The effectiveness of a social media intervention for reducing portion sizes in young adults and adolescents

open access journalAbstract Objective: Adolescents and young adults select larger portions of energy-dense food than recommended. The majority of young people have a social media profile, and peer influence on social media may moderate the size of portions selected. Methods: Two pilot-interventions examined whether exposure to images of peers’ portions of high-energy-dense (HED) snacks and sugar-sweetened-beverages (SSBs) on social media (Instagram) would influence reported desired portions selected on a survey. Confederate peers posted ‘their’ portions of HED snacks and SSBs on Instagram. At baseline and intervention end participants completed surveys that assessed desired portion sizes. Results: In intervention 1, Undergraduate students (N=20, Mean age=19.0y, SD=0.65y) participated in a two-week intervention in a within-subjects design. Participants reported smaller desired portions of HED snacks and SSBs following the intervention, and smaller desired portions of HED snacks for their peers. In intervention 2, adolescents (N=44, Mean age=14.4y, SD=1.06y) participated in a four-week intervention (n=23) or control condition (n=21) in a between-subjects design. Intervention 2 did not influence adolescents to reduce their desired reported portion sizes of HED snacks or SSBs relative to control. Conclusions: These preliminary studies demonstrated that social media is a feasible way to communicate with young people. However, while the intervention influenced young adults’ reported desired portions and social norms regarding their peers’ portions, no significant impact on desired reported portion sizes was found for HED snacks and SSBs in adolescents. Desired portion sizes of some foods and beverages may be resistant to change via a social media intervention in this age group

Lesions of the basolateral amygdala disrupt selective aspects of reinforcer representation in rats

The amygdala is known to play a role in learning about motivationally significant events. We investigated this role further by examining the effects of excitotoxic lesions of the basolateral amygdala on the ability of rats to use instrumental outcomes to direct responding (the differential outcomes effect) and on the ability of Pavlovian cues to modulate instrumental performance based on shared outcomes (reinforcer–selective Pavlovian-to-instrumental transfer). We found that basolateral amygdala (BLA) lesions did not affect the ability of rats to learn a basic instrumental conditional discrimination, but did disrupt the ability of differential outcomes to facilitate acquisition. In Pavlovian-to-instrumental transfer, BLA lesions did not disrupt the basic enhancement of instrumental performance but did abolish the reinforcer specificity of that enhancement. These results suggest that the BLA is involved in the representation of the sensory aspects of motivationally significant events

Systematic review and meta-analysis of strategies to increase vegetable consumption in preschool children aged 2-5 years

Background Most children do not meet daily recommendations for fruit and vegetable intake, and consumption of vegetables remains especially low. Eating habits track from childhood to adulthood hence establishing liking and intake of vegetables is important. Objective To identify the most successful strategies to enhance vegetable intake in preschool children aged 2–5 years. Design The research was a systematic review and a meta-analysis of published studies. A comprehensive search strategy was performed using key databases such as Medline, Embase, PsychINFO, EBSCO and CENTRAL. Articles published between 2005–January 2016, specifically with measured vegetable consumption were included. Results 30 articles and 44 intervention arms were identified for inclusion (n = 4017). Nine dominant intervention strategies emerged to promote vegetable intake in preschool children. These included; choice, pairing (stealth), education, food service, modelling, reward, taste exposure, variety and visual presentation. The meta-analysis revealed that interventions implementing repeated taste exposure had better pooled effects than those which did not. Intake increased with number of taste exposures and intake was greater when vegetables offered were in their plain form rather than paired with a flavor, dip or added energy (e.g. oil). Moreover, intake of vegetables which were unfamiliar/disliked increased more than those which were familiar/liked. Conclusions Repeated taste exposure is a simple technique that could be implemented in childcare settings and at home by parents. Health policy could specifically target the use of novel and disliked vegetables in childcare settings with emphasis on a minimum 8–10 exposures. The systematic review protocol was registered on the PROSPERO (number: CRD42016033984)

Understanding the science of portion control and the art of downsizing

Offering large portions of high-energy-dense (HED) foods increases overall intake in children and adults. This is known as the portion size effect (PSE). It is robust, reliable and enduring. Over time, the PSE may facilitate overeating and ultimately positive energy balance. Therefore, it is important to understand what drives the PSE and what might be done to counter the effects of an environment promoting large portions, especially in children. Explanations for the PSE are many and diverse, ranging from consumer error in estimating portion size to simple heuristics such as cleaning the plate or eating in accordance with consumption norms. However, individual characteristics and hedonic processes influence the PSE, suggesting a more complex explanation than error or heuristics. Here PSE studies are reviewed to identify interventions that can be used to downsize portions of HED foods, with a focus on children who are still learning about social norms for portion size. Although the scientific evidence for the PSE is robust, there is still a need for creative downsizing solutions to facilitate portion control as children and adolescents establish their eating habits

Dielectric relaxations in PEEK by combined dynamic dielectric spectroscopy and thermally stimulated current

The molecular dynamics of a quenched poly (ether ether ketone) (PEEK) was studied over a broad frequency range from 10-3 to 106 Hz by combining dynamic dielectric spectroscopy (DDS) and thermo-stimulated current (TSC) analysis. The dielectric relaxation losses e00 KK has been determined from the real part e0 T(x) thanks to Kramers–Kronig transform. In this way, conduction and relaxation processes can be analyzed independently. Two secondary dipolar relaxations, the c and the b modes, corresponding to non-cooperative localized molecular mobility have been pointed out. The main a relaxation appeared close to the glass transition temperature as determined by DSC; it has been attributed to the delocalized cooperative mobility of the free amorphous phase. The relaxation times of dielectric relaxations determined with TSC at low frequency converge with relaxation times extracted from DDS at high frequency. This correlation emphasized continuity of mobility kinetics between vitreous and liquid state. The dielectric spectroscopy exhibits the ac relaxation, near 443 K, which has been associated with the rigid amorphous phase confined by crystallites. This present experiment demonstrates coherence of the dynamics of the PEEK heterogeneous amorphous phase between glassy and liquid state and significantly improve the knowledge of molecular/dynamic structure relationships

Learning to Eat Vegetables in Early Life: The Role of Timing, Age and Individual Eating Traits

Vegetable intake is generally low among children, who appear to be especially fussy during the pre-school years. Repeated exposure is known to enhance intake of a novel vegetable in early life but individual differences in response to familiarisation have emerged from recent studies. In order to understand the factors which predict different responses to repeated exposure, data from the same experiment conducted in three groups of children from three countries (n = 332) aged 4–38 m (18.9±9.9 m) were combined and modelled. During the intervention period each child was given between 5 and 10 exposures to a novel vegetable (artichoke puree) in one of three versions (basic, sweet or added energy). Intake of basic artichoke puree was measured both before and after the exposure period. Overall, younger children consumed more artichoke than older children. Four distinct patterns of eating behaviour during the exposure period were defined. Most children were “learners” (40%) who increased intake over time. 21% consumed more than 75% of what was offered each time and were labelled “plate-clearers”. 16% were considered “non-eaters” eating less than 10 g by the 5th exposure and the remainder were classified as “others” (23%) since their pattern was highly variable. Age was a significant predictor of eating pattern, with older pre-school children more likely to be non-eaters. Plate-clearers had higher enjoyment of food and lower satiety responsiveness than non-eaters who scored highest on food fussiness. Children in the added energy condition showed the smallest change in intake over time, compared to those in the basic or sweetened artichoke condition. Clearly whilst repeated exposure familiarises children with a novel food, alternative strategies that focus on encouraging initial tastes of the target food might be needed for the fussier and older pre-school children

Determinants of Portion Size in Children and Adolescents: Insights from the UK National Diet and Nutrition Survey Rolling Programme (2008–2016)

Large portion sizes have been identified as contributing to overweight and obesity, particularly in children and adolescents. This study examined predictors of portion sizes of high energy snack foods eaten by children aged 1.5–18 years. Specifically, we examined whether portion sizes were adjusted for age, and what external features of the environment might be linked to large portion sizes. Portion sizes were derived from four-day food diaries that form the UK National Diet and Nutrition Survey. Diaries from 5942 children were examined and multilevel models were used to discover whether age, gender, location, time of day, household income, and watching TV while eating predicted portion sizes of savoury snacks, chocolate, confectionery and biscuits. Portion sizes of all the target foods were predicted by age. Boys had larger portions, and portion sizes were larger when target foods were consumed later in the day. Portion sizes were larger outside the home, for example in leisure venues, but the target foods were eaten more frequently in the home. As dietary patterns change to include more snack intake outside the home, these locations could be an important space to target for interventions for portion control

Lesions of the basolateral amygdala disrupt selective aspects of reinforcer representation in rats

The amygdala is known to play a role in learning about motivationally significant events. We investigated this role further by examining the effects of excitotoxic lesions of the basolateral amygdala on the ability of rats to use instrumental outcomes to direct responding (the differential outcomes effect) and on the ability of Pavlovian cues to modulate instrumental performance based on shared outcomes (reinforcer–selective Pavlovian-toinstrumental transfer). We found that basolateral amygdala (BLA) lesions did not affect the ability of rats to learn a basic instrumental conditional discrimination, but did disrupt the ability of differential outcomes to facilitate acquisition. In Pavlovianto-instrumental transfer, BLA lesions did not disrupt the basic enhancement of instrumental performance but did abolish the reinforcer specificity of that enhancement. These results suggest that the BLA is involved in the representation of th

“I still put them on her plate”: A qualitative study exploring strategies implemented by parents to promote vegetable intake

This study explored strategies implemented by parents to encourage their children to eat vegetables, especially when children exhibit fussy eating. The study involved a mixed methods approach using semi-structured interviews with twenty parents of preschool children (aged 2-5 years) with a high and low level of food fussiness (established by questionnaire). All interviews were audio recorded, then verbatim transcribed and analyzed using thematic analysis. Thematic analysis revealed seven main themes with sixteen subthemes encompassing various vegetable promoting strategies. These included (1) Instructed knowledge, (2) Experiential learning, (3) Food manipulation, (4) Reinforcement, (5) Encouragement of autonomy (6) Commitment to a food ideal and (7) Inherent values. Parents used a range of methods to encourage their children to eat vegetables but there were no major differences by level of food fussiness. Parents talked about variable success in applying strategies even with the same child. Home based strategies were more diverse and personalized to the child than those tested in most research studies. Therefore, interventions to promote vegetable intake in preschool children will benefit from co-production with parents adopting a tailored approach to match the needs of the specific child