Portion control tableware differentially impacts eating behaviour in women with and without overweight.

Portion control tableware has been described as a potentially effective approach for weight management, however the mechanisms by which these tools work remain unknown. We explored the processes by which a portion control (calibrated) plate with visual stimuli for starch, protein and vegetable amounts modulates food intake, satiety and meal eating behaviour. Sixty-five women (34 with overweight/obesity) participated in a counterbalanced cross-over trial in the laboratory, where they self-served and ate a hot meal including rice, meatballs and vegetables, once with a calibrated plate and once with a conventional (control) plate. A sub-sample of 31 women provided blood samples to measure the cephalic phase response to the meal. Effects of plate type were tested through linear mixed-effect models. Meal portion sizes (mean ± SD) were smaller for the calibrated compared with the control plate (served: 296 ± 69 vs 317 ± 78 g; consumed: 287 ± 71 vs 309 ± 79 g respectively), especially consumed rice (69 ± 24 vs 88 ± 30 g) (p < 0.05 for all comparisons). The calibrated plate significantly reduced bite size (3.4 ± 1.0 vs 3.7 ± 1.0 g; p < 0.01) in all women and eating rate (32.9 ± 9.5 vs 33.7 ± 9.2 g/min; p < 0.05), in lean women. Despite this, some women compensated for the reduced intake over the 8 h following the meal. Pancreatic polypeptide and ghrelin levels increased post-prandially with the calibrated plate but changes were not robust. Plate type had no influence on insulin, glucose levels, or memory for portion size. Meal size was reduced by a portion control plate with visual stimuli for appropriate amounts of starch, protein and vegetables, potentially because of the reduced self-served portion size and the resulting reduced bite size. Sustained effects may require the continued use of the plate for long-term impact.

Consumption of low-calorie sweetened drinks is associated with 'sweet satiation', but not with 'sweet-taste confusion': A virtual study.

Originating from studies on rats, the 'taste confusion' hypothesis predicts that exposure to low-calorie sweeteners (LCS) will impair compensatory responses to sugar intake, resulting in increased overall calorie intake. We conducted a virtual study in which young adult human participants (n = 332), who differed in their history of exposure to sweet drinks (e.g., drank 'diet' (LCS) soft drinks or 'regular' (sugar-sweetened) soft drinks), imagined consuming a cheese sandwich and two-thirds of a 500 ml drink (still water, sparkling water, diet Coca Cola, regular Coca Cola, or semi-skimmed milk), or no drink, as a hypothetical lunch-time meal. They then used a screen-based tool to select the amount of a sweet snack (chocolate M&M's) or savoury snack (salted peanuts) that they would eat immediately with the remaining third of their drink (i.e., a total of 12 drink and snack combinations per participant). The results were inconsistent with the predictions of the taste confusion hypothesis; specifically, the extent to which consumption of sugar cola compared with water (still or sparkling) reduced snack intake did not differ between habitual diet (LCS) and habitual sugar soft-drink consumers. Other results showed a 'sweet satiation' effect (i.e., lower sweet versus savoury snack intake when the drink accompanying the meal was sweet compared with when it was water), and negligible compensation in snack food intake for the difference in the energy content of diet versus sugar cola.

Virtual reality exergaming improves affect during physical activity and reduces subsequent food consumption in inactive adults.

An individual's affective (i.e. emotional) response to exercise may play an important role in post-exercise eating behaviour for some individuals. Taking advantage of advances in fully immersive virtual reality (VR) technology, this study aimed to: a) examine whether VR exergaming can improve the psychological response to exercise in inactive adults, and b) assess the extent to which this improvement reduces post-exercise appetite and eating behaviour. In a cross-over study, 34 adults not meeting the World Health Organisation's physical activity recommendations completed two exercise sessions on a stationary bike; one while engaging in a VR exergame and one without VR. Monitoring enabled heart rate, energy expenditure, and duration across conditions to be closely matched. The Physical Activity Enjoyment Scale, Feeling Scale, Felt Arousal Scale and Borg's Ratings of Perceived Exertion were measured to capture the affective responses to exercise. Appetite and eating behaviour were evaluated using visual-analogue scales, a computerised food preference task, and intake at a post-exercise buffet meal. Cycling in VR elicited greater exercise enjoyment (p < 0.001, η2p = 0.62), pleasure (p < 0.001, η2p = 0.47), and activation (p < 0.001, η2p = 0.55). VR exergaming did not alter perceived physical exertion (p = 0.64), perceived appetite (p = 0.68), and preference for energy dense (p = 0.78) or sweet/savoury foods (p = 0.90) compared to standard exercise. However, it did result in a mean 12% reduction in post-exercise food intake (mean difference: 105.9 kcal; p < 0.01; η2p = 0.20) and a decrease in relative food intake (p < 0.01; η2p = 0.20), although inter-individual differences in response to VR exergaming were observed. The integration of VR in a cycling workout improves the affective experience of physical activity for inactive adults and reduces subsequent food intake. Virtual reality technology shows potential as an adjunct tool to support adults in weight management programmes become more active, especially for those individuals who are prone to eat in excess after physical activity.

Recalled and momentary virtual portions created of snacks predict actual intake under laboratory stress condition.

Virtual portion tasks have been used to predict food intake in healthy individuals, severity of illness in individuals with anorexia nervosa, and weight loss in bariatric surgery patients. Whether portion creation in response to a recalled interpersonal stress ("recalled stress portions") could be used as a proxy for ad lib intake, after a stressor, remains untested, and the mechanism supporting this relationship is unclear. The present study's goals were: 1) to validate virtual portion tasks as proxies for actual food intake in a stressful context and 2) to test a causal pathway in which these virtual stress portions predict ad lib intake after stress. We proposed that this relationship is mediated by virtual portions created the moment after laboratory stress or rest manipulation (momentary portions), and before the participant actually ate food. At screening, 29 healthy undergraduate white women created virtual portions of eight snacks (apples, olives, potato chips, pretzels, caramel popcorn, milk chocolate) that they typically eat and also portions they recall eating in response to a stressful interpersonal situation. In addition, after a Trier Social Stress Test, or a rest period, on separate days in counterbalanced order, participants created 'momentary' virtual portions of the same snacks presented during screening, and then were given potato chips, mini golden Oreos, and M&Ms to eat. Recalled stress (b = 0.07 ± 0.02, p = 0.003), and momentary stress (b = 0.12 ± 0.02, p = 0.00001), portions of milk chocolate accounted for 29% and 51%, respectively, of the variance in ad lib stress intake of M&Ms. Typical (b = 0.15 ± 0.07, p = 0.03), and momentary rest (b = 0.21 ± 0.06, p = 0.002), portions of chips accounted for 16% and 31%, respectively, of the variance in ad lib rest intake of chips. The causal pathway from recalled stress portion to ad lib stress snack intake was completely mediated by momentary stress portion for milk chocolate and M&Ms (ß = 0.04 ± 0.02, z = 2.4, p = 0.0154). These findings illustrate the planning and recall components of eating in response to stress, but not necessarily under rest conditions. This recalled stress virtual portion paradigm has clinical and research value in that it can detect those who overconsume in response to stress.

Reliability and responsiveness of virtual portion size creation tasks: Influences of context, foods, and a bariatric surgical procedure.

Food portion size influences energy intake and sustained high-energy intake often leads to obesity. Virtual portion creation tasks (VPCTs), in which a participant creates portions of food on a computer screen, predict intake in healthy individuals. The objective of this study was to determine whether portions created in VPCTs are stable over time (test-retest reliability) and responsive to factors known to influence food intake, such as eating contexts and food types, and to determine if virtual portions can predict weight loss. Patients with obesity scheduled for bariatric surgery (n = 29), and individuals with a normal BMI (18.5-24.9 kg/m2, controls, n = 29), were instructed to create virtual portions of eight snack foods, which varied in energy density (low and high) and taste (sweet and salty). Portions were created in response to the following eating situations, or "contexts": What they would a) eat to stay healthy (healthy), b) typically eat (typical), c) eat to feel comfortably satisfied (satisfied), d) consider the most that they could tolerate eating (maximum), and e) eat if nothing was limiting them (desired). Tasks were completed before, and 3 months after, surgery in patients, and at two visits, 3 months apart, in controls. Body weight (kg) was recorded at both visits. Virtual portions differed significantly across groups, visits, eating contexts, energy densities (low vs. high), and tastes (sweet vs. salty). Portions created by controls did not change over time, while portions created by patients decreased significantly after surgery, for all contexts except healthy. For patients, desired and healthy portions predicted 3-month weight loss. VPCTs are replicable, responsive to foods and eating contexts, and predict surgical weight loss. These tasks could be useful for individual assessment of expectations of amounts that are eaten in health and disease and for prediction of weight loss.

Caregiver Influences on Eating Behaviors in Young Children: A Scientific Statement From the American Heart Association.

A substantial body of research suggests that efforts to prevent pediatric obesity may benefit from targeting not just what a child eats, but how they eat. Specifically, child obesity prevention should include a component that addresses reasons why children have differing abilities to start and stop eating in response to internal cues of hunger and satiety, a construct known as eating self-regulation. This review summarizes current knowledge regarding how caregivers can be an important influence on children's eating self-regulation during early childhood. First, we discuss the evidence supporting an association between caregiver feeding and child eating self-regulation. Second, we discuss what implications the current evidence has for actions caregivers may be able to take to support children's eating self-regulation. Finally, we consider the broader social, economic, and cultural context around the feeding environment relationship and how this intersects with the implementation of any actions. As far as we are aware, this is the first American Heart Association (AHA) scientific statement to focus on a psychobehavioral approach to reducing obesity risk in young children. It is anticipated that the timely information provided in this review can be used not only by caregivers within the immediate and extended family but also by a broad range of community-based care providers.

No evidence of flavour-nutrient learning in a two-week 'home exposure' study in humans.

Flavour-nutrient learning is robust in animals but remains elusive in humans. Recent evidence suggests flavour-nutrient learning may be more likely to occur with beverages that contain relatively few calories (compared to no calories), while others show that learned associations can influence satiation, without an effect on preference. The objective of this research was to determine whether acquired liking for a caloric drink could be observed in a 'home learning' context over 2 weeks, and whether it is impacted by viscosity. In combination, we also explored changes in learning relating to fullness and expected satiety. In a double-blind study, participants (N = 83; BMI = 23.3 kg/m2) were randomly allocated to one of four groups differing in either calories (0 kcal vs. 112.5 kcal) or viscosity (low vs. high) and consumed a novel-flavoured drink over 15 days. Measures of flavour (10 ml sample) and beverage liking, grip force (a measure of beverage reward value), fullness, and expected satiety were taken at the start and the end of the study. While the high-viscous beverages were less liked (M = 40.3 mm, SD = 24.7) than the low viscous beverages (M = 64.4 mm, SD = 15.3; p = .022), there was no evidence that repeated exposure to a calorie-containing beverage impacted subsequent liking for the flavour (p = .115) or for the beverage (p = .448), grip force (ps > .26), fullness, and expected satiety (ps > .12). Accordingly, we conclude that we found no evidence of flavour-nutrient learning and flavour-satiety learning. This null finding accords with previous observations indicating that humans do not acquire flavour-nutrient associations as readily as some non-human animals.

How does food-cue exposure lead to larger meal sizes?

Exposure to the sight and smell of food influences our momentary desire to consume it. This study explored the process by which cue exposure promotes greater consumption of food. Three hypotheses were explored, cue exposure: (i) increases the planned consumption of food; (ii) increases tolerance of larger portion sizes; (iii) arrests the development of satiety. Female participants (n 50) were each tested in two conditions. In a 'cue condition' they were exposed to the sight and smell of pizza for 60 s. Before and after this period they provided information about prospective and maximum tolerated portion sizes and their desire to eat pizza and other non-cued foods. Participants then consumed a fixed portion of pizza, rated their hunger and were finally offered ad libitum access to pizza. In the 'no-cue condition', cue exposure was replaced with a cognitive task. Cueing had little effect on tolerance of larger portion sizes or on hunger after consuming the fixed portion. Instead, it increased prospective pizza portion size and subsequent intake of pizza. Together, these results suggest that cueing increases the amount of food that people actively plan to eat. This plan is then executed, leading to greater intake. Pizza cueing also increased prospective portion size of other foods. Thus, contrary to previous reports, effects of exposure may generalize to other foods. Finally, we found evidence that restrained eaters are less 'cue reactive' than unrestrained eaters. In future, our approach might be adapted to consider whether heightened 'cue reactivity' represents a risk factor for obesity.