The reinforcing value of food and non-food alternative: Associations with BMI z-score and percent fat mass

Reducing relative food reinforcement of infants using a music enrichment program: a randomized, controlled trial

BACKGROUND

Food reinforcement or one's motivation to eat may be established early in life; it might not be the food reinforcement per se that drives weight gain, but rather the imbalance between food and nonfood reinforcement.

OBJECTIVES

We implemented a 2-y randomized, controlled trial to assess the effects of a music enrichment program (music, n = 45) compared with an active play date control (control, n = 45) in 9- to 15-mo-old healthy infants who were strongly motivated to eat.

METHODS

The 12-mo intensive intervention phase included 4 semesters of Music Together® or a play date program (Winter, Spring, Summer, and Fall), comprised of once per week group meetings, followed by a 12-mo maintenance phase with monthly meetings. Parents were encouraged to listen to the Music Together® program CD or play with the play date group's toy with their infants at home, respectively. We performed a modified intention-to-treat analysis using all randomly assigned, non-excluded subjects for the outcome measures [relative reinforcing value of food (RRVfood), food reinforcement, music reinforcement, and weight-for-length z-score (WLZ)].

RESULTS

There were significant differential group changes across time for RRVfood (group × month; P = 0.016; Cohen's f2 = 0.034). The music group had significantly greater RRVfood decreases than the control group from baseline to the end of the intensive intervention phase (music change = -0.211; control change = -0.015; P = 0.002; Cohen's D = 0.379). However, these differences were not maintained during months 12-24 (music change = -0.187; control change = -0.143; P = 0.448; D = 0.087). We observed an overall moderation effect by sex for food reinforcement and WLZ. Boys in the music group had a significant attenuation in food reinforcement and WLZ compared with boys in the control group.

CONCLUSIONS

This study extends our knowledge in infant eating behavior by providing insight into the role of nonfood alternatives in altering one's motivation to eat. There may be sex differences in altering one's motivation to eat.This trial was registered at clinicaltrials.gov as NCT02936284.

Bioelectrical impedance analysis for assessment of body composition in infants and young children-A systematic literature review

Bioelectrical impedance analysis (BIA) is an easy to use, portable tool, but the accuracy of the technique in infants and young children (<24 months) remains unclear. A systematic literature review was conducted to identify studies that have developed and validated BIA equations in this age group. MEDLINE, Scopus, EMBASE, and CENTRAL were searched for relevant literature published up until June 30, 2020, using terms related to bioelectrical impedance, body composition, and paediatrics. Two reviewers independently screened studies for eligibility, resulting in 15 studies that had developed and/or validated equations. Forty-six equations were developed and 34 validations were conducted. Most equations were developed in young infants (≤6 months), whereas only seven were developed among older infants and children (6-24 months). Most studies were identified as having a high risk of bias, and only a few included predominantly healthy children born at term. Using the best available evidence, BIA appears to predict body composition at least as well as other body composition tools; however, among younger infants BIA may provide little benefit over anthropometry-based prediction equations. Currently, none of the available equations can be recommended for use in research or in clinical practice.

The Relative Reinforcing Value of Cookies Is Higher Among Head Start Preschoolers With Obesity

The relative reinforcing value (RRV) of food measures how hard someone will work for a high-energy-dense (HED) food when an alternative reward is concurrently available. Higher RRV for HED food has been linked to obesity, yet this association has not been examined in low-income preschool-age children. Further, the development of individual differences in the RRV of food in early childhood is poorly understood. This cross-sectional study tested the hypothesis that the RRV of HED (cookies) to low-energy-dense (LED; fruit) food would be greater in children with obesity compared to children without obesity in a sample of 130 low-income 3- to 5-year-olds enrolled in Head Start classrooms in Central Pennsylvania. In addition, we examined individual differences in the RRV of food by child characteristics (i.e., age, sex, and reward sensitivity) and food security status. The RRV of food was measured on concurrent progressive-ratio schedules of reinforcement. RRV outcomes included the last schedule reached (breakpoint) for cookies (cookie Pmax) and fruit (fruit Pmax), the breakpoint for cookies in proportion to the total breakpoint for cookies and fruit combined (RRV cookie), and response rates (responses per minute). Parents completed the 18-item food security module to assess household food security status and the Behavioral Activation System scale to assess reward sensitivity. Pearson's correlations and mixed models assessed associations between continuous and discrete child characteristics with RRV outcomes, respectively. Two-way mixed effects interaction models examined age and sex as moderators of the association between RRV and Body Mass Index z-scores (BMIZ). Statistical significance was defined as p < 0.05. Children with obesity (17%) had a greater cookie Pmax [F (1, 121) = 4.95, p = 0.03], higher RRV cookie [F (1, 121) = 4.28, p = 0.04], and responded at a faster rate for cookies [F (1, 121) = 17.27, p < 0.001] compared to children without obesity. Children with higher cookie response rates had higher BMIZ (r = 0.26, p < 0.01); and RRV cookie was positively associated with BMIZ for older children (5-year-olds: t = 2.40, p = 0.02) and boys (t = 2.55, p = 0.01), but not younger children or girls. The RRV of food did not differ by household food security status. Low-income children with obesity showed greater motivation to work for cookies than fruit compared to their peers without obesity. The RRV of HED food may be an important contributor to increased weight status in boys and future research is needed to better understand developmental trajectories of the RRV of food across childhood.

Infants with big appetites: The role of a nonfood environment on infant appetitive traits linked to obesity

BACKGROUND

Individual differences in appetitive traits present in the first few weeks of life. Research has shown that infants with a greater food reinforcement ratio (FRR) have higher obesity risk. To date, limited work has examined the relation between FRR and appetitive traits of infants, and how FRR relates to appetitive traits and obesity development.

OBJECTIVES

To examine the relation between appetitive traits and food and nonfood reinforcement of infants aged 9-18 mo, and to examine whether food and nonfood reinforcement mediate the relation between appetitive traits and weight-for-length z-score (zWFL).

METHOD

This secondary data analysis was conducted by combining 4 different cohorts of infants (n = 143) who have complete data on the food/nonfood reinforcement task, Baby Eating Behavior Questionnaire, and anthropometrics and demographics assessments. Three different nonfood reinforcers were used: video (DVD; n = 27), playing with bubbles (Bubbles; n = 67), and music accompanied by instruments (Music; n = 49) for the nonfood portion of the task. For the food portion of the task, the infant's favorite food was used.

RESULTS

General appetite positively correlated with FRR and zWFL, but negatively correlated with nonfood reinforcement; satiety responsiveness negatively correlated with food reinforcement, FRR, and zWFL. Mediational analysis showed that effects of general appetite on zWFL were mediated by FRR (indirect effect = 0.100, 95% CI: 0.041, 0.187) and nonfood reinforcement (indirect effect = 0.076, 95% CI: 0.025, 0.156). We also observed the mediating effect of FRR on the relation of satiety responsiveness and zWFL (indirect effect = -0.097, 95% CI: -0.204, -0.026).

CONCLUSIONS

Our work contributes to the mechanistic understanding of the ontogeny of obesity development early in life among individuals who are born with appetitive drive for overconsumption. During early infancy, the nonfood environment may protect against this drive and prevent obesity development.

Development of a measure of the relative reinforcing value of food versus parent-child interaction for young children

The relative reinforcing value (RRV) of food captures individual differences in the motivation to eat and is associated with weight status among infants, children, and adults. Currently, there is no concurrent measure of the RRV of food versus a non-food alternative for 4-to-5-year-old children. The present study aimed to develop and validate a measure of the RRV of food versus time spent interacting with a parent in the context of reading among 4-to-5-year-old children. The first phase of the study involved an online survey. Parents of 4-to-5 year olds (n = 102) reported their children's consumption frequency and liking for thirty-six snack foods. A priori criteria were used to identify snacks that were well-liked and served at least sometimes for use in the subsequent laboratory study. Then, a validation study was conducted in the laboratory to examine the construct validity of the finalized RRV task. Thirty-one parent-child dyads completed a laboratory visit, in which children's RRV of food versus time spent reading with a parent was measured concurrently on a progressive ratio reward schedule. Linear regression was used to assess validity of the task. Children's RRV of food positively and significantly predicted BMI z-scores among children with complete data (B = 0.41, p < 0.05, n = 28). Maximum schedules reached for food also positively and significantly predicted BMI z-scores (B = 0.30, p < 0.05). The relationship between maximum schedules reached for parent-child reading and BMI z-scores was in the expected direction, but this relationship was non-significant. Results support the validity and feasibility of the RRV paradigm used in the present study. Future research could continue to examine the measurement properties of this paradigm, as well as the potential for positive parent-child interactions to serve as a novel alternative to food.