Obesity status transitions across the elementary years: use of Markov chain modelling.

OBJECTIVE: The objective of this study was to assess overweight and obesity status transition probabilities using first-order Markov transition models applied to elementary school children. METHOD: Complete longitudinal data across 11 assessments were available from 1494 elementary school children (from 7599 students in 41 out of 45 schools in a Southeast Texas school district) from kindergarten to the beginning of the fifth grade. Heights and weights were measured by trained school nurses using standard procedures at the beginning and end of each school year for the 11 consecutive assessments. To estimate the transition probabilities, first-order three-state (healthy weight, overweight and obese) Markov transition models were fit to the longitudinal weight status data of all assessment periods. RESULTS: While there was a gradual shift to more children in the overweight or obese category over 5 years, children were most likely to stay in the same weight category as the previous assessment. A consistent seasonal difference in the probability of changing weight status category was seen, with a greater probability of becoming overweight and obese during the summer compared with the school year. The transition probabilities to obesity were higher among boys, Hispanic and non-Hispanic Black, and lower socioeconomic status children. CONCLUSIONS: This study provides the first application of a Markov transition model to child weight status data. The transitions into the overweight and obese categories were small, but persistent, with smaller percentages transitioning out of overweight or obese. Early monitoring and summer intervention strategies are needed to prevent the slow, but relentless, transition into the overweight and obese categories.

The IDEFICS intervention trial to prevent childhood obesity: design and study methods.

INTRODUCTION: One of the major research dimensions of the Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS (IDEFICS) study involved the development, implementation and evaluation of a setting-based community-oriented intervention programme for primary prevention of childhood obesity. In this supplement of Obesity Reviews, a compilation of key results of the IDEFICS intervention is packaged in a series of complementary papers. OBJECTIVE: This paper describes the overall design and methods of the IDEFICS intervention in order to facilitate a comprehensive reading of the supplement. In addition, some 'best practice' examples are described. RESULTS: The IDEFICS intervention trial was conducted to assess whether the IDEFICS intervention prevented obesity in young children aged 2 to 9.9 years. The study was a non-randomized, quasi-experimental trial with one intervention matched to one control region in each of eight participating countries. The intervention was designed following the intervention mapping framework, using a socio-ecological theoretical approach. The intervention was designed to address several key obesity-related behaviours in children, parents, schools and community actors; the primary outcome was the prevalence of overweight/obesity according to the IOTF criteria based on body mass index. The aim was to achieve a reduction of overweight/obesity prevalence in the intervention regions. The intervention was delivered in school and community settings over a 2-year period. Data were collected in the intervention and control cohort regions at baseline and 2 years later. CONCLUSION: This paper offers an introductory framework for a comprehensive reading of this supplement on IDEFICS intervention key results.

Should the IDEFICS outcomes have been expected?

The Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS (IDEFICS) study evaluated with a large sample a comprehensive carefully planned obesity prevention intervention targeting multiple levels of influence that were culturally adapted to the situations in eight European countries. Despite the great effort and attention to detail, the IDEFICS study did not achieve its targeted adiposity or behaviour change objectives. Should we be surprised that the IDEFICS trial did not have its intended effects? We think not, and would have been surprised if it did. Recent research has revealed the lack of consistent meaningful relationships between several apparently obesogenic behaviours and adiposity, weak or no relationships among behavioural change procedures, mediating variables and targeted behaviours and inadequate attention to moderating effects. Future obesity prevention interventions would benefit from a more thorough understanding of the complex relationships that have been hypothesized and the interrelationships with biological factors. While systems modelling has been proposed as providing the solution, important less complex identification of new constructs, new relationships and community interventions are still needed, both to find innovative solutions and to provide input into the systems models. We should question results from cross-sectional studies and be satisfied only with longitudinal or experimental tests of relationships.

Validation of a web-based questionnaire to assess the dietary intake of Brazilian children aged 7-10 years.

BACKGROUND: The Food Intake and Physical Activity of School Children (CAAFE) comprises an online questionnaire to self-report diet and physical activity of Brazilian schoolchildren. BACKGROUND: The present study aimed to assess the validity (matches, omissions and intrusions) and moderating factors of the CAAFE. METHODS: Direct observation was made of foods consumed (five public schools) and child self-reporting on the CAAFE. Additional data included school grade, gender, body mass index, completion of food diary, socioeconomic status and access to computer. Data were analysed using regression. RESULTS: In total, 602 children participated in the study [mean (SD) age 9.5 (1.24) years; 53.6% boys]. On average, there were 43% matches, 29% intrusions and 28% omissions. Matches doubled in third grade compared to the second grade (P = 0.004); matches almost tripled for afternoon snack compared to morning snack (P < 0.001); and matches were 69% higher for children with access to a computer at home (P < 0.01). Intrusions decreased by almost one-half in fifth compared to fourth grades (P = 0.004). Omissions declined significantly in the third and fourth grades but increased in the fifth grade. Omissions were 47% lower for children in the highest income and lower among children who completed the food diary. No differences were found for gender or body mass index. CONCLUSIONS: Children older than 8 years old, who owned a computer and completed a food diary, performed better in the CAAFE. A high incidence of disagreement was found in relation to the schools and the type of meal. Overall matches (43%), intrusions (29%) and omissions (28%) indicate that further studies are required to improve the validity of the CAAFE.

Validation of the Portuguese self-administered computerised 24-hour dietary recall among second-, third- and fourth-grade children.

BACKGROUND: Current methods for assessing children's dietary intake, such as interviewer-administered 24-h dietary recall (24-h DR), are time consuming and resource intensive. Self-administered instruments offer a low-cost diet assessment method for use with children. The present study assessed the validity of the Portuguese self-administered, computerised, 24-h DR (PAC24) against the observation of school lunch. METHODS: Forty-one, 7-10-year-old children from two elementary schools, in Lisbon, were observed during school lunch followed by completion of the PAC24 the next day. Accuracy for reporting items was measured in terms of matches, intrusions and omissions; accuracy for reporting amounts was measured in terms of arithmetic and absolute differences for matches and amounts for omissions and intrusions; and accuracy for reporting items and amounts combined was measured in terms of total inaccuracy. The ratio of the estimated weight of food consumed with the actual weight consumed was calculated along with the limits of agreement using the method of Bland and Altman. RESULTS: Comparison of PAC24 against observations at the food level resulted in values of 67.0% for matches, 11.5% for intrusions and 21.5% for omissions. The mean for total inaccuracy was 3.44 servings. For amounts, accuracy was high for matches (-0.17 and 0.23 servings for arithmetic and absolute differences, respectively) and lower for omissions (0.61 servings) and intrusions (0.55 servings). PAC24 was found to under-estimate the weight of food on average by 32% of actual intake. CONCLUSIONS: PAC24 is a lower-burden procedure for both respondents and researchers and, with slight modification, comprises a promising method for assessing diet among children.

Qualitative analysis of the contributions of nutritionists to the development of an online instrument for monitoring the food intake of schoolchildren.

BACKGROUND: The Consumo Alimentar e Atividade Fisica de Escolares (CAAFE) questionnaire is an online research tool that has been developed to enable the self-report of physical activity and diet by Brazilian schoolchildren aged 7-10 years. Formative research was conducted with nutritionists during the development of the web-based questionnaire. The suggestions and insights obtained were used to design a tool to monitor schoolchildren's food consumption based on the concept of healthy and unhealthy food indicators. The present study aimed to report the focus group discussions conducted with nutritionists concerning the CAAFE questionnaire. METHODS: Focus group discussions were conducted using a semi-structured questionnaire, and these were then analysed thematically. RESULTS: Twenty-four nutritionists participated (four focus groups; average per group: six people); the majority (n = 22) had experience with 7-10-year-old children. Four themes emerged: (i) healthy and unhealthy food indicators; (ii) suggestions for the online instrument; (iii) potential applications; and (iv) challenges for its construction. CONCLUSIONS: Comments made by nutritionists enabled the construction of an instrument that is able to answer questions related to food consumption in schools and at home.

How to engage children in self-administered dietary assessment programmes.

Effectively assessing children's dietary intake is essential for understanding the complex relationships among dietary behaviours and obesity. Dietary assessment accuracy decreases when children are unable or unmotivated to complete accurate self-reports. Technology-based assessment instruments for children's self-report of diet can be enhanced in light of developments in media psychology and communication science. To motivate children to complete a dietary assessment, researchers could use animated, customisable agents; embed the assessment process into a video game; or add narratives to encourage self-reporting behaviour. To improve accuracy, the intake environment could be recreated virtually; training sessions could be interspersed to improve portion estimation; and implicit attitudinal measures could be incorporated as a control or to increase validity. Research is needed to evaluate possible methods of enhancing children's self-reporting motivation and accuracy. The main challenge remains how to engage children without biasing their reporting.

Food Intake Recording Software System, version 4 (FIRSSt4): a self-completed 24-h dietary recall for children.

The Food Intake Recording Software System, version 4 (firsst4), is a web-based 24-h dietary recall (24 hdr) self-administered by children based on the Automated Self-Administered 24-h recall (ASA24) (a self-administered 24 hdr for adults). The food choices in firsst4 are abbreviated to include only those reported by children in US national surveys; and detailed food probe questions are simplified to exclude those that children could not be expected to answer (e.g. questions regarding food preparation and added fats). ASA24 and firsst4 incorporate 10 000+ food images, with up to eight images per food, to assist in portion size estimation. We review the formative research conducted during the development of firsst4. When completed, firsst4 will be hosted and maintained for investigator use on the National Cancer Institute's ASA24 website.

Longitudinal associations between BMI, waist circumference, and cardiometabolic risk in US youth: monitoring implications.

OBJECTIVE: This study examined whether change in body mass index (BMI) or waist circumference (WC) is associated with change in cardiometabolic risk factors and differences between cardiovascular disease specific and diabetes specific risk factors among adolescents. We also sought to examine any differences by gender or baseline body mass status. DESIGN: The article is a longitudinal analysis of pre- and post-data collected in the HEALTHY trial. Participants were 4,603 ethnically diverse adolescents who provided complete data at 6th and 8th grade assessments. METHODS: The main outcome measures were percent change in the following cardiometabolic risk factors: fasting triglycerides, systolic and diastolic blood pressure, high density lipoprotein cholesterol, and glucose as well as a clustered metabolic risk score. Main exposures were change in BMI or WC z-score. Models were run stratified by gender; secondary models were additionally stratified by baseline BMI group (normal, overweight, or obese). RESULTS: Analysis showed that when cardiometabolic risk factors were treated as continuous variables, there was strong evidence (P < 0.001) that change in BMI z-score was associated with change in the majority of the cardiovascular risk factors, except fasting glucose and the combined risk factor score for both boys and girls. There was some evidence that change in WC z-score was associated with some cardiovascular risk factors, but change in WC z-score was consistently associated with changes in fasting glucose. CONCLUSIONS: In conclusion, routine monitoring of BMI should be continued by health professionals, but additional information on disease risk may be provided by assessing WC.

Feasibility of an obesity intervention for paediatric primary care targeting parenting and children: Helping HAND.

BACKGROUND: The primary care setting offers the opportunity to reach children and parents to encourage healthy lifestyle behaviours, and improve weight status among children. OBJECTIVE: Test the feasibility of Helping HAND (Healthy Activity and Nutrition Directions), an obesity intervention for 5- to 8-year-old children in primary care clinics. METHODS: A randomized controlled pilot study of Helping HAND, a 6-month intervention, targeted children with body mass index 85-99%tile and their parents. Intervention group attended monthly sessions and self-selected child behaviours and parenting practices to change. Control group received regular paediatric care and was wait-listed for Helping HAND. Session completion, participant satisfaction, child anthropometrics, dietary intake, physical activity, TV viewing and behaviour-specific parenting practices were measured pre and post intervention. RESULTS: Forty parent-child dyads enrolled: 82.5% were Hispanic, 80% had a girl and 65% reported income ≤ $30, 000/year. There was 20% attrition from Helping HAND (attended <4/6 sessions). Families self-selected 4.35 (SD 1.75) behaviours to target during the 6-month programme and each of the seven behaviours was selected by 45-80% of the families. There were no between group differences in the child's body mass index z-score, dietary intake or physical activity post intervention. Intervention group viewed 14.9 (SE 2.3) h/week of TV post intervention versus control group 23.3 (SE 2.4) h/week (P < 0.05). CONCLUSION: Helping HAND is feasible, due to low attrition, good programme attendance, and clinically relevant improvements in some child and parenting behaviours.

Relationship of fruit and vegetable intake with adiposity: a systematic review.

UNLABELLED: Fruit and vegetable (FV) intake has been proposed to protect against obesity. The purpose of this paper was to assess the FV consumption to adiposity relationship. Twenty-three publications were included. INCLUSION CRITERIA: longitudinal or experimental designs; FV intake tested in relation to adiposity; child, adolescent or adult participants; published in English-language peer-reviewed journals. EXCLUSION CRITERIA: dietary pattern and cross-sectional designs; participants with health concerns. Experimental studies found increased FV consumption (in conjunction with other behaviours) contributed to reduced adiposity among overweight or obese adults, but no association was shown among children. Longitudinal studies among overweight adults found greater F and/or V consumption was associated with slower weight gain, but only half of child longitudinal studies found a significant inverse association. Limitations in methods prevented a thorough examination of the role of increased FV intake alone or mechanisms of effect. An inverse relationship between FV intake and adiposity among overweight adults appears weak; this relationship among children is unclear. Research needs to clarify the nature of, and mechanisms for, the effects of FV consumption on adiposity. Whether increases in FV intake in isolation from lower caloric intake or increased physical activity will result in declines or slower growth in adiposity remains unclear.

Serum levels of the adipokine fasting-induced adipose factor/angiopoietin-like protein 4 depend on renal function.

Fasting-induced adipose factor/angiopoietin-like protein 4 (FIAF/Angptl4) was recently introduced as a novel adipokine influencing glucose and lipid homeostasis. In the current study, we quantified circulating FIAF/Angtl4 levels in patients on chronic hemodialysis (CD) as compared to controls with a glomerular filtration rate above 50 ml/min. FIAF/Angptl4 was determined by ELISA in control (n=60) and CD (n=60) patients and correlated to clinical and biochemical measures of renal function, glucose and lipid metabolism, as well as inflammation, in both groups. Median serum FIAF/Angptl4 levels were more than 5-fold higher in CD patients (48.3 µg/l) as compared to control subjects (8.4 µg/l) (p<0.001). Furthermore, serum creatinine independently predicted FIAF/Angptl4 concentrations in multiple regression analyses in control subjects (p<0.01). In CD patients, C-reactive protein was independently and positively associated with circulating FIAF/Angptl4 (p<0.01). Taken together, we show that serum FIAF/Angptl4 levels are significantly increased in end-stage renal disease and independently associated with markers of renal function in control subjects.

Presence of diabetes risk factors in a large U.S. eighth-grade cohort.

OBJECTIVE: The study was conducted in 12 middle schools to determine the prevalence of diabetes, pre-diabetes, and diabetes risk factors in eighth-grade students who were predominantly minority and evaluate the feasibility of collecting physical and laboratory data in schools. RESEARCH DESIGN AND METHODS: Anthropometric measurements and fasting and 2-h post-glucose load blood draws were obtained from approximately 1,740 eighth-grade students. RESULTS: Mean recruitment rate was 50% per school, 49% had BMI > or = 85th percentile, 40.5% had fasting glucose > or = 100 mg/dl, 0.4% had fasting glucose > or = 126 mg/dl, and 2.0% had 2-h glucose > or = 140 mg/dl and 0.1% > or = 200 mg/dl. Mean fasting insulin value was 30.1 microU/ml, 36.2% had fasting insulin > or = 30 microU/ml, and 2-h mean insulin was 102.1 microU/ml. Fasting and 2-h glucose and insulin values increased across BMI percentiles, and fasting glucose was highest in Hispanic and Native American students. CONCLUSIONS: There was a high prevalence of risk factors for diabetes, including impaired fasting glucose (> or =100 mg/dl), hyperinsulinism suggestive of insulin resistance (fasting insulin > or = 30 microU/ml), and BMI > or = 85th percentile. These data suggest that middle schools are appropriate targets for population-based efforts to decrease overweight and diabetes risk.

BMI from 3-6 y of age is predicted by TV viewing and physical activity, not diet.

OBJECTIVE: To investigate whether, diet, physical activity, sedentary behavior or television (TV) viewing predicted body mass index (BMI) among 3-7-y-old children. DESIGN: A triethnic cohort of 3-4-y-old children was followed for 3 y from 1986 to 1989. MEASUREMENTS: BMI was assessed at the beginning and end of each measurement year. Heart rate monitoring and observation were used to assess physical activity. Diet (calories, % calories from fat and carbohydrate), sedentary behavior and TV viewing were assessed by direct observation in each year. A repeated measures regression analysis with year as a factor and BMI at the end of each year as dependent variables was run. Nonsignificant variables were removed in a stepwise backward deletion process and significant interactions graphed. RESULTS: The interactions between minutes of TV viewing per hour and study year and minutes of physical activity per hour and study year were significant (P<0.05). There were also significant main effects for TV viewing, physical activity and BMI from the beginning of the study. The model accounted for 65% of the variance in BMI across the three study years. Plotting the significant interactions demonstrated that physical activity was positively associated with BMI in year 1, and negatively associated in years 2 and 3 with a stronger negative relationship in year 3 than 2. TV viewing became positively associated with BMI during the third study year. CONCLUSION: Physical activity and TV viewing were the only significant predictors (other than baseline BMI) of BMI among a triethnic cohort of 3-4-y-old children followed for 3 y with both physical activity (negatively associated) and TV viewing (positively associated) becoming stronger predictors as the children aged. It appears that 6 or 7 y is a critical age when TV viewing and physical activity may affect BMI. Therefore, focusing on reducing time spent watching television and increasing time spent in physical activity may be successful means of preventing obesity among this age group.

A motivational interviewing intervention to increase fruit and vegetable intake through Black churches: results of the Eat for Life trial.

OBJECTIVES: This study reports on Eat for Life, a multicomponent intervention to increase fruit and vegetable consumption among African Americans that was delivered through Black churches. METHODS: Fourteen churches were randomly assigned to 3 treatment conditions: (1) comparison, (2) self-help intervention with 1 telephone cue call, and (3) self-help with 1 cue call and 3 counseling calls. The telephone counseling in group 3 was based on motivational interviewing. The primary outcome, assessed at baseline and 1-year follow-up, was fruit and vegetable intake as assessed by 3 food frequency questionnaires. RESULTS: Change in fruit and vegetable intake was significantly greater in the motivational interviewing group than in the comparison and self-help groups. The net difference between the motivational interviewing and comparison groups was 1.38, 1.03, and 1.21 servings of fruits and vegetables per day for the 2-item, 7-item, and 36-item food frequency questionnaires, respectively. The net difference between the motivational interviewing and self-help groups was 1.14, 1.10, and 0.97 servings for the 2-item, 7-item, and 36-item food frequency questionnaires, respectively. CONCLUSIONS: Motivational interviewing appears to be a promising strategy for modifying dietary behavior, and Black churches are an excellent setting to implement and evaluate health promotion programs.

A 7-item versus 31-item food frequency questionnaire for measuring fruit, juice, and vegetable intake among a predominantly African-American population.

OBJECTIVE: This study sought to determine which of 2 fruit and vegetable food frequency questionnaires (FFQs) most closely approximated intake measured by the average of four 24-hour dietary recalls. DESIGN: Participants completed either a 31-item FFQ (n = 70) or 7-item FFQ (n = 76) on 2 occasions approximately 2 weeks apart. During the interval between FFQs1 participants provided four 24-hour dietary recalls via telephone interview. SUBJECTS/SETTING: Participants were 146 persons with food preparation responsibilities in families of students in grades 3 through 5. Respondents were predominantly African-American women in Atlanta, Ga. STATISTICAL ANALYSIS: Pearson correlation coefficients of log-transformed values estimated the reliability of each FFQ and compared FFQ estimates to reference values. The intraclass correlation coefficient evaluated consistency across 24-hour recalls. RESULTS: The first FFQs overestimated intake approximately twofold. The 31-item FFQ estimates exceeded 7-item FFQ estimates by approximately 30% . Correlations with recall estimates were high for the 7-item FFQ and moderate to low for the 31-item FFQ. The second FFQ estimates were more highly correlated to reference values. From the first to the second administration, 7-item FFQ estimates dropped from 5.2 to 2.7 servings, and 31-item FFQ estimates dropped from 6.7 to 3.5 servings. Neither FFQ produced highly reliable estimates. CONCLUSIONS: Mean total fruit and vegetable consumption was closer to reference estimates for the first 7-item FFQ and the second 31-item FFQ. The 7-item FFQ correlated more highly with reference estimates than did the 31-item FFQ. Therefore, we conclude that for African-American adults, a 1-time-administered FFQ using 7 broad food categories correlates more highly with reference values than a FFQ using 31 individual fruit and vegetable items.

Family and child-care provider influences on preschool children's fruit, juice, and vegetable consumption.

Children's intakes of fruit, juice, and vegetables (FJV) do not meet the recommended minimum of five daily servings, placing them at increased risk for development of cancer and other diseases. Because children's food preferences and practices are initiated early in life (e.g., 2-5 years of age), early dietary intervention programs may have immediate nutritional benefit, as well as reduce chronic disease risk when learned healthful habits and preferences are carried into adulthood. Families and child-care settings are important social environments within which food-related behaviors among young children are developed. FJV preferences, the primary predictor of FJV consumption in children, are influenced by availability, variety, and repeated exposure. Caregivers (parents and child-care providers) can influence children's eating practices by controlling availability and accessibility of foods, meal structure, food modeling, food socialization practices, and food-related parenting style. Much remains to be learned about how these influences and practices affect the development of FJV preferences and consumption early in life.