Keri McCrickerd

Subtle changes in the flavour and texture of a drink enhance expectations of satiety

BackgroundThe consumption of liquid calories has been implicated in the development of obesity and weight gain. Energy-containing drinks are often reported to have a weak satiety value: one explanation for this is that because of their fluid texture they are not expected to have much nutritional value. It is important to consider what features of these drinks can be manipulated to enhance their expected satiety value. Two studies investigated the perception of subtle changes in a drink’s viscosity, and the extent to which thick texture and creamy flavour contribute to the generation of satiety expectations. Participants in the first study rated the sensory characteristics of 16 fruit yogurt drinks of increasing viscosity. In study two, a new set of participants evaluated eight versions of the fruit yogurt drink, which varied in thick texture, creamy flavour and energy content, for sensory and hedonic characteristics and satiety expectations.ResultsIn study one, participants were able to perceive small changes in drink viscosity that were strongly related to the actual viscosity of the drinks. In study two, the thick versions of the drink were expected to be more filling and have a greater expected satiety value, independent of the drink’s actual energy content. A creamy flavour enhanced the extent to which the drink was expected to be filling, but did not affect its expected satiety.ConclusionsThese results indicate that subtle manipulations of texture and creamy flavour can increase expectations that a fruit yogurt drink will be filling and suppress hunger, irrespective of the drink’s energy content. A thicker texture enhanced expectations of satiety to a greater extent than a creamier flavour, and may be one way to improve the anticipated satiating value of energy-containing beverages.

Sensory influences on food intake control: moving beyond palatability

The sensory experience of eating is an important determinant of food intake control, often attributed to the positive hedonic response associated with certain sensory cues. However, palatability is just one aspect of the sensory experience. Sensory cues based on a foods sight, smell, taste and texture are operational before, during and after an eating event. The focus of this review is to look beyond palatability and highlight recent advances in our understanding of how certain sensory characteristics can be used to promote better energy intake control. We consider the role of visual and odour cues in identifying food in the near environment, guiding food choice and memory for eating, and highlight the ways in which tastes and textures influence meal size and the development of satiety after consumption. Considering sensory characteristics as a functional feature of the foods and beverages we consume provides the opportunity for research to identify how sensory enhancements might be combined with energy reduction in otherwise palatable foods to optimize short‐term energy intake regulation in the current food environment. Moving forward, the challenge for sensory nutritional science will be to assess the longer‐term impact of these principles on weight management.

Does modifying the thick texture and creamy flavour of a drink change portion size selection and intake

Previous research indicates that a drinks sensory characteristics can influence appetite regulation. Enhancing the thick and creamy sensory characteristics of a drink generated expectations of satiety and improved its actual satiating effects. Expectations about food also play an important role in decisions about intake, in which case enhancing the thick and creamy characteristics of a drink might also result in smaller portion size selection. In the current study forty-eight participants (24 female) completed four test days where they came into the laboratory for a fixed-portion breakfast, returning two hours later for a mid-morning drink, which they could serve themselves and consume as much as they liked. Over the test days, participants consumed an iso-energetic drink in four sensory contexts: thin and low-creamy; thin and high-creamy; thick and low-creamy; thick and high-creamy. Results indicated that participants consumed less of the thick drinks, but that this was only true of the female participants; male participants consumed the same amount of the four drinks regardless of sensory context. The addition of creamy flavour did not affect intake but the thicker drinks were associated with an increase in perceived creaminess. Despite differences in intake, hunger and fullness ratings did not differ across male and female participants and were not affected by the drinks sensory characteristics. The vast majority of participants consumed all of the drink they served themselves indicating that differences in intake reflected portion size decisions. These findings suggest women will select smaller portions of a drink when its sensory characteristics indicate that it will be satiating.

Children's familiarity with snack foods changes expectations about fullness

BACKGROUND Palatability is regarded as a major determinant of childrens energy intake. However, few studies have considered nonhedonic beliefs about foods. In adults, there is emerging evidence that expectations about the satiating properties of foods are an important determinant of meal size, and these beliefs are learned. OBJECTIVE We measured and quantified childrens expected satiation across energy-dense snack foods by using a method of adjustment. Participants changed a comparison-food portion (pasta and tomato sauce) to match the satiation that they expected from a snack food. We predicted that children who were especially familiar with snack foods would expect the foods to generate greater satiation and that children who were unfamiliar with snack foods would match expected satiation on the basis of the physical characteristics (perceived volume) of the foods. DESIGN Seventy 11- to 12-y-old children completed measures of expected satiation, perceived volume, familiarity, and liking across 6 snack foods. RESULTS As anticipated, familiarity and expected satiation were positively related (r = 0.37, P = 0.002), and this association remained after liking was controlled for. Furthermore, expected-satiation and perceived-volume judgments were more dissimilar as familiarity with the foods increased. CONCLUSIONS Our findings highlight the role of learning in shaping childrens beliefs about the postingestive effects of the consumption of foods; children who ate the foods more often expected them to deliver greater satiation. Furthermore, our findings suggest that, in the absence of prior experience, children rely on a foods physical characteristics (a less-complex strategy) when they judge expected satiation. This trial was registered at clinicaltrials.gov as NCT01403753.

Fluid or Fuel? The Context of Consuming a Beverage Is Important for Satiety

Energy-containing beverages have a weak effect on satiety, limited by their fluid characteristics and perhaps because they are not considered ‘food’. This study investigated whether the context of consuming a beverage can influence the satiating power of its nutrients. Eighty participants consumed a lower- (LE, 75 kcal) and higher-energy (HE, 272 kcal) version of a beverage (covertly manipulated within-groups) on two test days, in one of four beverage contexts (between-groups): thin versions of the test-drinks were consumed as a thirst-quenching drink (n = 20), a filling snack (n = 20), or without additional information (n = 20). A fourth group consumed subtly thicker versions of the beverages without additional information (n = 20). Lunch intake 60 minutes later depended on the beverage context and energy content (p = 0.030): participants who consumed the thin beverages without additional information ate a similar amount of lunch after the LE and HE versions (LE = 475 kcal, HE = 464 kcal; p = 0.690) as did those participants who believed the beverages were designed to quench-thirst (LE = 442 kcal, HE = 402 kcal; p = 0.213), despite consuming an additional 197 kcal in the HE beverage. Consuming the beverage as a filling snack led participants to consume less at lunch after the HE beverage compared to the LE version (LE = 506 kcal, HE = 437 kcal; p = 0.025). This effect was also seen when the beverages were subtly thicker, with participants in this group displaying the largest response to the beverage’s energy content, consuming less at lunch after the HE version (LE = 552 kcal, HE = 415 kcal; p<0.001). These data indicate that beliefs about the consequences of consuming a beverage can affect the impact of its nutrients on appetite regulation and provide further evidence that a beverage’s sensory characteristics can limit its satiating power.

Consistency of Eating Rate, Oral Processing Behaviours and Energy Intake across Meals

Faster eating has been identified as a risk factor for obesity and the current study tested whether eating rate is consistent within an individual and linked to energy intake across multiple meals. Measures of ad libitum intake, eating rate, and oral processing at the same or similar test meal were recorded on four non-consecutive days for 146 participants (117 male, 29 female) recruited across four separate studies. All the meals were video recorded, and oral processing behaviours were derived through behavioural coding. Eating behaviours showed good to excellent consistency across the meals (intra-class correlation coefficients > 0.76, p < 0.001) and participants who ate faster took larger bites (β ≥ 0.39, p < 0.001) and consistently consumed more energy, independent of meal palatability, sex, body composition and reported appetite (β ≥ 0.17, p ≤ 0.025). Importantly, eating faster at one meal predicted faster eating and increased energy intake at subsequent meals (β > 0.20, p < 0.05). Faster eating is relatively consistent within individuals and is predictive of faster eating and increased energy intake at subsequent similar meals consumed in a laboratory context, independent of individual differences in body composition.

Eating in the absence of hunger: Stability over time and associations with eating behaviours and body composition in children

BACKGROUND/OBJECTIVES Eating in the absence of hunger (EAH) has been linked to obesity in adults and children. This study examined the stability of EAH in children between 4.5 and 6 years old, and associations with energy intake and portion selection, as well as cross-sectional and prospective associations with body composition. METHODS The participants were 158 boys and girls from the Growing Up in Singapore Towards healthy Outcomes cohort. At ages 4.5 and 6 years old children were provided lunch ad libitum, and immediately afterwards were exposed to palatable snacks to measure energy intake in the absence of hunger. At age 6 children completed an additional computer-based task to measure ideal portion size, where they selected pictures of the portions they would like to eat across eight foods. Measures of anthropometry (height/weight/skinfolds) were collected at both ages. RESULTS Children who consumed energy during the EAH task at age 4.5 years were 3 times more likely to also do so at age 6 years. Children with high EAH intakes at age 4.5 years had high EAH intakes at age 6, highlighting stability of this behaviour over time. Energy consumed at lunch was unrelated to energy consumed during the EAH task, but children who ate in the absence of hunger cumulatively consumed more energy over lunch and the EAH task. Children who showed EAH tended to select larger ideal portions of foods during the computer task. EAH was not associated with measures of body composition. CONCLUSIONS EAH is a stable behavioural risk factor for increased energy intake, but was not associated with body composition in this cohort. The majority of children ate in the absence of hunger, suggesting that interventions aimed at reducing responsiveness to external food cues could help to reduce energy intakes. Trial Registry Number: NCT01174875; https://clinicaltrials.gov/.

Oral processing behaviours that promote children's energy intake are associated with parent-reported appetitive traits: Results from the GUSTO cohort

Oral processing behaviours associated with faster eating rates have been consistently linked to increased energy intakes, but little is known about their links to childrens appetitive traits. This study used the Child Eating Behaviour Questionnaire (CEBQ) to explore cross-sectional and prospective associations between parent-reported appetitive traits and observed oral processing behaviours. Participants were 195 children from the Growing Up in Singapore Towards healthy Outcomes cohort, who participated in a video-recorded ad libitum lunch at 4.5 (Time 1) and 6 years (Time 2). Their mothers completed the CEBQ around the same time points. Childrens bites, chews and swallows were coded, and used to calculate their eating rate, bite size, chews per bite, chew rate, oral exposure time and oral exposure per bite. At Time 1, children with higher scores in slowness in eating had lower eating and chew rates. At Time 2, higher scores for food enjoyment and lower for satiety responsiveness, slowness in eating, and food fussiness were linked with higher eating rates and greater energy intakes (r > 0.16, p < 0.05). Post-hoc analyses revealed that these associations were moderated by BMI and only present among children with higher BMI. Faster eating rates mediated the associations between greater food enjoyment, lower slowness in eating, lower food fussiness and higher intakes of energy. Children with higher slowness in eating scores had lower increases in eating rates over time, and children with higher BMI who had greater food enjoyment and food responsiveness scores had greater increases in eating rates over time. The findings suggest that oral processing behaviours linked with increased obesity risk may be underpinned by appetitive traits and may be one of the behavioural pathways through which these appetitive traits influence energy intakes.

Food or fluid? The context of consuming a beverage influences satiety

Energy-containing beverages are reported to have a weak effect on satiety, limited by their fluid characteristics and because, unlike soups, they may not be considered ‘food’. This study investigated whether thinking of a beverage as food can improve the satiating power of its nutrients, compared to enhancing oro-sensory cues. Eighty participants consumed a lower(LE, 75 kcal) and higherenergy (HE, 272 kcal) version of a beverage on two test days, in one of four contexts: thin versions of the test-drinks were consumed as a thirst-quenching drink, a filling snack, or without additional information. A fourth group consumed subtly thicker versions of the drinks without additional information. Lunch intake 60minutes later depended on the beverage’s context and it’s covertly manipulated energy content: participants who previously consumed the thin beverages without additional information or with the belief that they were designed to quench-thirst ate a similar amount of lunch after the LE and HE versions, despite consuming 197 kcal in the HE beverage. Consuming the beverage as a filling snack led participants to significantly reduce lunch intake after the HE compared to the LE beverage. This effect was also seen when the beverages were subtly thicker, with participants in this group displaying the largest reduction in lunch intake after the HE version. These results indicate that satiety-relevant oro-sensory cues are important for satiety, but suggest that in the absence of these enhancements the satiating power of energy-containing beverages could be improved if consumers were encouraged to consider these products as food rather than just fluid.