and South America. Each group recorded programming for 2 weekdays and 2 weekend days between 6:00 and 22:00, for the 3 channels most watched by children, between October 2007 and March 2008. We classified food advertisements as core (nutrient dense, low in energy), noncore (high in undesirable nutrients or energy, as defined by dietary standards), or miscellaneous. We also categorized thematic content (promotional characters and premiums). RESULTS Food advertisements composed 11% to 29% of advertisements. Noncore foods were featured in 53% to 87% of food advertisements, and the rate of noncore food advertising was higher during childrens peak viewing times. Most food advertisements containing persuasive marketing were for noncore products. CONCLUSIONS Across all sampled countries, children were exposed to high volumes of television advertising for unhealthy foods, featuring child-oriented persuasive techniques. Because of the proven connections between food advertising, preferences, and consumption, our findings lend support to calls for regulation of food advertising during childrens peak viewing times.

Genetic taste sensitivity to 6-n-propylthiouracil influences food preference and reported intake in preschool children.

Adult tasters of 6-n-propylthiouracil (PROP) are more sensitive to bitter taste and fattiness in foods, and often show lower acceptance of foods that are high in these taste qualities. This study hypothesized that PROP taster children would show lower acceptance of these same foods. Sixty-seven preschool children were classified as PROP tasters (N = 43) or nontasters (N = 24) using a suprathreshold screening solution. Children rated acceptance of 10 bitter and/or fat-containing foods using a 5-pt. facial scale. Parents completed a food frequency questionnaire to estimate their childs intake. Taster children showed lower acceptance of raw broccoli and American cheese (p < or = 0 x 05). Taster-girls showed lower acceptance of full-fat milk than nontaster-girls (p < or = 0 x 05). This effect was not seen in boys. Nontasters reported more daily intake of discretionary fats than tasters (p < or = 0 x 05), an effect largely due to nontaster-girls, in whom reported intake was 2--3 more servings per day than taster-girls, and boys of both groups. These data suggest that PROP taste sensitivity plays a role in acceptance of certain bitter cruciferous vegetables and cheese by young children. In addition, taster group differences in acceptance of full-fat milk and intake of discretionary fats seen in girls, suggest that gender-specific environmental factors might interact with genetics to influence fat preferences.

Common Variants in the CD36 Gene Are Associated With Oral Fat Perception, Fat Preferences, and Obesity in African Americans

Animal studies show that CD36, a fatty acid translocase, is involved in fat detection and preference, but these findings have not been reported in humans. The objective of this study was to determine whether human genetic variation in 5 common CD36 polymorphisms is associated with oral fat perception of Italian salad dressings, self‐reported acceptance of high‐fat foods and obesity in African‐American adults (n = 317). Ratings of perceived oiliness, fat content, and creaminess were assessed on a 170‐mm visual analogue scale (VAS) in response to salad dressings that were 5%, 35%, and 55% fat‐by‐weight content. Acceptance of added fats and oils and high‐fat foods was self‐reported and anthropometric measures were taken in the laboratory. DNA was isolated from saliva and genotyped at 5 CD36 polymorphisms. Three polymorphisms, rs1761667, rs3840546, and rs1527483 were associated with the outcomes. Participants with the A/A genotype at rs1761667 reported greater perceived creaminess, regardless of the fat concentration of the salad dressings (P < 0.01) and higher mean acceptance of added fats and oils (P = 0.02) compared to those with other genotypes at this site. Individuals who had C/T or T/T genotypes at rs1527483 also perceived greater fat content in the salad dressings, independent of fat concentration (P = 0.03). BMI and waist circumference were higher in participants who were homozygous for a deletion (D/D) at rs3840546, compared to I/D or D/D individuals (P < 0.001), but only 2 D/D individuals were tested, so this finding needs replication. This is the first study to demonstrate an association between common variants in CD36 and fat ingestive behaviors in humans.

Increased sweetened beverage intake is associated with reduced milk and calcium intake in 3- to 7-year-old children at multi-item laboratory lunches.

Dietary survey data show that intake of sugar-sweetened beverages is negatively associated with intake of milk, but these findings have yet to be confirmed by laboratory feeding studies. The objectives of the present study were to analyze childrens intake across two laboratory-based ad libitum lunches to (a) investigate the relationships between intake of sweetened beverages, milk, and calcium, and (b) explore relationships between beverage consumption and child age and weight status. Data were extracted from a cohort of 126 3- to 7-year-old twins from diverse ethnic backgrounds who participated in a cross-sectional study (conducted from November 1999 to September 2002) designed to determine the genetic and environmental contributions to eating and body weight. At two visits, children ate ad libitum from lunches that offered a variety of sugar-sweetened and calcium-rich beverages. Total beverage and nutrient intakes were computed from the test meals. Weight, height, and waist circumference were assessed on the final visit. Regression analyses tested the associations among intake of sweetened beverages, calcium, and milk (primary aim), and whether these variables were associated with child age and weight status (secondary aim). Sweetened beverage intake was negatively correlated with both milk (P<0.01) and calcium (P<0.01) intakes, and these relationships remained after controlling for age, sex, and ethnicity (P<0.01). Child age was negatively associated with milk intake (r=-0.22, P<0.01) but positively associated with intake of sweetened beverages (r=0.27, P<0.01). Results support the notion that sugar-sweetened beverages displace milk in a single meal, and this phenomenon may vary with child age. Due to the cross-sectional nature of this study, future investigations are needed to determine the long-term implications of this consumption pattern. The possibility that limiting sweetened beverages may help optimize dietary calcium during childhood is a topic that merits further research.

Maternal restriction of children's eating and encouragements to eat as the 'non-shared environment': a pilot study using the child feeding questionnaire.

Objective:This pilot study tested whether maternal feeding attitudes and styles towards children are part of the ‘shared’ or ‘non-shared’ home environment. A secondary aim was to test whether within-family differences in maternal feeding attitudes and styles relate to within-family differences in child weight status.Methods:Mothers of 3- to 7-year-old sibling pairs (N=15 pairs) completed the Child Feeding Questionnaire (CFQ), which assessed feeding attitudes (perceived responsibility, perceived child overweight and child weight concern) and feeding styles (monitoring, restriction and pressure to eat) towards children. Mothers rated each sibling separately. Child weight and height were measured and converted to body mass index (BMI) z-scores. Intraclass correlations tested the familial associations for each CFQ subscale. Pearsons correlations tested whether within-family differences in CFQ subscales were related to within-family differences in child BMI z-scores.Results:Perceived responsibility (ρ=0.77, P=0.0004), perceived child overweight (ρ=0.99, P<0.0001) and monitoring (ρ=0.57, P=0.01) showed significant familial correlations. Mothers reported significantly greater weight concern (r=0.85, P=0.02) and reduced pressure to eat (r=−0.80, P=0.03) towards heavier than thinner children within families.Conclusion:Whether or not maternal feeding practices are shared or non-shared components of the home environment depends on the specific feeding domain being measured. Restrictive feeding practices and encouragements to eat by mothers might be tested as non-shared environmental variables in genetics studies of childhood obesity.

The impact of food branding on children's eating behavior and obesity

Branding is a technique used by the food industry to create a recognizable image to attract consumers and hopefully boost sales of the product. Children recognize food brands from a young age, but their impact on the development of eating behaviors and obesity is unclear. In addition, the notion that some branding techniques may be used to increase intake of healthful foods, like fruits and vegetables, has not been rigorously investigated. Three laboratory-based intake studies designed to test the impact of common food brands on childrens eating habits are presented. In the first study, four to six year-old children (n=43) were exposed to ad libitum test-meals where foods were presented either with or without their associated branding. In the second study, a novel food brand based Stroop task was developed and tested to assess childrens cognitive response to food brands, and following this procedure, seven to nine year-old children (n=41) ate ad libitum test-meals consisting of foods packaged with or without a logo from a popular fast food restaurant. Finally, a pilot intervention was conducted with four to five year-old children (n=16) to demonstrate the efficacy of using licensed (spokes) characters to package and promote intake of fruits and vegetables. These studies demonstrate that branding is an important influence on what and how much children eat, but some children may be more susceptible to these influences than others. Future studies are needed to better understand the influence that child age, sex, and obesity has on response to food branding and marketing.

Usefulness of different techniques for measuring body composition changes during weight loss in overweight and obese women

The objective was to compare measures from dual-energy X-ray absorptiometry (DXA), bioelectrical impedance analysis (BIA) and anthropometry with a reference four-compartment model to estimate fat mass (FM) and fat-free mass (FFM) changes in overweight and obese women after a weight-loss programme. Forty-eight women (age 39.8 +/- 5.8 years; weight 79.2 +/- 11.8 kg; BMI 30.7 +/- 3.6 kg/m2) were studied in an out-patient weight-loss programme, before and after the 16-month intervention. Women attended weekly meetings for the first 4 months, followed by monthly meetings from 4 to 12 months. Body composition variables were measured by the following techniques: DXA, anthropometry (waist circumference-based model; Antrform), BIA using Tanita (TBF-310) and Omron (BF300) and a reference four-compartment model. Body weight decreased significantly ( - 3.3 (sd 3.1) kg) across the intervention. At baseline and after the intervention, FM, percentage FM and FFM assessed by Antrform, Tanita, BF300 and DXA differed significantly from the reference method (P < or = 0.001), with the exception of FFM assessed by Tanita (baseline P = 0.071 and after P = 0.007). DXA significantly overestimated the change in FM and percentage FM across weight loss ( - 4.5 v. - 3.3 kg; P 0.05) from the reference model in any body composition variables. We conclude that these methods are widely used in clinical settings, but should not be applied interchangeably to detect changes in body composition. Furthermore, the several clinical methods were not accurate enough for tracking body composition changes in overweight and obese premenopausal women after a weight-loss programme.

Mechanisms of the portion size effect. What is known and where do we go from here

Childhood obesity is a persistent problem worldwide, and of particular concern in the United States. Clarifying the role of the food environment in promoting overeating is an important step toward reducing the prevalence of obesity. One potential contributor to the obesity epidemic is the increased portion sizes of foods commonly served. Portion sizes of foods served both at home and away from home have dramatically increased over the past 40 years. Consistently, short-term studies have demonstrated that increasing portion size leads to increased food intake in adults and children, a phenomenon known as the portion size effect. However, the mechanisms underlying this effect are poorly understood. Understanding these mechanisms could assist in clarifying the relationship between portion size and weight status and help inform the development of effective obesity interventions. First, we review the role of visual cues, such as plate size, unit, and utensil size as a potential moderator of the portion size effect. In addition, we discuss meal microstructure components including bite size, rate, and frequency, as these may be altered in response to different portion sizes. We also review theories that implicate post-ingestive, flavor-nutrient learning as a key moderator of the portion size effect. Furthermore, we present preliminary data from an ongoing study that is applying neuroimaging to better understand these mechanisms and identify modifiable child characteristics that could be targeted in obesity interventions. Our tentative findings suggest that individual differences in cognitive (e.g. loss of control eating) and neural responses to food cues may be critical in understanding the mechanisms of the portion size effect. To advance this research area, studies that integrate measures of individual subject-level differences with assessment of food-related characteristics are needed.

Sex Differences in the Effects of Inherited Bitter Thiourea Sensitivity on Body Weight in 4–6-Year-Old Children

Previous studies have shown that inherited taste blindness to bitter compounds like 6‐n‐propylthiouracil (PROP) may be a risk factor for obesity, but this literature has been highly controversial. The objectives of this study were (i) to confirm findings that show an interaction between PROP status and sex on BMI z‐score, and (ii) to determine if sex also interacts with variations in TAS2R38 (phenylthiocarbamide (PTC) genotype) to influence weight status in 4–6 year olds. Also, we tested whether nontaster children consumed more fat and total energy at laboratory‐based meals. Seventy‐two ethnically diverse children who ranged in weight status were classified as tasters (N = 52) or nontasters (N = 20) using a standard PROP screening solution. Anthropometric measures were taken, and at the end of each visit, children ate ad libitum from test meals intended for exploratory purposes. Genomic DNA was extracted from saliva and alleles at TAS2R38 were genotyped for A49P polymorphisms. In 75.8% of children, PTC genotype predicted PROP phenotype, whereas in 24.4%, genotype did not predict phenotype. PROP nontaster males had higher BMI z‐scores than taster‐males and females in both groups (P < 0.05), but due to a three‐way interaction between PROP phenotype, TAS2R38 genotype, and sex, this relationship was only true for children who were homozygous for the bitter‐insensitive allele (P < 0.0005). There were no differences in test‐meal intake as a function of PROP phenotype or TAS2R38 genotype. These results suggest that the TAS2R38 variation, PROP phenotype, and sex interact to impact obesity risk in children. Future studies should be done to determine how this trait influences energy balance.

Review of evaluation tools used to assess the impact of nutrition education on dietary intake and quality, weight management practices, and physical activity of low-income audiences:

Nutrition education programs and social marketing campaigns frequently focus on low-income audiences with the goal of improving dietary intake and quality, weight management practices, and physical activity. The impact of nutrition education can be assessed by measuring change in relation to any or all of these broad variables. Unfortunately, little information is available concerning the reliability, validity, and sensitivity to change of measures used to assess these constructs with low-income audiences of adults and adolescents. This article reviews the literature and discusses the types of available measures that have been used and evaluated for the above audiences. It describes specific measures used to assess total diet, consumption of food groups from the Food Guide Pyramid, and behaviors related to weight management and physical activity. Overall, this review suggests that there is a critical need for additional development and evaluation of dietary quality measurement tools for low-income and minority audiences.