How can different psychological and behavioural constructs be used to personalise weight management? Development of the diet styles.

The aim of this study was first, to explore whether distinct combinations of key psychological and eating-related characteristics, could be identified and, second, whether these styles were related to measures of dieting success such as weight status and the number of previous weight loss attempts. Participants were any person 18 years or older with access to the internet and were recruited through Facebook to complete a 30-min, online survey. The survey included 23 different measures of factors related to personality, eating behaviours and current weight management. 1047 (68.3% of starters) completed the full survey. These people were 82.4% female with a mean age of 42.54 years (SD = 14.07). Factor analysis using Maximum Likelihood Extraction method with Promax rotation resulted in the extraction of 5 novel factors: Temptation (including experiencing cravings and difficulty controlling eating); Foodie (higher engagement and involvement with food); Overthinking (neuroticism, behavioural inhibition and perfectionistic tendencies); Social (extroversion and agreeableness); Impulsivity (impulsivity, lower conscientiousness, higher fun-seeking). Each of the factors associated bivariately, and in the expected direction, with behaviours such as vegetable consumption, frequency of diet attempts, and self-rated health. Each possible diet style is described further and interpreted in the context of existing literature with a focus on how understanding these could help personalise future interventions. Future work will validate this structure in different samples.

How much does what you eat matter? The potential role of meal size, fat content, and gender on ratings of desirability.

This study examined how the amount and type of food that a person eats affects perceptions of their personal desirability, femininity/masculinity, and body size while accounting for any assumed similarity biases. Female students (18 to 59 years old) were recruited through the School of Psychology at the University of Adelaide. Participants (n = 191) rated the characteristics of a fictional person based on information in a personal profile. Profiles were identical aside from experimental manipulations of gender (male/female), meal size (small/large) and meal type (regular fat/high fat) with meal manipulations calculated using nutrient recommendations. Ratings of desirability and body size were affected primarily by meal type with targets described as eating a regular fat meal seen as more desirable (M = 5.40, SD = 0.56) and thinner (M = 3.93, SD = 1.05) than those having a high fat meal (M = 5.09, SD = 0.66; M = 4.29, SD = 1.04) (p = .001). Meal size manipulations affected only ratings of body size with larger meals (M = 4.25, SD = 0.88) resulting in higher ratings relative to smaller meals (M = 3.96, SD = 1.20) (p = .036). Despite a suggestion of interactions between target gender and both meal characteristics for ratings of femininity/masculinity in our results, post-hoc analyses largely failed to reveal any pairwise differences. Perceived similarity to the target did relate to levels of desirability (p = .006), and self-esteem positively associated with ratings of target body size (p = .010). Even though men's perceptions of eating behaviours were not reported in this paper, these findings have implications for a better understanding of social pressures faced not only by women, but also for men, as potentially both genders may be affected by eating norms regarding the healthiness of a meal.

Ingesting breakfast meals of different glycaemic load does not alter cognition and satiety in children.

BACKGROUND/OBJECTIVES: The effect of Glycaemic Index (GI) and Load (GL) of breakfasts on satiety and aspects of cognitive function in children is inconclusive. We aimed to assess if isocaloric breakfasts differing in GL (by replacing high-GI carbohydrate foods with dairy protein foods) acutely alter cognitive function and satiety in 10- to 12-year-old children. SUBJECTS/METHODS: A total of 39 children, aged 11.6±0.7 years with body mass index 18.9±3.0 kg/m² (Mean±s.e.) participated in a randomised crossover trial of three isocaloric breakfasts (1.3 MJ): high GL (HGL: 7 g protein, 9 g fat, 50 g carbohydrate, GL 33); medium GL (MGL: 14 g protein, 9 g fat, 45 g carbohydrate, GL 24) and low GL (LGL: 18 g protein, 10 g fat, 38 g carbohydrate, GL 18). Blood glucose was recorded using a continuous glucose monitor. Subjective hunger and cognitive performance were measured before and hourly after consuming the test breakfast via a computer-delivered battery. Ad libitum intake at a buffet lunch meal was measured at 3 h at the end of testing. RESULTS: Incremental area under the glucose curve (iAUC) was significantly different with HGL>MGL>LGL (P<0.001). Glucose concentrations fell below baseline after 83±6 min for HGL, 63±5 min (MGL) and 67±5 min (LGL)(P=0.009). Breakfast GL did not significantly alter changes in cognitive function or self-reported satiety throughout testing. Energy intake at lunch was not significantly different between treatments (HGL 2943±168 kJ; MGL 2949±166 kJ; LGL 2993±191 kJ). CONCLUSIONS: Reducing breakfast GL by replacing carbohydrate with protein does not alter satiety or cognition over 3 h in 10- to 12-year-old children.