Self-reported measures of appetite in relation to verbal cues about many foods

In the present study a representative sample of students from a general college population were exposed to a list of written food cues and asked to rate each of the foods according to its nutritional value. Subjects who were exposed to the food list subsequently reported increases in hunger, desire to eat, and number of foods currently hungry for, as well as reduced fullness, compared to controls who were not exposed to the food list. Also, there was a trend for the food-cued subjects to report hunger for lower fat foods compared to the controls. The results are discussed in terms of previous research and suggestions for future research are provided.     

The Effects of a List of Food Items on Motivations to Eat in Dieters and Nondieters

A major health problem in our society is obesity, which is frequently caused by overeating or eating inappropriate foods. It has been suggested that the prevalences of food and food-related cues contribute to overeating and that dieters are particularly sensitive to food stimuli. In the present study, the influence of dieting was examined in a representative sample of college students who were exposed to a list of written food cues or who served as controls. The list of food cues increased motivation to eat in nondieting subjects, but did not appear to influence the appetites of dieters. It may be that dieters are more resistant to the effects of more subtle food cues, even when many cues are presented sequentially.     

Nutritional habits and motivations to eat after a palatable pre-load

A representative sample of college students was surveyed about nutritional habits and motivations to eat. Females were more likely to report dieting, being overweight, reading nutritional labels, eating healthy meals, as well as hungering for and consuming lower fat foods compared to males. Males reported a greater hunger for and consumption of candy bars compared to females. Thus, females may not be as ambivalent about eating sweet or higher fat foods as previously suggested. The experimental manipulation involved exposing subjects to either candy before the survey, candy with the survey, or just the survey with no candy exposure. Females exposed to the candy preload indicated an increased hunger for fruits and vegetables compared to female controls. Portions of this research have been presented at the 1999 annual meeting of the Eastern Psychological Association in Providence, RI. The authors would like to thank Mr. Steve Lukasik and Ms. Christie Piedmont for their assistance on this project.     

Nutritional habits and motivations to eat after a palatable pre-load

A representative sample of college students was surveyed about nutritional habits and motivations to eat. Females were more likely to report dieting, being overweight, reading nutritional labels, eating healthy meals, as well as hungering for and consuming lower fat foods compared to males. Males reported a greater hunger for and consumption of candy bars compared to females. Thus, females may not be as ambivalent about eating sweet or higher fat foods as previously suggested. The experimental manipulation involved exposing subjects to either candy before the survey, candy with the survey, or just the survey with no candy exposure. Females exposed to the candy preload indicated an increased hunger for fruits and vegetables compared to female controls. Portions of this research have been presented at the 1999 annual meeting of the Eastern Psychological Association in Providence, RI. The authors would like to thank Mr. Steve Lukasik and Ms. Christie Piedmont for their assistance on this project.     

Hash browns for breakfast,baked potatoes for dinner: Changes in food attitudes as a function of motivation and context

Two studies investigated whether participants' motivational state and the context in which attitude reports are made influence food attitudes. Specifically, these studies examined whether hunger and the time‐typicality of foods (i.e. match or mismatch between the time when a food is typically eaten and the time the attitude is reported) interact to influence reported attitudes. Study 1 suggests that hunger leads to more positive attitudes toward foods that are typically eaten at the time the attitude report is made (e.g. breakfast foods in morning) compared to foods not typically eaten at the time the attitude report is made (e.g. breakfast foods in evening). Study 2 replicates this time‐typical effect of hunger and suggests that time‐typical experience rather than general experience with foods is important for hunger induced attitude change. By demonstrating that food attitudes are influenced by motivational states and the match between when the attitude is reported and when it is typically encountered, the present studies extend previous attitude theory and research that has identified other contextual factors that influence attitude reports. Copyright © 2004 John Wiley & Sons, Ltd.     

Feast your eyes: hunger and trait reward drive predict attentional bias for food cues

Appraisal theories of emotion predict that the relevance of a stimulus to a person's needs and goals influences attentional allocation. We used a modified visual probe task to examine the influence of hunger and trait reward drive on food-related attentional bias. Both hunger and trait reward drive predicted degree of attentional "disengagement" from food images at short (100 ms), but not long (500, 2,000 ms) stimulus durations. Effects of hunger were found for both bland and appetizing foods, while effects of reward drive were restricted to appetizing foods. Our findings extend previous research showing delayed "disengagement" from threat-related stimuli, suggesting that both organismic- and goal-relevance are key biasing factors in attentional competition.     

Personal Theories of Hunger and Eating1

Recent research on hunger and eating has shown that (a) among individuals with adlibitum access to food, hunger and eating are not regulated by deviations in the body's energy resources from set-points, and (b) it is healthier for people to consume their daily caloric intake as several small snacks than as 3 large meals. People's beliefs about hunger and eating were assessed in 2 questionnaire studies. In Study 1, a large sample of undergraduates was surveyed; in Study 2, dietetics students, nursing students, medical students, dietitians, nurses, and doctors were surveyed. Both studies revealed that people's personal theories of hunger and eating were inconsistent with research findings in ways that could promote overconsumption. These results suggest that educational programs designed to modify the beliefs about hunger and eating of people suffering from problems of overconsumption and of health professionals who treat problems of overconsumption may increase the effectiveness of current treatment regimens.     

Salivation: an assessment of food craving?

The validity of salivation as a measure of hunger and food craving was examined. Previous studies examining the relationship between salivation, food cues, and self-reports of hunger and food craving reported inconsistent results. The present study, using a modification of the Strongin-Hinsie-Peck (SHP) test to measure salivation, examined these relationships with overweight subjects. Salivation measures were taken on 25 subjects in a weight-control program during three experimental conditions: baseline I, food exposure and baseline II. While food exposure significantly increased the amount of salivation as compared to baseline, salivation did not correlate with self-reports of hunger or food cravings. Significant correlations were found for salivation, age. sex, and body fat. Implications of these results are discussed.     

Hunger, eating, and ill health

Humans and other warm-blooded animals living with continuous access to a variety of good-tasting foods tend to eat too much and suffer ill health as a result--a finding that is incompatible with the widely held view that hunger and eating are compensatory processes that function to maintain the body's energy resources at a set point. The authors argue that because of the scarcity and unpredictability of food in nature, humans and other animals have evolved to eat to their physiological limits when food is readily available, so that excess energy can be stored in the body as a buffer against future food shortages. The discrepancy between the environment in which the hunger and eating system evolved and the food-replete environments in which many people now live has led to the current problem of overconsumption existing in many countries. This evolutionary perspective has implications for understanding the etiology of anorexia nervosa.     

Effects of imagining eating favorable and unfavorable foods on gastric motility indexed by electrogastrographic (EGG) activities

The purpose of this study was to investigate the effects of imagining favorable or unfavorable foods on the amplitude of EGG recordings. 40 subjects were assigned to Favorable food and Unfavorable food groups in which they were asked to imagine eating a list of favorable foods or unfavorable foods. Subjects sat in a chair for 16 min, of baseline measurement prior to the 16 min. of food imagining. Electrogastrographic (EGG) activities were recorded continuously throughout. Using Fast Fourier Transform analysis, the spectral power of EGG activity of 3 cycles per minute (cpm) was calculated, and the ratios of EGG 3 cpm spectral power for the period of food imagining and baseline were obtained. The EGG amplitude at 3 cpm during imagining eating a list of unfavorable food was significantly lower than that of the baseline period and the EGG ratio between the food-imagining and baseline periods was significantly lower in the Unfavorable group than in the Favorable food group. It appears that imagining eating unfavorable food significantly inhibited gastric motility as indexed by decreased power of EGG activities at 3 cpm.     

Serotonin enhances the impact of health information on food choice

Serotonin has been implicated in promoting self-control, regulation of hunger and physiological homeostasis, and regulation of caloric intake. However, it remains unclear whether the effects of serotonin on caloric intake reflect purely homeostatic mechanisms, or whether serotonin also modulates cognitive processes involved in dietary decision making. We investigated the effects of an acute dose of the serotonin reuptake inhibitor citalopram on choices between food items that differed along taste and health attributes, compared with placebo and the noradrenaline reuptake inhibitor atomoxetine. Twenty-seven participants attended three sessions and received single doses of atomoxetine, citalopram, and placebo in a double-blind randomised cross-over design. Relative to placebo, citalopram increased choices of more healthy foods over less healthy foods. Citalopram also increased the emphasis on health considerations in decisions. Atomoxetine did not affect decision making relative to placebo. The results support the hypothesis that serotonin may influence food choice by enhancing a focus on long-term goals. The findings are relevant for understanding decisions about food consumption and also for treating health conditions such as eating disorders and obesity.     

The role of pre-exposure to novel food tastes in activity-based conditioned taste avoidance

Rats were given differential exposure to three distinct and novel foods. One of these foods was exposed for 7 days; another for 2 days, and the last was not exposed. Next, half of the rats received six daily sessions in which a compound of the three flavors was followed by opportunities to run in wheels. The other rats received the food compound but without wheel running. On the next day, all rats were given a choice among the three food flavors presented concurrently in separate dishes. When the compound food had been followed by wheel running, rats ate little of the food given no pre-exposure, more of the food given 2 days of pre-exposure, and considerably more of the food given 7 days of pre-exposure. In comparison, rats who did not receive an opportunity to run ate equal and moderate amounts of the three foods. The results suggest that pre-exposure to a food’s taste produces latent inhibition that interferes with conditioned taste avoidance produced by pairing a taste (CS) with wheel running (US).     

What did I eat yesterday? Determinants of accuracy in 24-hour food memories

Large-scale diet-related epidemiological work relies on the quality of self-reported food consumption. As this epidemiological work forms the basis of knowledge of the relationship of diet to disease, it is essential that the self-reports of personal diet are understood. It is generally accepted that foods consumed are under-reported, even over as short a period as 24 hours. However, little is known about the potential systematic biases that may affect the quality of self-reported food intake. The current study examines the accuracy of memories of the consumption of snack foods eaten in the previous 24 hours and investigates factors that may bias these memories. All participants had previously participated in a randomized intervention trial to lower dietary fat intake to 20 per cent of calories. Fifty-six women (intervention and control) tasted eight snack foods in a laboratory setting. They were telephoned a day later and asked to recall the type of snack foods (M&Ms, pretzels, etc.) and the quantity of each food they consumed. Subjects in general under-reported the number of selections and the quantity of each item consumed. Women who accurately recalled an item, reported more liking for that item compared to those who forgot the item. Women currently maintaining a low-fat diet were less accurate in their recall of low-fat items than women on a high-fat diet. Low-fat eaters, however, may be slightly better at recalling how much of certain foods they consumed. Results have implications for survey research and understanding the psychological influences on reports of food consumption used in large-scale diet studies.     

Increasing variety of foods consumed by blending nonpreferred foods into preferred foods

A treatment with differential or noncontingent reinforcement and nonremoval of the spoon increased the acceptance of one or two of 16 foods for 2 participants with severe food refusal. These differential levels of acceptance were demonstrated empirically in an ABAB design in which A was the presentation of the accepted (preferred) foods and B was the presentation of foods the participants refused (nonpreferred foods). Subsequently, we implemented a blending treatment that consisted of mixing (blending) nonpreferred foods into preferred foods in various ratios (e.g., 10% nonpreferred/90% preferred, 20% nonpreferred/80% preferred). We then presented nonpreferred foods that had been exposed to blending to determine if consumption of nonpreferred foods would increase following the blending treatment. We also conducted periodic reversals in which we presented nonpreferred foods that had not been exposed to the blending treatment. Following initial implementation of the blending treatment, consumption was high for nonpreferred foods that had been blended and low for nonpreferred foods that had not been blended. Consumption increased for all foods (i.e., foods that had been exposed to blending and foods that had not been exposed to blending) after seven or eight foods had been exposed to the blending treatment. Thus, the variety of foods consumed by the participants increased from one or two to 16. These results are discussed in terms of stimulus fading, conditioned food preferences, and escape extinction. DESCRIPTORS: conditioned food preferences, food refusal, negative reinforcement, stimulus fading     

Learning and transfer of calorie information

This study compared generating information about food to viewing and verbally producing that information for learning and transfer. Specifically, during training, a list of food items was shown, and some participants generated either real calories (Experiment 1) or fabricated prices (Experiment 2) associated with those foods with feedback provided (seeding), some viewed and read aloud values provided (viewing), and others read aloud the names of the items with no values provided (control). All participants were tested immediately and 1 week later on both old and new foods. In both experiments, the seeding and viewing conditions showed more learning than the control condition, and only the experimental conditions showed transfer of learning from old to new foods, with advantages found for seeding over viewing only in some cases. The results are discussed in terms of the seeding, testing, generation, and production effects, as well as their applications to health and policy.     

Evaluating preference for and reinforcing efficacy of fruits and vegetables compared with salty and sweet foods

Children diagnosed with autism spectrum disorder are often more selective in their food preferences than their typically developing peers. Additionally, many preferred food selections have minimal nutritional value. We evaluated the preference for, and reinforcing efficacy of, fruits and vegetables compared with salty and sweet foods, which are often used as edible reinforcers. Multiple-stimulus preference assessments were conducted to identify preferred foods, and reinforcer assessments were conducted to determine the reinforcing efficacy of more preferred foods. Fruits and vegetables were sometimes preferred over salty or sweet foods and often functioned as reinforcers. Future research should incorporate fruits and vegetables into preference assessments when identifying putative reinforcers.     

Social Information Guides Infants' Selection of Foods

Two experiments investigated the influence of socially conveyed emotions and speech on infants' choices among food. After watching films in which two unfamiliar actresses each spoke while eating a different kind of food, 12-month-old infants were allowed to choose between the two foods. In Experiment 1, infants selected a food endorsed by a speaker of their native language who displayed positive affect over a food endorsed by a foreign-language speaker who displayed negative affect. In Experiment 2, both actresses displayed positive affect, but they spoke in different languages, and infants again selected the food associated with the speaker of their native language. The findings contrast with previous research in which infants and toddlers have shown little selectivity when presented with foods that differ in their intrinsic properties such as color, texture, and familiarity. Although infants may lack capacities for evaluating foods on their own, they do look to other people for guidance in food selection.     

Social transmission and memory of food preferences in pine voles (Microtus pinetorum)

The social transmission of food preferences is affected by factors including the length of time a preference is maintained. The authors investigated the social transmission of food preferences in pine voles (Microtus pinetorum) and whether food items had to be present for memory to persist. A demonstrator vole was fed cocoa-flavored food, a nonpreferred food. After interacting with a demonstrator vole, observer voles preferred cocoa-flavored food as compared with either naive voles that had not interacted with demonstrators or voles that had been exposed to odors. Observers retained this preference for 72 hr after interacting with an observer whether or not flavored foods were present. The ability to learn which food items are palatable and safe may benefit a generalist herbivore that has faced selection to avoid toxic baits.     

How emotions expressed by adults’ faces affect the desire to eat liked and disliked foods in children compared to adults

The aim of this study was to determine whether or not pleasure, neutrality, and disgust expressed by eaters in photographs could affect the desire to eat food products to a greater extent in children than in adults. Children of 5 and 8 years of age, as well as adults, were presented with photographs of liked and disliked foods. These foods were presented either alone or with an eater who expressed three different emotions: pleasure, neutrality, or disgust. Results showed that, compared with food presented alone, food presented with a pleasant face increased the desire to eat disliked foods, particularly in children, and increased the desire to eat liked foods only in the 5‐year‐old children. In contrast, with a disgusted face, the desire to eat the liked foods decreased in all participants, although to a greater extent in children, while it had no effect on the desire to eat the disliked foods. Finally, food presented with a neutral face also increased and decreased the desire to eat disliked and liked foods, respectively, and in each case more for the 5‐year‐olds than for the older participants. In sum, the facial expressions of others influence the desire to eat liked and disliked foods and, to a greater extent, in younger children.