Rebecca L Griggs

Parental beliefs about portion size, not children's own beliefs, predict child BMI

Increases in portion size are thought by many to promote obesity in children. However, this relationship remains unclear. Here, we explore the extent to which a childs BMI is predicted both by parental beliefs about their childs ideal and maximum portion size and/or by the childs own beliefs.

Better governance, better access: practising responsible data sharing in the METADAC governance infrastructure

BackgroundGenomic and biosocial research data about individuals is rapidly proliferating, bringing the potential for novel opportunities for data integration and use. The scale, pace and novelty of these applications raise a number of urgent sociotechnical, ethical and legal questions, including optimal methods of data storage, management and access. Although the open science movement advocates unfettered access to research data, many of the UK’s longitudinal cohort studies operate systems of managed data access, in which access is governed by legal and ethical agreements between stewards of research datasets and researchers wishing to make use of them. Amongst other things, these agreements aim to respect the reasonable expectations of the research participants who provided data and samples, as expressed in the consent process. Arguably, responsible data management and governance of data and sample use are foundational to the consent process in longitudinal studies and are an important source of trustworthiness in the eyes of those who contribute data to genomic and biosocial research.MethodsThis paper presents an ethnographic case study exploring the foundational principles of a governance infrastructure for Managing Ethico-social, Technical and Administrative issues in Data ACcess (METADAC), which are operationalised through a committee known as the METADAC Access Committee. METADAC governs access to phenotype, genotype and ‘omic’ data and samples from five UK longitudinal studies.FindingsUsing the example of METADAC, we argue that three key structural features are foundational for practising responsible data sharing: independence and transparency; interdisciplinarity; and participant-centric decision-making. We observe that the international research community is proactively working towards optimising the use of research data, integrating/linking these data with routine data generated by health and social care services and other administrative data services to improve the analysis, interpretation and utility of these data. The governance of these new complex data assemblages will require a range of expertise from across a number of domains and disciplines, including that of study participants. Human-mediated decision-making bodies will be central to ensuring achievable, reasoned and responsible decisions about the use of these data; the METADAC model described in this paper provides an example of how this could be realised.

Breaking the fast: Meal patterns and beliefs about healthy eating style are associated with adherence to intermittent fasting diets

Many believe that eating three meals each day is healthy and that skipping meals can be detrimental. What remains unclear is whether this belief undermines attempts to restrict energy intake by skipping meals. In an online survey, participants (N = 312) with experience of intermittent fasting (IF) reported their beliefs about healthy meal and snack frequency, as well as their non-fasting-dasy and fasting-day eating patterns. They also reported their level of concern with fasting-day meal patterns and their concern to generate fullness when selecting foods. Individuals currently following an IF diet (Current-IF dieters) and those who had previously attempted an IF diet but were non-adherent (Former-IF dieters) took part. Former-IF dieters were more likely to believe that it is healthy to eat three meals a day, punctuated by several snacks. On fasting-days, Former-IF dieters were also more likely to eat breakfast, a mid-morning snack, lunch, and a mid-afternoon snack whereas Current-IF dieters tended to save their eating for dinner and a late evening snack. Former-IF dieters were also more likely to be concerned about the negative consequences of missing a meal, to eat in anticipation of future hunger, and to prioritise fullness over taste when selecting foods. These findings reveal how beliefs about a healthy eating style can play an important role in shaping dietary patterns. Interventions aimed at modifying beliefs about healthy meal patterns may promote IF diet adherence.

Individual variability in preference for energy-dense foods fails to predict child BMI percentile

Many studies show that higher dietary energy density is associated with greater body weight. Here we explored two propositions: i) that child BMI percentile is associated with individual differences in childrens relative preference for energy-dense foods, ii) that child BMI percentile is associated with the same individual differences between their parents. Child-parent dyads were recruited from a local interactive science center in Bristol (UK). Using computerized tasks, participants ranked their preference and rated their liking for a range of snack foods that varied in energy density. Children (aged 3–14 years, N = 110) and parents completed the tasks for themselves. Parents also completed two further tasks in which they ranked the foods in the order that they would prioritize for their child, and again, in the order that they thought their child would choose. Children preferred (t(109) = 3.91, p < 0.001) and better liked the taste of (t(109) = 3.28, p = 0.001) higher energy-dense foods, and parents correctly estimated this outcome (t(109) = 7.18, p < 0.001). Conversely, lower energy-dense foods were preferred (t(109) = − 4.63, p < 0.001), better liked (t(109) = − 2.75, p = 0.007) and served (t(109) = − 15.06, p < 0.001) by parents. However, we found no evidence that child BMI percentile was associated with child or parent preference for, or liking of, energy-dense foods. Therefore, we suggest that the observed relationship between dietary energy density and body weight is not explained by individual differences in preference for energy density.

The effects of expectancy information on cephalic phase responses to food

It is well-established that exposure to the sight and smell of food enhances motivation to eat and initiates cephalic phase responses (CPRs) such as increased salivation, heart rate and blood flow to the liver. However, the effect of expectancy information in food-cue reactivity studies is not well-understood; that is, whether the participants expect to subsequently eat the cued food. Because CPRs prepare the body for consumption of food, these responses might be reduced when participants are explicitly told that they will not receive the cued food. The current study tested this proposition in a within-subjects design where female participants (i) expected to eat the cued food, (ii) did not expect to eat the cued food, and (iii) took part in a no-food-cue control condition. Measures of salivation and appetite were taken before and after exposure to the food cue. A novel continuous measure of liver temperature (a proxy for blood flow) was also taken using wireless monitoring devices (iButtons®); these devices were placed in the vicinity of the liver using ultrasonography. Results indicated no effects of expectancy information on rated hunger and salivation following food-cue exposure. However, subsequent food consumption was associated with significant increases in liver temperature. These findings provide novel insight into changes in liver temperature that occur during food-cue exposure and post-prandially.