Biomedical subjects

Leonard H Epstein

Publications and source records attributed to Leonard H Epstein.

At least 19 recordsLinked to original sources

PubMed2006

Relationship between parental estimate and an objective measure of child television watching.

Many young children have televisions in their bedrooms, which may influence the relationship between parental estimate and objective measures of child television usage/week. Parental estimates of child television time of eighty 4-7 year old children (6.0 +/- 1.2 years) at the 75th BMI percentile or greater (90.8 +/- 6.8 BMI percentile) were compared to an objective measure of television time obtained from TV Allowance devices attached to every television in the home over a three week period. Results showed that parents overestimate their child's television time compared to an objective measure when no television is present in the bedroom by 4 hours/week (25.4 +/- 11.5 vs. 21.4 +/- 9.1) in comparison to underestimating television time by over 3 hours/week (26.5 +/- 17.2 vs. 29.8 +/- 14.4) when the child has a television in their bedroom (p = 0.02). Children with a television in their bedroom spend more objectively measured hours in television time than children without a television in their bedroom (29.8 +/- 14.2 versus 21.4 +/- 9.1, p = 0.003). Research on child television watching should take into account television watching in bedrooms, since it may not be adequately assessed by parental estimates.

Journal Article↗

PubMed2006

Association of access to parks and recreational facilities with the physical activity of young children.

OBJECTIVE: To determine associations of the neighborhood and home television environments with young children's physical activity. METHOD: 32 boys and 27 girls age 4 to 7 years wore accelerometers for 3 weekdays and 1 weekend day. The number of televisions in the home and television watching of the child were monitored using TV Allowance units for 3 weeks. A geographic information system was used to measure neighborhood environment variables. RESULTS: Hierarchical regression analysis was used to predict physical activity, initially controlling for sex, age, socioeconomic status, adiposity, and child television watching in step 1. In step 2, the number of televisions did not significantly increase the amount of variability accounted for in the prediction of physical activity. In step 3, housing density and the interaction of housing density by sex accounted for an incremental 12% (p < 0.05) of the variability and in step 4 percentage park plus recreation area accounted for a further 10% (p < 0.05) of the variability. Greater housing density predicted increased physical activity of boys, but not girls. CONCLUSION: Neighborhoods with increased proximity between homes and a greater proportion of park area are associated with greater physical activity in young children.

Body Mass Index↗

PubMed2006

Relationship of mother and child food purchases as a function of price: a pilot study.

To our knowledge, there are no data on parental influences on child purchasing behavior of healthy or unhealthy foods. Mothers and children in ten families were given 5.00 US dollars to purchase portions of preferred fruits/vegetables and high energy-dense snack foods for each of ten trials of price manipulations. For five of the trials the price of the fruit/vegetable increased in price from 0.50 US dollars to 2.50 US dollars (in 0.50 US dollar increments), while the price of the energy-dense snack food remained constant at 1.00 US dollar. For the remaining five trials, the commodity that previously rose in price remained constant at 1.00 US dollars and the other commodity varied from 0.50 US dollars to 2.50 US dollars. Same-price elasticity was shown for both the child and parent purchases, and parent purchases were significantly related to child purchases of both healthy (regression estimate = 0.46, p < 0.001) and unhealthy (regression estimate = 0.12, p = 0.036) foods. Children's purchases of unhealthy snack food items were positively related to family socioeconomic status, and negatively related to child age. These results indicate that parental food choice and purchasing behaviors may play a role in the development of children's purchasing of both healthy and unhealthy foods.

Adult↗

PubMed2006

Habituation and recovery of salivation and motivated responding for food in children.

Salivary responses habituate to repeated presentations of food cues, and these responses recover when new food stimuli are presented. Research suggests that within-session changes in motivated responding for food may also habituate, and motivated responding may, therefore, recover when new foods are presented. The purpose of this study was to evaluate similarities in the pattern of salivation and motivated responding for a cheeseburger stimulus in children, followed by either a novel stimulus (French fries) or another cheeseburger trial. The order of the task (salivation or motivation) was counterbalanced over days. Salivation and motivated responding for cheeseburger were reliably reduced over seven trials, and responses recovered after presentation of French fries on trial 8. Random regression models showed a significant relationship between the rate of change in motivated responding and salivation. These results provide additional support for similarities in processes that regulate salivation and motivated responding for food and strengthen support for the hypothesis that changes in motivated responding can be understood by habituation theory.

Child↗

PubMed2006

Role of functional genetic variation in the dopamine D2 receptor (DRD2) in response to bupropion and nicotine replacement therapy for tobacco dependence: results of two randomized clinical trials.

Although bupropion and nicotine replacement therapy (NRT) are efficacious tobacco dependence treatments, there is substantial interindividual variability in therapeutic response and most smokers relapse. Pharmacogenetics research may improve treatment outcomes by identifying genetic variants predictive of therapeutic response. We investigated the roles of two functional genetic variants in the dopamine D2 receptor (DRD2) gene in response to pharmacotherapy for tobacco dependence among participants in two randomized clinical trials with a 6-month follow-up period: a double-blind placebo-controlled trial of bupropion (n=414) and an open label trial of transdermal nicotine vs nicotine nasal spray (n=368). At the end of the treatment phase, a statistically significant (p=0.01) interaction between the DRD2 - 141C Ins/Del genotype and treatment indicated a more favorable response to bupropion among smokers homozygous for the Ins C allele compared to those carrying a Del C allele. By contrast, smokers carrying the Del C allele had statistically significantly (p=0.006) higher quit rates on NRT compared to those homozygous for the Ins C allele, independent of NRT type. The C957T variant was also associated (p=0.03) with abstinence following NRT. These results suggest that bupropion may be the preferred pharmacologic treatment for smokers homozygous for the DRD2 - 141 Ins C allele, while NRT may be more beneficial for those who carry the Del C allele. Study findings require confirmation in additional larger samples before they are applied in practice.

Administration, Intranasal↗

PubMed2006

Purchases of food in youth. Influence of price and income.

One way to increase choice of healthy over unhealthy behaviors is to increase the cost of less healthy alternatives or reduce the cost of healthier alternatives. The influence of price on purchases of healthy and unhealthy foods was evaluated in two laboratory experiments. In Experiment 1, thirty-two 10- to 12-year-old youth were given $5.00 and allowed to purchase multiple portions of a healthy food (fruit or vegetable) and a less healthy food (higher-fat snack). The price of one type of food varied from $0.50 to $2.50, while the price of the other type was held at $1.00. Increasing the price of a type of food reduced purchases of that type of food, but did not lead to substitution with the alternative type of food. In Experiment 2, twenty 10- to 14-year-old youth were given $1.00, $3.00, and $5.00 to purchase healthy and unhealthy foods. The price of each food was raised and lowered by 25% and 50%. Raising the price of healthy or unhealthy foods resulted in decreased purchases of those foods, and income available interacted with price to predict the pattern of substitution of alternative foods. These results show the potential for controlled laboratory studies of price and food purchases, and show that the substitution of healthier for unhealthy food is related to available money.

Child↗

PubMed2006

Reducing sedentary behavior: the relationship between park area and the physical activity of youth.

This study was designed to determine whether the characteristics of the neighborhood environment are related to the substitution of physical activity for sedentary behavior among youth. Fifty-eight 8- to 15-year-old youth were studied in a within-subjects crossover design with three phases: baseline, increased sedentary behavior, and decreased sedentary behavior. The relations between changes in physical activity and design, diversity, and density attributes of the neighborhood environment were determined using random coefficient models. Compared with girls, boys showed greater increases in physical activity when sedentary behaviors were reduced and greater decreases in physical activity when sedentary behaviors were increased. Greater access to parks was associated with greater physical activity when sedentary behaviors were reduced.

Adolescent↗

PubMed2006

Validity of PCERT and OMNI walk/run ratings of perceived exertion.

PURPOSE: This study was conducted to test the validity of the Pictorial Children's Effort Rating Table (PCERT) and OMNI walk/run scales. METHODS: Children (26 boys age 11.2 yr +/- 1.6 and 25 girls age 11.1 yr +/- 1.4) performed a five-stage incremental exertion treadmill test. The undifferentiated perceived exertion from the PCERT and OMNI scales was assessed for construct validity using Pearson correlations with VO(2) and heart rate as criteria and concurrent validity by correlating PCERT and OMNI scores. RESULTS: Increases in PCERT and OMNI scale scores were correlated with increases in VO(2) (r = 0.90 and 0.92) and heart rate (r = 0.89 and 0.92). No difference was found in slope of the PCERT and OMNI scores when regressed against heart rate or VO(2) and the slopes were invariant across sexes. To test concurrent validity of the PCERT and OMNI scales, subject scores at each stage were converted to a percentage of the maximal scale. No effect of sex was noted on perceived exertion (P = 0.32), and the percentage of the maximal PCERT and OMNI scales was almost identical at each stage (P = 0.73). CONCLUSIONS: Validity of both the PCERT and OMNI scales was established for submaximal exercise. PCERT and OMNI scores are not interchangeable because they have different scales, but at a given exercise intensity youth assign similar percentages of the maximal scores.

Child↗

PubMed2006

The relationship between motor proficiency and physical activity in children.

OBJECTIVES: Youth with better motor abilities may find it easier to be physically active and may be more likely to engage in physical activity compared with peers with poorer motor competence. The purpose of this study was to examine the relationship between motor proficiency and physical activity in 8- to 10-year-old children. Self-efficacy toward physical activity was also assessed. METHODS: Sixty-five children (34 girls and 31 boys) were studied. Children's physical activity was assessed by the Manufacturing Technologies Incorporated/Computer Science and Applications Incorporated model 7164 accelerometer, and their motor proficiency was determined by the Bruininks-Oseretsky Test of Motor Proficiency. The Children's Self-Perceptions of Adequacy in and Predilection for Physical Activity scale measured children's self-perceptions of adequacy in performing and desire to participate in physical activities. RESULTS: Children's motor proficiency was positively associated with activity counts and percentage of time in moderate and moderate-to-vigorous intensity physical activity and inversely related to percentage of time in sedentary activity. Children in the greatest quartile of motor proficiency were the most physically active compared with children with lower levels of motor proficiency who had similar levels of physical activity. Children with greater standardized BMI were less physically active, more sedentary, and had poorer motor proficiency compared with children with a lower standardized BMI. Children's Self-Perceptions of Adequacy in and Predilection for Physical Activity scores were positively associated with Bruininks-Oseretsky Test of Motor Proficiency standard score for boys. Children's motor proficiency explained an additional 8.7% of the variance in physical activity in multiple linear regression after controlling for factors that may influence physical activity. CONCLUSIONS: Motor proficiency is positively associated with physical activity and inversely associated with sedentary activity in children, but there may be a threshold of motor proficiency above which children may be the most physically active. Children's motor proficiency may be an appropriate target for increasing physical activity in youth.

Child↗

PubMed2005

Food reinforcement.

The reinforcing value of food, measured by how hard someone is willing to work to obtain food, is influenced by food palatability, food deprivation and food variety, and may be a more powerful determinant of food intake than hedonics or liking. The reinforcing value of food is mediated in part by dopaminergic activity. Genotypes that influence dopamine transport and the density of dopamine D2 receptors interact with food reinforcement to influence eating behavior, and D2 receptor genotypes may influence food reinforcement and weight gain after smoking cessation. Inhibition of dopamine transport increases brain dopamine concentrations, which may influence weight gain after smoking cessation and can reduce energy intake in obese adults.

Dopamine↗

PubMed2005

Effects of allocation of attention on habituation to olfactory and visual food stimuli in children.

Responding to food cues may be disrupted by allocating attention to other tasks. We report two experiments examining the effects of allocation of attention on salivary habituation to olfactory plus visual food cues in 8-12-year-old children. In Experiment 1, 42 children were presented with a series of 8 hamburger food stimulus presentations. During each intertrial interval, participants completed a controlled (hard), or automatic (easy) visual memory task, or no task (control). In Experiment 2, 22 children were presented with 10 presentations of a pizza food stimulus and either listened to an audiobook or no audiobook control. Results of Experiment 1 showed group differences in rate of change in salivation (p=0.014). Children in the controlled task did not habituate to repeated food cues, while children in the automatic (p<0.005) or no task (p<0.001) groups decreased responding over time. In Experiment 2, groups differed in the rate of change in salivation (p=0.004). Children in the no audiobook group habituated (p<0.001), while children in the audiobook group did not habituate. Changes in the rate of habituation when attending to non-food stimuli while eating may be a mechanism for increasing energy intake.

Attention↗

PubMed2005

The relationship between parent and child self-reported adherence and weight loss.

OBJECTIVE: Better adherence to treatment strategies in family-based behavioral weight control programs may lead to greater weight reduction and improved weight maintenance in youth. This study assessed the influence of child and parent self-reported adherence to behavioral strategies on changes in 2-year child and parent percentage overweight. RESEARCH METHODS AND PROCEDURES: Participants included 8- to 12-year-old children in >or= 85th BMI percentile and their parents from 110 families taking part in two family-based randomized controlled weight control studies. This study examined whether self-reported adherence to behavioral strategies measured at 24 months increased prediction of child and parent percentage overweight change through 24-month follow-up after accounting for other factors that may influence weight change. RESULTS: Child adherence to weighing and to preplanning for celebrations where high-fat foods are served and parent adherence to praising the child and modeling healthy eating habits predicted 24-month child percentage overweight change (p<0.001). Child adherence to recording food and calories and parent adherence to modeling healthy eating habits predicted 24-month parent percentage overweight change (p<0.001). In hierarchical regression models, child weighing and preplanning and parent modeling were significant (p<0.01) incremental predictors (r2 of 24.8%) of 24-month child percentage overweight. Child recording and parent modeling were significant (p<0.01) incremental predictors (r2 of 14%) of parent 24-month percentage overweight change. DISCUSSION: Child and parent adherence to specific components of family-based behavioral weight control treatment are independent predictors of long-term child and parent percentage overweight change.

Adult↗

PubMed2005

The influence of parenting change on pediatric weight control.

OBJECTIVE: Parenting style was examined as a predictor of weight loss maintenance in behavioral family-based pediatric obesity treatment. RESEARCH METHODS AND PROCEDURES: Fifty obese children who participated in a behavioral family-based pediatric obesity treatment were studied. Hierarchical regression tested the incremental effect of baseline parenting and parenting during treatment on children's percentage overweight change over 12 months, beyond demographics and adherence to targeted behaviors. RESULTS: Children's percentage overweight significantly decreased at 6 (-16.3) and 12 (-11.1) months. Adherence to program goals significantly increased variance accounted for in the regression model by 10.8%, whereas adding baseline father acceptance and change in father acceptance accounted for another 20.5%. The overall model accounted for 40.6% of the variance in pediatric weight control. ANOVA showed significantly greater percentage overweight decrease from baseline for youth with fathers who increased their acceptance vs. those who decreased acceptance at 6 (-19.8 vs. -14.6) and 12 (-17.4 vs. -8.1) months. DISCUSSION: Youth who perceive an increase in father acceptance after treatment had better changes in percentage overweight over 12 months than youth with lower ratings of father acceptance. Future directions include examining how other parenting dimensions impact pediatric obesity treatment outcome and how parental acceptance can be enhanced to improve child weight control.

Attitude to Health↗

PubMed2005

Recurrent event analysis of lapse and recovery in a smoking cessation clinical trial using bupropion.

We report a reanalysis of data from a prior study describing the event history of quitting smoking aided by bupropion, using recurrent-event models to determine the effect of the drug on occurrence of lapses and recoveries from lapse (resumption of abstinence). Data were collected on 1,070 subjects across two similar double-blind randomized clinical trials of bupropion versus placebo and fitted with separate Cox regression models for lapse and recovery. Analyses were split using discrete time-varying covariates between the treatment (weeks 1-10) and follow-up phases (end of treatment to 12 months). Bupropion was associated with slower lapse during treatment for both sexes, and being female was associated with faster lapse across both phases. Drug did not affect time to recovery for males but was associated with faster recovery among females, allowing women to recover as quickly as men. High levels of nicotine dependence did not affect time to lapse but were associated with slower recovery from lapse across treatment and follow-up phases. During the treatment phase, higher levels of baseline depression symptoms had no effect on time to lapse but were associated with slower recovery from lapse. Results highlight the asymmetry in factors preventing lapse versus promoting recovery. Specifically, dependence, depression symptoms, and a sex x drug interaction were found to affect recovery but not lapse. Further research disentangling lapse and recovery events from summary abstinence measures is needed to help us develop interventions that take advantage of bupropion at its best and that compensate where it is weak.

Adult↗

PubMed2005

Influence of changes in sedentary behavior on energy and macronutrient intake in youth.

BACKGROUND: Changes in sedentary behavior may be related to changes in energy intake. OBJECTIVE: The purpose of this study was to investigate how experimental changes in the amount of sedentary behaviors influence energy intake. DESIGN: Sixteen nonoverweight 12-16-y-old youth were studied in a within-subject crossover design with three 3-wk phases: baseline, increasing targeted sedentary behaviors by 25-50% (increase phase), and decreasing targeted sedentary behaviors by 25-50% (decrease phase). Repeated 24-h recalls were used to assess energy and macronutrient intakes during targeted sedentary behaviors. Accelerometers were used to assess activity levels. RESULTS: Targeted sedentary behaviors increased by 81.5 min/d (45.8%) and decreased by 109.8 min/d (-61.2%) from baseline (both: P<0.01). Girls increased sedentary behaviors significantly more than did boys (107.3 and 55.8 min/d, respectively; P<0.01) in the increase phase. Energy intake decreased (-463.0 kcal/d; P<0.01) when sedentary behaviors decreased: the decrease in fat intake was -295.2 kcal/d (P<0.01). No significant changes in energy intake were observed when sedentary behaviors were increased. Youth also increased their activity by 102.4 activity counts min-1d-1 (estimated at 113.1 kcal) when sedentary behaviors were decreased (P<0.05). CONCLUSIONS: Decreasing sedentary behaviors can decrease energy intake in nonoverweight adolescent youth and should be considered an important component of interventions to prevent obesity and to regulate body weight.

Adolescent↗

PubMed2005

Physical activity as a substitute for sedentary behavior in youth.

BACKGROUND: Youth may choose to be sedentary rather than physically active. PURPOSE: The purpose of this study was to use behavioral economics methods to investigate how experimental changes in the amount of sedentary behaviors influenced physical activity. METHODS: Fifty-eight 8- to 16-year-old youth were studied in a within-subject crossover design with three 3-week phases: baseline, increasing, and decreasing targeted sedentary behaviors by 25% to 50%. RESULTS: At baseline, boys were more active than girls (518.9 vs. 401.2 accelerometer counts/min, p = .02), and obese youth more sedentary than nonobese youth (240.5 vs. 174.4 min/day, p = .003). During the increase sedentary behavior phase, targeted sedentary behaviors increased by 52.1%, with girls increasing sedentary behaviors more than boys (114.7 vs. 79.8 min/day, p = .04). Physical activity decreased (-48.3 counts/min, p < .01) when sedentary behaviors increased, with obese youth decreasing total and moderate to vigorous physical activity (MVPA) more than nonobese youth (-110.4 vs. 8.9 counts/min, p < .001; -3.3 vs. -.03 % MVPA, p = .013). During the decrease sedentary behavior phase, targeted sedentary behaviors decreased by 55.6% from baseline as nonobese youth increased physical activity, whereas obese youth decreased physical activity (55.8 vs. -48.0 counts/min, p = .042; 1.1 vs. -2.1% MVPA, p = .021). Youth who substituted physical activity when sedentary behaviors were increased had greater standardized body mass index (z-body mass index = 1.4 vs. 0.4, p = .018), whereas youth who substituted physical activity when sedentary behaviors were decreased were less active at baseline (396.1 vs. 513.7 counts/min, p = .035). CONCLUSIONS: Behavioral economics provides a methodology to understand changes in physical activity when sedentary behaviors are modified and to identify factors associated with substitution of physically active for sedentary behaviors.

Activities of Daily Living↗

PubMed2005

The challenge of identifying behavioral alternatives to food: clinic and field studies.

BACKGROUND: One of the basic principles of behavioral economics interventions is identification of alternative behaviors to compete with the reinforcing value of a highly rewarding commodity. PURPOSE: Two experiments that attempt to increase alternatives to eating in obese youth are presented. METHODS: A randomized, controlled trial was used in Study 1 to compare a comprehensive family-based behavioral treatment program or an experimental treatment that incorporated reinforcing children for engaging in alternative behaviors to eating for 41 overweight 8- to 12-year-old children. Study 2 used a within-subject design with baseline, enriched environment and a second baseline phase to determine the influence of providing activities that compete with eating for 13 overweight 8- to 12-year-old children. Measurements included body mass index (BMI) change, alternatives to eating, eating, and physical activity. RESULTS: In Study 1 both treatments were associated with significant (p < .05) and maintained reductions in z-BMI over the 24 months of observation. The experimental group showed a significantly (p < .05) greater increase in alternatives to eating, and both groups showed significant (p < .05) increases in physical activity. In Study 2 alternative behaviors to eating were increased by almost 1 hr/day (p < .001) but were not associated with significant changes in energy intake or physical activity. CONCLUSION: These results suggest that using the methods studied, increasing behaviors that could compete with eating did not influence relative weight in a clinical outcome study or energy intake in a controlled field study.

Analysis of Variance↗

PubMed2004

Validation of a questionnaire measure of the relative reinforcing value of food.

The traditional method of measuring the relative reinforcing value of food provides subjects a choice of food and non-food alternatives, and defines the relative reinforcing value of food based on the allocation of responses for the two alternatives as the schedules of reinforcement for the alternatives change. Greater allocation of responses for one alternative versus another reflects the relative reinforcing value of the alternatives. This method was designed for laboratory use, but methods are needed to extend measurement of reinforcing value to applied research environments. Two experiments were conducted to assess the validity of a questionnaire measure of the relative reinforcing value of food in normal weight university samples. Study 1 (n=39) assessed the relationship between the relative reinforcing value of snack food versus fruits and vegetables (condition 1) or enjoyable sedentary behaviors (condition 2) as measured by the questionnaire and standardized computerized concurrent schedules criterion. A significant relationship (Pearson r=0.49, p<0.01; Guttman's MU2=0.69) across the two conditions between the two methods of measuring food reinforcement was observed. Experiment 2 (n=10) utilized a within-subject counterbalanced design to manipulate food deprivation and hunger levels to determine if food deprivation increased the reinforcing value of snack food as measured by the questionnaire to provide an index of validity of the questionnaire. Results showed that food deprivation increased the relative reinforcing value of snack food. Results from both studies suggest that the questionnaire has good validity, and may represent an efficient and reliable method of assessing the relative reinforcing value of food.

Adolescent↗