The Selection of Foods by Rats, Humans, and Other Animals

Economic constraints on taste formation and the true cost of healthy eating

This article shows how an interaction between economic constraints and children's taste preferences shapes low-income families' food decisions. According to studies of eating behavior, children often refuse unfamiliar foods 8 to 15 times before accepting them. Using 80 interviews and 41 grocery-shopping observations with 73 primary caregivers in the Boston area in 2013-2015, I find that many low-income respondents minimize the risk of food waste by purchasing what their children like--often calorie-dense, nutrient-poor foods. High-income study participants, who have greater resources to withstand the cost of uneaten food, are more likely to repeatedly introduce foods that their children initially refuse. Several conditions moderate the relationship between children's taste aversion and respondents' risk aversion, including household-level food preferences, respondents' conceptions of adult authority, and children's experiences outside of the home. Low-income participants' risk aversion may affect children's taste acquisition and eating habits, with implications for socioeconomic disparities in diet quality. This article proposes that the cost of providing children a healthy diet may include the possible cost of foods that children waste as they acquire new tastes.

Stability of food neophobia from infancy through early childhood

The purpose of the present study was to examine whether rejection of novel foods during infancy predicted child behavioral and parent-reported neophobia at 4.5 years of age. Data for the present study were drawn from a longitudinal study following individuals (n = 82) from infancy through early childhood. At 6 and 12 months of age, the infants tasted a novel food (green beans, hummus, or cottage cheese) and their reactions were coded for rejection of the food (i.e. crying, force outs, or refusals). The children returned to the laboratory at 4.5 years of age and participated in a behavioral neophobia task where they were offered three novel foods (lychee, nori, and haw jelly) and the number of novel foods they tasted was recorded. Mothers also reported their own and their children's levels of food neophobia. Regression analyses revealed that rejection of novel foods at 6 months interacted with maternal neophobia to predict parent-rated child neophobia. Infants who exhibited low levels of rejection at 6 months showed higher levels of parent-rated neophobia when their mothers also showed high compared to low levels of neophobia. At 12 months of age, however, infants who exhibited high levels of rejection tended to have high levels of parent-rated neophobia regardless of their mothers' levels of neophobia. These results provide preliminary evidence that rejection of novel foods during infancy does predict neophobia during early childhood, but the results vary depending on when rejection of new foods is measured.

Mineral Acquisition from Clay by Budongo Forest Chimpanzees

Chimpanzees of the Sonso community, Budongo Forest, Uganda were observed eating clay and drinking clay-water from waterholes. We show that clay, clay-rich water, and clay obtained with leaf sponges, provide a range of minerals in different concentrations. The presence of aluminium in the clay consumed indicates that it takes the form of kaolinite. We discuss the contribution of clay geophagy to the mineral intake of the Sonso chimpanzees and show that clay eaten using leaf sponges is particularly rich in minerals. We show that termite mound soil, also regularly consumed, is rich in minerals. We discuss the frequency of clay and termite soil geophagy in the context of the disappearance from Budongo Forest of a formerly rich source of minerals, the decaying pith of Raphia farinifera palms.

Consumers' view on determinants to food satisfaction. A qualitative approach

The objective of this study was to gain a better understanding of the multiple determinants to food satisfaction from a consumer perspective. The study includes two focus groups with a total of 20 consumers varying in gender, age, employment and food interest. The results were divided into sections based on the main themes that arose from analysing the focus groups; i) sensory properties, ii) physical wellbeing, iii) expectations and desires, iv) the food context and v) comparison of the importance of the various determinants to satisfaction. Factors important for food satisfaction appear before as well as during and after intake. Before intake, the important factors are; expectations and desires based on memories about previous food experiences and the context in which the food is perceived. Physical wellbeing was mentioned important for the feeling of satisfaction, included in physical wellbeing is the experience of an appropriate energy level after intake. In general the sensory experience seems to be the primary determinant to satisfaction. The hedonic experience of eating could be enhanced by the social company and knowledge about the food inclusive health value and origin. Findings from the study will prospectively be used to develop a questionnaire. The questionnaire will be applied in case studies to measure factors influential in food satisfaction.

Author Reply: Grasping the Nebula: Inelegant Theories for Messy Phenomena

Grand unified theories of messy topics like emotion tend to fail at capturing all the important dimensions of their subject. Why is this? I take on this question while responding to commentaries.

A review of visual cues associated with food on food acceptance and consumption

Several sensory cues affect food intake including appearance, taste, odor, texture, temperature, and flavor. Although taste is an important factor regulating food intake, in most cases, the first sensory contact with food is through the eyes. Few studies have examined the effects of the appearance of a food portion on food acceptance and consumption. The purpose of this review is to identify the various visual factors associated with food such as proximity, visibility, color, variety, portion size, height, shape, number, volume, and the surface area and their effects on food acceptance and consumption. We suggest some ways that visual cues can be used to increase fruit and vegetable intake in children and decrease excessive food intake in adults. In addition, we discuss the need for future studies that can further establish the relationship between several unexplored visual dimensions of food (specifically shape, number, size, and surface area) and food intake.

Quinine sensitivity influences the acceptance of sea-buckthorn and grapefruit juices in 9- to 11-year-old children

The acceptance of novel foods by children is related to a number of factors, and differences in taste sensitivity may form some specific challenges. High sensitivity might be a barrier to the acceptance of sour/bitter products by children. This study investigated the effect of sensitivity to bitter, sour, sweet, and salty tastes on the acceptance of Nordic juices in 9- to 11-year-old children. A total of 328 children were subjected to two taste sensitivity tests for quinine, citric acid, sucrose, and NaCl. Their acceptance of six juices (carrot, rosehip, sea-buckthorn, lingonberry, grapefruit, and aronia) was measured. Bitter sensitivity was found to be significantly correlated to the intake of the sweet sea-buckthorn and lingonberry juices; the most bitter-sensitive children exhibited the highest intake of these juices. The opposite relationship was found for bitter sensitivity and the intake of the bitter grapefruit juice. Sour, sweet, and salt sensitivities did not affect the intake of any of the juices. Liking scores were not affected by sensitivity. In conclusion, bitter sensitivity appears to influence food intake in children to a greater extent than sour, sweet, or salt sensitivity. Bitter-sensitive children exhibited a reduced intake of grapefruit juice and a higher intake of sucrose-sweetened juices. Thus, bitter sensitivity might be a challenge in the acceptance of certain bitter foods.

Functional brain imaging of appetite

Obesity is a neurobehavioral disorder that results from a combination of overeating and insufficient physical activity. Finely tuned mechanisms exist to match food intake to caloric expenditure. However, faced with abundant inexpensive and calorie-dense foods, many humans (and perhaps most) have a tendency to consume beyond their caloric needs. The brain controls food intake by sensing internal energy-balance signals and external cues of food availability, and by controlling feeding behavior; it is therefore at the centre of the obesity problem. This article reviews the recent use of functional brain imaging in humans to study the neural control of appetite, and how the neural systems involved may cause vulnerability to overeating in the obesogenic environment.

Flavor network and the principles of food pairing

The cultural diversity of culinary practice, as illustrated by the variety of regional cuisines, raises the question of whether there are any general patterns that determine the ingredient combinations used in food today or principles that transcend individual tastes and recipes. We introduce a flavor network that captures the flavor compounds shared by culinary ingredients. Western cuisines show a tendency to use ingredient pairs that share many flavor compounds, supporting the so-called food pairing hypothesis. By contrast, East Asian cuisines tend to avoid compound sharing ingredients. Given the increasing availability of information on food preparation, our data-driven investigation opens new avenues towards a systematic understanding of culinary practice.

Fallback foods, eclectic omnivores, and the packaging problem

For omnivorous primates, as for other selective omnivores, the array of potential foods in their home ranges present a twofold problem: not all nutrients are present in any food in the requisite amounts or proportions and not all toxins and other costs are absent. Costs and benefits are inextricably linked. This so-called packaging problem is particularly acute during periods, often seasonal, when the benefit-to-cost ratios of available foods are especially low and animals must subsist on fallback foods. Thus, fallback foods represent the packaging problem in extreme form. The use of fallback foods by omnivorous primates is part of a suite of interconnected adaptations to the packaging problem, the commingling of costs and benefits in accessing food and other vital resources. These adaptations occur at every level of biological organization. This article surveys 16 types of potential adaptations of omnivorous primates to fallback foods and the packaging problem. Behavioral adaptations, in addition to finding and feeding on fallback foods, include minimizing costs and requirements, exploiting food outbreaks, living in social groups and learning from others, and shifting the home range. Adaptive anatomical and physiological traits include unspecialized guts and dentition, binocular color vision, agile bodies and limbs, Meissner's corpuscles in finger tips, enlargement of the neocortex, internal storage of foods and nutrients, and ability internally to synthesize compounds not readily available in the habitat. Finally, during periods requiring prolonged use of fallback foods, life history components may undergo changes, including reduction of parental investment, extended interbirth intervals, seasonal breeding or, in the extreme, aborted fetuses.

Specific social influences on the acceptance of novel foods in 2–5-year-old children

Social influences have been shown to be very important to overcome food neophobia in young children. However, there is no experimental evidence about whether social influences on food acceptance are specific, that is if models eating the same food as the child are more effective in promoting food acceptance than models eating a different food. We assessed children's behavior towards novel foods when an adult model (a) was not eating (Presence condition), (b) was eating a food of a Different color (Different color condition), and (c) was eating a food of the Same color (Same color condition). We tested 27 children (ages 2- to 5-years-old) recruited from The Pennsylvania State University day-care facilities. Results show that children accepted and ate their novel food more in the Same color condition than in the Different color and in the Presence conditions. Therefore, in young children food acceptance is promoted by specific social influences. These data indicate that children are more likely to eat new food if others are eating the same type of food than when others are merely present or eating another kind of food.

[Food allergy in the child: an exploratory study on the impact of the elimination diet on food neophobia]

OBJECTIVES

This study was designed to analyse the impact of an elimination diet in children with food allergy, and its perception by their parents on the later reticence of children to test unknown foods, food neophobia.

METHODS

The degree of food neophobia of children having outgrown their allergy (mean age, 7 years 2 months) was compared to that of a sibling (9 years 5 months) using a standardized scale and a questionnaire of food friendliness. Parents were also asked to fill in a questionnaire on the disease and its burden on the family.

RESULTS

Children having outgrown their allergy are more reluctant to test new foods than their non-allergic brother or sister, as shown by their scoring on the food neophobia scale and the number of unknown foods following the cure of the disease. Two factors increase the level of food neophobia, the distressing effect and the duration of the period elapsed until the diagnosis was made, as well as the distressing effect and the lack of variety in the meal preparation.

CONCLUSION

Food neophobia, a normal phase between 2 and 10 years, is worsened by the elimination diet required by food allergy, especially in case of late diagnosis and when the time elapsed before diagnosis and the preparation of meals were perceived as difficult to bear.

The Effect of Age on Death Disgust: Challenges to Terror Management Perspectives

Proponents of Terror Management Theory (TMT) argue that many facets of disgust serve to defend against existential anxiety accompanying cognizance of one's mortality. Because the passage of time brings death closer, this view predicts that the intensity of disgust elicited by reminders of death should increase with age. Skeptical of TMT, we conducted Internet-based studies using the instrument created by TMT proponents. Results reveal that age is negatively, not positively, correlated with death disgust sensitivity, a pattern consistent with adaptive habituation rather than terror management. The same result was obtained using in-person administration of the instrument in Costa Rica, a society characterized by attitudes toward death that differ from those of the U.S. Additional work in Costa Rica demonstrated that, contrary to TMT predictions, attention to one's own death need not increase disgust reactions to the body or its products. Both the evocative power of death stimuli and the negative effects of age on death disgust are consistent with the argument that disgust is an adaptation motivating disease avoidance rather than a psychodynamic defense mechanism.

Differences Between Golden Hamsters (Mesocricetus auratus) and Norway Rats (Rattus norvegicus) in Preference for the Sole Diet That They Are Eating

D. DiBattista (2002) reported that hamsters but not rats showed reduced preferences for the sole diet they had eaten for 10 days. In the current study, the authors fed Norway rats (Rattus norvegicus) a nutritious diet for either 3 or 10 days, then tested them either immediately or 1 or 3 days later. The authors found that like golden hamsters (Mesocricetus auratus), rats exhibited reduced preferences for a prefed diet but only if tested either immediately or 1 day after prefeeding, not if tested 3 days later (when D. DiBattista tested his hamsters). Rats and hamsters differed in the longevity, not the development, of reduced preferences for a palatable food eaten for several consecutive days. Such a response might aid dietary generalists in constructing balanced diets when no single available food is nutritionally adequate.

Flavor programming during infancy

OBJECTIVE

Although individuals differ substantially in their flavor and food preferences, the source of such differences remains a mystery. The present experimental study was motivated by clinical observations that early experience with formulas establishes subsequent preferences.

DESIGN

Infants whose parents had chosen to formula-feed them were randomized into 1 of 4 groups by the second week of life. One group was assigned to be fed a milk-based formula (Enfamil), whereas another was assigned to be fed (Nutramigen), a particularly unpleasant-tasting protein hydrolysate formula. The remaining groups were assigned to be fed Nutramigen for 3 months and Enfamil for 4 months; the timing of exposure differed between the groups. After 7 months of exposure, infants were videotaped on 3 separate days while feeding, in counterbalanced order, Enfamil, Nutramigen, and Alimentum, a novel hydrolysate formula.

RESULTS

For each of the 4 interrelated measures of behavior (intake, duration of formula feeding, facial expressions, and mothers' judgments of infant acceptance), previous exposure to Nutramigen significantly enhanced subsequent acceptance of both Nutramigen and Alimentum. Seven months of exposure led to greater acceptance than did 3 months.

CONCLUSIONS

The bases for clinical difficulties in introducing hydrolysate formulas during older infancy are clarified in this study. More broadly, variation in formula flavor provided a useful model for demonstrating experimentally the effects of long-term exposure differences on later acceptance. Such early variation, under more species-typical circumstances (eg, via exposure to different flavors in amniotic fluid and mothers' milk), may underlie individual differences in food acceptability throughout the life span.

Social and asocial cues about new food: cue reliability influences intake in rats

Dietary generalists often treat new foods with caution and may rely on social cues to identify new foods that are safe to eat. However, not all generalists show the same degree of caution, nor do they all rely on social cues to the same extent. The cue reliability approach (CRA) attempts to account for this variation by quantifying the costs and benefits of sampling a new food for the first time. The experiments reported here tested predictions of the CRA, and the results suggested that rats eat more new food when asocial cues predict that new foods will prove more profitable than familiar foods. The experimental results also suggested that rats are more likely to seek out social cues when asocial cues are unreliable.

Increasing children's acceptance of vegetables; a randomized trial of parent-led exposure

Despite considerable epidemiological evidence of the health benefits of a diet high in fruit and vegetables, consumption in pre-school children remains well below recommended levels. This study evaluated the effectiveness of an exposure-based intervention, carried out by parents in the home, in increasing children's liking for a previously disliked vegetable. 156 parents of 2-6 year old children were randomly assigned to Exposure, Information or Control groups after a pre-intervention taste test at which a 'target' vegetable was selected. Parents in the Exposure group gave their child a taste of this vegetable daily for 14 days, parents in the Information group were given nutritional advice and a leaflet, and parents in the Control group received no further intervention. All participants took part in a post-intervention taste test. Greater increases in liking, ranking and consumption of the 'target' vegetable from pre- to post-intervention occurred in the Exposure group than in either of the other two groups. Only the Exposure group showed significant increases across all three outcomes. It can be concluded that a parent-led, exposure-based intervention involving daily tasting of a vegetable holds promise for improving children's acceptance of vegetables. These findings suggest a parental advice strategy which could be disseminated directly to parents or by health professionals.