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

Evaluation of an experiment to increase availability of healthier snack foods in vending machines situated within English sports facilities

Abstract Objective: to evaluate the impact of increased availability of healthier options on purchasing of different types of vending snack products sold in English leisure (sports) centres. Design: An evaluation of an intervention using pre-post methods and interrupted time series analysis. Products within the vending machines were altered over three phases to increase availability of healthier options, using agreed nutrition criteria - Government Buying Standards for Food and Catering Services (GBSF) for England - as a guide; as well as product availability. The primary outcome was the change in mean weekly purchased energy between the first and third phase. Secondary outcomes included changes by phase and by week in weekly number of purchases, fats, sugars and salt for all products combined and by individual product categories. Setting: 15 sports centres in the city of Leeds, West Yorkshire, UK. Participants: Snack products sold in 18 vending machines. Results: Energy purchased reduced from baseline to phase 2, for all product categories combined, by 47.25MJ (95% CI -61.22 to -33.27MJ) per machine and by 279KJ, (95% CI -325 to -266KJ) per product unit. There were reductions in most nutrients purchased in all individual product categories except chocolate confectionery. Nutrients per product unit decreased for all product categories except saturated fat in chocolate confectionery. Minimal underlying trends in the baseline phase were identified, indicating changes in outcomes were likely to be due to the intervention. Conclusions: Introducing standards to increase the availability of healthier snack products in vending machines is feasible without substantially affecting sales

Does food portion size differ by level of household income? A cross-sectional study using the UK National Diet and Nutrition Survey 2008–11

Background: in developed countries, disadvantaged groups have higher prevalence of obesity and its associated chronic diseases than do high income groups. This study aimed to investigate the association between the level of household income and food portion size for the top 20 most frequently consumed foods by adolescents and adults.Methods: data for this study came from the UK National Diet and Nutritional Survey (2008–11). Using a 4 day estimated food record, we calculated food portion size for 567 adolescents (11–18 years) and 992 adults (19–65 years). For each participant, average portion size for each food was calculated by dividing the total weight of the food by the frequency of consumption; then the average food portion size was calculated for each food for the whole sample. This method avoided portion sizes being skewed because of individuals who frequently consumed small or large portions. Levels of income were classified by household income per year: low (?£24?999), middle (£25?000–49?999), and high (?£50?000). Associations with food portion size were tested with multivariable regression models adjusting for sex and age (significance at p?0·01).Findings: 205, 226, and 136 adolescents and 395, 379, and 218 adults were classified as having low, middle, and high household incomes, respectively. Adolescents from low income households consumed smaller portions of “tap water” than did those in high income households (by 52 mL, 99% CI 7–97; p<0·0001). Adolescents from middle income households consumed larger food portion sizes of “carbonated soft drinks” than did those from high income households (40 mL, 2–81; p=0·01). Adults in low income households consumed larger food portion sizes of “cheese”, “mashed potato”, and “savoury sauces, pickles” (by 9 g [2–15], 25 g [2–15], and 12 g [7–43], respectively; p<0·0001), and drank smaller portions of “tap water” (34 mL [3–71], p=0·01) than did those from high income households. No significant differences were seen in food portion sizes between adults in middle and high income households.Interpretation: portion sizes of only a few foods differed by household income; nonetheless, these foods might contribute to inequalities in healthy dietary intake in both adults and adolescents. More attention should be given to both food and drink portion sizes when planning public health nutrition interventions and policy programmes aimed at closing the socioeconomic gap in obesity and chronic disease morbidity and mortalit

Dietary fiber intake and risk of first stroke: A systematic review and meta-analysis

Background and Purpose—Fiber intake is associated with reduced stroke risk in prospective studies, but no meta-analysis has been published to date. Methods—Multiple electronic databases were searched for healthy participant studies reporting fiber intake and incidence of first hemorrhagic or ischemic stroke, published between January 1990 and May 2012. Results—Eight cohort studies from the United States, northern Europe, Australia, and Japan met inclusion criteria. Total dietary fiber intake was inversely associated with risk of hemorrhagic plus ischemic stroke, with some evidence of heterogeneity between studies (I2; relative risk per 7 g/day, 0.93; 95% confidence interval, 0.88–0.98; I2=59%). Soluble fiber intake, per 4 g/day, was not associated with stroke risk reduction with evidence of low heterogeneity between studies, relative risk 0.94 (95% confidence interval, 0.88–1.01; I2=21%). There were few studies reporting stroke risk in relation to insoluble fiber or fiber from cereals, fruit, or vegetables. Conclusions—Greater dietary fiber intake is significantly associated with lower risk of first stroke. Overall, findings support dietary recommendations to increase intake of total dietary fiber. However, a paucity of data on fiber from different foods precludes conclusions regarding the association between fiber type and stroke. There is a need for future studies to focus on fiber type and to examine risk for ischemic and hemorrhagic strokes separately