Tracy A. McCaffrey

Snacking patterns among adolescents: a comparison of type, frequency and portion size between Britain in 1997 and Northern Ireland in 2005.

Despite the potential link between snack food intake and obesity and the reportedly high prevalence of snacking among adolescents, adolescent snack food patterns (types of foods consumed, frequency and portion size) have not been extensively examined. This study examines these issues using data on the snacking patterns of adolescents aged 13-16 years who took part in the 1997 National Diet and Nutrition Survey (NDNS) and that from a Northern Irish (NI) cohort of adolescents collected 8 years later, in 2005. Overall energy intake was significantly higher in the NI adolescents in 2005 compared with the NDNS adolescents in 1997 (P < 0.01). Consequently, energy intake from snacks was significantly higher in the NI cohort (P < 0.01) and a trend for a higher % energy intake from snacks compared with the NDNS group was observed (median 32.5% v. 29.8%, respectively). Sugar-sweetened carbonated and soft drinks remained the most popular choice of snack over this 8-year period; however, both the portion size consumed and frequency of consumption were significantly higher among the adolescents in 2005 compared with those in 1997 (P = 0.022 and P = 0.014, respectively). Despite the lower popularity, and correspondingly lower frequency of milks and beverages, the portion size of both food groups was significantly higher among the adolescents in 2005 compared with those in 1997 (P < 0.001 and P = 0.007, respectively). These findings may provide scope for policy interventions to place particular emphasis on reducing typical portion sizes consumed of popular snack choices, in particular high-energy carbonated and soft drinks, among UK adolescents.

Childhood obesity prevention studies: lessons learned and to be learned

OBJECTIVE To provide an overview of methodological issues in the design, delivery and evaluation of childhood obesity prevention programmes. DESIGN Review of existing literature. SETTING International. RESULTS Interventions have varied considerably with regard to their design, subject selection criteria, sample size, attrition rates, intervention components and duration of both the intervention and the follow-up phases. However, overall, there is only a limited body of consistent, high-quality evidence on which valid and generalisable conclusions can be drawn about best practices for the prevention of childhood obesity. CONCLUSIONS Although the rationale for targeting children and adolescents through primary prevention is now compelling, effective obesity prevention remains elusive. There is increasing consensus that prevention of childhood obesity necessitates multifaceted health promotion interventions based on population health principles. By definition, such interventions should have a range of outcome indicators of effectiveness, generalisability and sustainability, not just the traditional ones focused on individual lifestyle behaviour change. Given the complexity and intricacy of population-based intervention programmes, multiple methods of data collection which combine both qualitative and quantitative approaches will need to be fully exploited in order to move towards evidence-based practice in the future.

Investigation of the medium-term effects of Olibra™ fat emulsion on food intake in non-obese subjects

Objective:To investigate the effect of Olibra™ fat emulsion on medium-term food intake and appetite in non-obese subjects.Design:Double-blind, placebo-controlled, within-subject crossover.Setting:University of Ulster, Coleraine.Subjects:A total of 28 subjects (14 male, 14 female).Interventions:Subjects were randomly assigned to receive either a 200 g portion of test (5 g of Olibra™ fat) or control (5 g milk fat) yoghurt for breakfast for 2 × 3 week ‘study’ phases, separated by a 3-week ‘wash-out’ phase. On days 1, 8 and 22 of the study phases, food intake 4 h post-consumption of the yoghurt was assessed by pre- and post-covert weighing at an ad libitum buffet-style test lunch. Throughout each of these study days, appetite was assessed using visual analogue scales (VAS) at regular intervals. For the remainder of the study days, and the following 24 h (‘post-study days’), subjects reported their food intake using weighed dietary records.Results:Consumption of the Olibra™ emulsion had no significant effect on mean energy, macronutrient or amounts of food consumed at the lunch 4 h post-consumption. Self-reported food intakes indicated that there was no significant effect of the emulsion on energy intakes for the remainder of each study day and post-study days. There was considerable individual variation in food intakes following consumption of the Olibra™ emulsion, with 46, 59 and 57% of subjects reducing their energy intakes at lunch on days 1, 8 and 22. There was no consistent effect of the emulsion on appetite ratings.Conclusions:In contrast to earlier studies, there was no evidence of a short- or medium-term effect of the Olibra™ emulsion on food intake or appetite. This could be owing to numerous confounding factors influencing eating behaviour and/or the different study design used in the present study.

Associations of dietary glycaemic index and glycaemic load with food and nutrient intake and general and central obesity in British adults.

Inconsistent associations between dietary glycaemic index (GI) and glycaemic load (GL) and body fatness may be partly due to differences in the underlying dietary patterns or energy under-reporting. In the present study, we examined the cross-sectional associations of dietary GI and GL with food and nutrient intake and general and central obesity, accounting for energy under-reporting. The subjects were 1487 British adults aged 19-64 years. Dietary intake was assessed using a 7 d weighed dietary record. Breads and potatoes were the positive predictive foods for dietary GI, while fruit, other cereals and dairy products were the negative predictors. These foods were similarly identified in the analysis of only acceptable reporters (AR; ratio of reported energy intake:estimated energy requirement within 0·665-1·335) and under-reporters (UR; ratio < 0·665). Dietary GL was closely correlated with carbohydrate intake. Multiple linear regression analyses showed that dietary GI was independently associated with a higher risk of general obesity (BMI ≥ 30 kg/m²) and central obesity (waist circumference ≥ 102 cm in men and ≥ 88 cm in women). Dietary GL was also associated with general (only women) and central obesity. Similarly, in the analysis of AR, the GI showed positive associations with general and central obesity, and, only in women, the GL showed positive associations with general and central obesity. Conversely, in the analysis of UR, the associations were generally weaker and many of them failed to reach statistical significance. In conclusion, we found independent positive associations of dietary GI and GL with general and central obesity in British adults.

Perceived ‘healthiness’ of foods can influence consumers’ estimations of energy density and appropriate portion size

OBJECTIVE:To compare portion size (PS) estimates, perceived energy density (ED) and anticipated consumption guilt (ACG) for healthier vs standard foods.METHODS:Three pairs of isoenergy dense (kJ per 100 g) foods—healthier vs standard cereals, drinks and coleslaws—were selected. For each food, subjects served an appropriate PS for themselves and estimated its ED. Subjects also rated their ACG about eating the food on a scale of 1 (not at all guilty) to 5 (very guilty).RESULTS:Subjects (n=186) estimated larger portions of the healthier coleslaw than that of the standard version, and perceived all healthier foods to be lower in ED than their standard alternatives, despite being isoenergy dense. Higher ACG was associated with the standard foods. Portion estimates were generally larger than recommendations and the ED of the foods was underestimated.CONCLUSIONS:The larger portions selected for the ‘reduced fat’ food in association with lower perceived ED and ACG suggests that such nutrition claims could be promoting inappropriate PS selection and consumption behaviour. Consumer education on appropriate portions is warranted to correct such misconceptions.

Dietary glycaemic index and glycaemic load in relation to food and nutrient intake and indices of body fatness in British children and adolescents

The diversity of the associations of dietary glycaemic index (GI) and glycaemic load (GL) with dietary intake and body fatness observed in epidemiological studies may be partly due to the differences in underlying dietary intake patterns. We examined the cross-sectional associations of dietary GI and GL with food and nutrient intakes and indices of body fatness in 818 children aged 4-10 years and 818 adolescents aged 11-18 years in Britain, based on the data from the National Diet and Nutrition Survey. Dietary intake was assessed using a 7 d weighed dietary record. Overweight was defined as BMI ≥ 85th percentile of the age- and sex-specific British growth reference data. Central obesity was defined as waist:height ratio (WHtR) ≥ 0·5 (adolescents only). Breads, breakfast cereals and potatoes were the positive predictive food groups for dietary GI, while dairy products, fruit juice, other cereals and fruit were the negative predictors. Dietary GL was closely correlated with carbohydrate intake. Dietary GI showed no associations with overweight or central obesity. Conversely, dietary GL showed an independent association with a higher risk of overweight in children and a higher risk of central obesity (but not overweight) in adolescents. However, dietary GI and GL were not associated with BMI z-score in children and adolescents or WHtR in adolescents. In conclusion, the present study showed that dietary GL was independently associated with overweight in children and with central obesity in adolescents. Nevertheless, given no associations when body fatness measures were treated as continuous variables, the results must be interpreted cautiously.

Estimation of the dietary intake of 13 priority additives in France, Italy, the UK and Ireland as part of the FACET project

The aim of this study was to assess the dietary exposure of 13 priority additives in four European countries (France, Italy, the UK and Ireland) using the Flavourings, Additives and Contact Materials Exposure Task (FACET) software. The studied additives were benzoates (E210–213), nitrites (E249–250) and sulphites (E220–228), butylated hydroxytoluene (E321), polysorbates (E432–436), sucroses esters and sucroglycerides (E473–474), polyglycerol esters of fatty acids (E475), stearoyl-lactylates (E481–482), sorbitan esters (E493–494 and E491–495), phosphates (E338–343/E450–452), aspartame (E951) and acesulfame (E950). A conservative approach (based on individual consumption data combined with maximum permitted levels (Tier 2)) was compared with more refined estimates (using a fitted distribution of concentrations based on data provided by the food industry (Tier 3)). These calculations demonstrated that the estimated intake is below the acceptable daily intake (ADI) for nine of the studied additives. However, there was a potential theoretical exceedance of the ADI observed for four additives at Tier 3 for high consumers (97.5th percentile) among children: E220–228 in the UK and Ireland, E432–436 and E481–482 in Ireland, Italy and the UK, and E493–494 in all countries. The mean intake of E493–494 could potentially exceed the ADI for one age group of children (aged 1–4 years) in the UK. For adults, high consumers only in all countries had a potential intake higher than the ADI for E493–494 at Tier 3 (an additive mainly found in bakery wares). All other additives examined had an intake below the ADI. Further refined exposure assessments may be warranted to provide a more in-depth investigation for those additives that exceeded the ADIs in this paper. This refinement may be undertaken by the introduction of additive occurrence data, which take into account the actual presence of these additives in the different food groups. Graphical Abstract

Influencing and modifying children's energy intake: the role of portion size and energy density

Childhood obesity is of concern worldwide. The portion size (PS) and energy density (ED) of food are two major determinants of childrens energy intake (EI). Trends towards increasing PS are most apparent and best documented in the USA, where PS of numerous food products have increased in the marketplace over the past three decades, particularly high-energy dense foods. Analyses of population-level dietary surveys have confirmed this trend in children for both in- and out-of-home eating, and a plethora of observational evidence positively associates PS, ED and adiposity in children. A limited number of intervention studies provide clear evidence that children, even as young as 2 years, respond acutely to increasing PS, with some studies also demonstrating the additive effects of increased ED in promoting excessive EI. However, most of the evidence is based on children aged 3-6 years and there is a paucity of data in older children and adolescents. It is unclear whether decreasing PS can have the opposite effect on childrens EI but recent acute studies have demonstrated that the incorporation of lower energy dense foods, such as fruit and vegetables, into childrens meals down-regulates EI. Although a direct causal link between PS and obesity remains to be established, the regular consumption of larger PS of energy dense foods do favour obesity-promoting eating behaviours in children. Further research is required to establish the most feasible and effective interventions and policies to counteract the deleterious impact of PS and ED on childrens EI.

Parent and child perspectives on family out-of-home eating: A qualitative analysis

OBJECTIVE To (i) explore the factors influencing family out-of-home (OH) eating events and (ii) identify possible opportunities for food businesses to support families in making healthier OH choices. DESIGN Focus group discussions were conducted with parents (six to eight participants per group) and friendship pair discussions (informal interviews with two children who are friends) were conducted with children (5-12 years) throughout the island of Ireland. Both discussions were audio-recorded and analysed using a thematic content analysis. SETTING Eight focus groups and sixteen friendship pairs were conducted in Northern Ireland and sixteen focus groups and thirty-two friendship pairs were conducted in the Republic of Ireland. SUBJECTS Purposive sampling was used to recruit a sample of non-related parents and children that represented equal numbers of gender, age, socio-economic status and demographic backgrounds. RESULTS The main, overarching theme was that families perceived OH eating to be a treat, while health was not currently a key priority for many parents and children. Children were reported to have most responsibility for their own food choice decisions in this environment, with taste and food neophobia having the greatest influences. Parents believed that if food businesses could meet parent and child priorities in addition to health influences, e.g. change cooking methods, and increase flexibility, then families would be more likely to patronise these establishments. CONCLUSIONS The entire family OH eating experience needs to be considered when developing public health interventions and this research has highlighted key opportunities that caterers could employ to support healthier family OH food choices.

Influences on Dietary Choices during Day versus Night Shift in Shift Workers: A Mixed Methods Study

Shift work is associated with diet-related chronic conditions such as obesity and cardiovascular disease. This study aimed to explore factors influencing food choice and dietary intake in shift workers. A fixed mixed method study design was undertaken on a convenience sample of firefighters who continually work a rotating roster. Six focus groups (n = 41) were conducted to establish factors affecting dietary intake whilst at work. Dietary intake was assessed using repeated 24 h dietary recalls (n = 19). Interviews were audio recorded, transcribed verbatim, and interpreted using thematic analysis. Dietary data were entered into FoodWorks and analysed using Wilcoxon signed-rank test; p < 0.05 was considered significant. Thematic analysis highlighted four key themes influencing dietary intake: shift schedule; attitudes and decisions of co-workers; time and accessibility; and knowledge of the relationship between food and health. Participants reported consuming more discretionary foods and limited availability of healthy food choices on night shift. Energy intakes (kJ/day) did not differ between days that included a day or night shift but greater energy density (EDenergy, kJ/g/day) of the diet was observed on night shift compared with day shift. This study has identified a number of dietary-specific shift-related factors that may contribute to an increase in unhealthy behaviours in a shift-working population. Given the increased risk of developing chronic diseases, organisational change to support workers in this environment is warranted.