Repeatability of the infant food reinforcement paradigm: Implications of individual and developmental differences

Examining links between child temperament and feeding, eating, and weight outcomes: An updated systematic review of the literature

BACKGROUND

Weight outcomes have been associated with child temperament, defined as individual differences in reactivity and self-regulation. The current systematic review aims to provide an updated summary of the evidence linking temperamental negative reactivity, surgency, and regulation superfactors to early childhood feeding, eating, and weight outcomes.

METHODS

PubMed, PsycINFO and Embase databases, as well as scientific meeting programs, were searched using keywords and subject headings. Publication dates were limited to 2012-2019 as prior reviews were published in 2012 and 2014. Identified studies were eligible if they included children ages 0-5 years, a measure of child temperament, and a measure of parent/caregiver feeding, child eating, or child weight. 7113 studies were identified and 121 met inclusion criteria.

RESULTS

Feeding, eating, and weight outcomes were largely unrelated to overarching negative reactivity, surgency, and effortful control superfactors. Examination of individual temperament dimensions suggested difficult temperament was frequently linked to non-responsive feeding practices, whereas elevated emotionality and decreased self-regulation were linked to maladaptive eating behaviors, and lower inhibitory control to adiposity. Analyses with infants reported greater percentages of significant associations compared to children, and cross-sectional studies generally reported fewer significant associations than other study designs.

CONCLUSIONS

Difficult temperament, greater emotionality and lower self-regulation and inhibitory control were the aspects of temperament most consistently related to poorer early childhood feeding, eating, and weight outcomes. Associations tended to be stronger in infancy, and when examined within a non-cross-sectional study design. Findings can inform the development of tailored efforts to promote healthy eating and growth throughout childhood.

SmartMoms Canada: An evaluation of a mobile app intervention to support a healthy pregnancy

BACKGROUND

There is a lack of cost-effective and readily available access to evidence-based information to manage healthy behaviours for pregnant individuals. Mobile health (mHealth) tools offer a cost-effective, interactive, personalized option that can be delivered anywhere at a time most convenient for the user. This study protocol was primarily developed to, i) assess the feasibility of the SmartMoms Canada intervention in supporting participants to achieve gestational weight gain (GWG) guidelines. The secondary objectives are to, ii) assess user experience with the app, measured by adherence to the program via app software metrics and frequency of use, iii) determine the impact of SmartMoms Canada app usage on the adoption of healthful behaviours related to nutrition, physical activity and sleep habits, improvements in health-related quality of life, pregnancy-related complications, and symptoms of depression, and iv) investigate the potential extended effects of the app on postpartum health-related outcomes.

METHODS

This is a feasibility trial. Pregnant individuals aged 18-40 years with pre-gravid body mass index between 18.5 and 39.9 kg/m², carrying a singleton fetus, having Wi-Fi access, and at ≤20 weeks' gestation will be recruited. Eligible people will be followed from recruitment until 12 months postpartum.

DISCUSSION

SmartMoms Canada is the first bilingual Canadian-centric app designed for pregnant people. This mHealth intervention, with its ability to supply frequent interactions, provides pregnancy- related health knowledge to users, potentially leading to an improvement in pregnancy-related outcomes and behaviours, and, ultimately a reduction in the present economic burden related to in-person interventions.

TRIAL REGISTRATION

ISRCTN, ISRCTN16254958. Registered 20 December 2019, http://www.isrctn.com/ ISRCTN16254958.

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.

Infant Distress in a Food Delay Task Changes With Development and Predicts Amount Consumed

Objective

Eating behavior regulation emerges during early development and involves general self-regulation (emotional, behavioral), appetite regulation (homeostatic metabolic need) and appetite self-regulation (including both Bottom-Up Food Approach and Bottom-Up Food Avoidance and top-down purposeful self-control of eating). Limited research has investigated developmental trajectories of the regulation of eating behavior before the preschool years. The current study used a novel food delay task to assess infant distress as an early emerging marker of eating behavior regulation constructs across early infancy and examine associations with amount of milk consumed.

Method

Mother-infant dyads (n = 179) completed the Ability to Delay Gratification for Food in Infants Task (ATDG-FIT) at 2 weeks, 8 weeks, and 16 weeks of age. The ATDG-FIT required infants to wait before being fed while their bottle was present, but not accessible (3-min Pre-Feeding Delay). After this, the infant was fed for 1 min, then the feeding was paused for 30 s (Mid-Feeding Delay). Infant distress was coded during each feeding delay period and the amount of milk consumed was measured.

Results

The mean proportion of distress during the Pre-Feeding Delay period decreased from 8 to 16 weeks of age (F(2,230) = 15.02, p < 0.001), whereas the mean proportion of distress during the Mid-Feeding Delay increased from 2 to 8 weeks of age (F(2,230) = 27.04, p < 0.001). There was a positive interaction between distress during Mid-Feeding Delay and infant age predicting the amount consumed in the protocol (ß = 0.30, p = 0.022), suggesting that the association between distress during this part of the task and amount consumed strengthens as infants get older.

Conclusion

The ATDG-FIT may be an effective method to assess emerging eating behavior regulation constructs during early infancy.

Intermittent, extended access to preferred food leads to escalated food reinforcement and cyclic whole-body metabolism in rats: Sex differences and individual vulnerability

Compulsive binge eating is a hallmark of binge eating disorder and bulimia nervosa and is implicated in some obesity cases. Eating disorders are sexually dimorphic, with females more often affected than males. Animal models of binge-like eating based on intermittent access to palatable food exist; but, little is known regarding sex differences or individual vulnerability in these models with respect to the reinforcing efficacy of food, the development of compulsive- and binge-like eating, or associated changes in whole-body metabolism or body composition. Adolescent male (n = 24) and female (n = 32) Wistar rats were maintained on chow or a preferred, high-sucrose, chocolate-flavored diet in continuous or intermittent, extended access conditions. Body weight and composition, intake, fixed- and progressive-ratio operant self-administration, and whole body energy expenditure and respiratory exchange ratios were measured across an 11-week study period. Subgroup analyses were conducted to differentiate compulsive-like "high responder" intermittent access rats that escalated to extreme progressive-ratio self-administration performance vs. more resistant "low responders." Female rats had greater reinforcing efficacy of food than males in all diet conditions and were more often classified as "high responders". In both sexes, rats with intermittent access showed cycling of fuel substrate utilization and whole-body energy expenditure. Further, "high-responding" intermittent access female rats had especially elevated respiratory exchange ratios, indicating a fat-sparing phenotype. Future studies are needed to better understand the molecular and neurobiological basis of the sex and individual differences we have observed in rats and their translational impact for humans with compulsive, binge eating disorders.