Imitation of mother’s inappropriate food preference in weanling kittens

Experiments were performed on four mother cats and their 22 kittens from 7 litters. Each mother was trained to eat banana or mashed potato in the presence of meat pellets in order to get a hypothalamic stimulation reward. Eighteen of twenty-two weanling kittens which accompanied the mother during the session imitated the mother in eating banana or potato and ignored meat pellets. The imitation of the mother started not earlier than at 35 days of age and in most kittens (10 of 18) began between 49 and 56 days of age. The kittens which ate banana or potato with the mother also ate that food when tested alone after weaning at 9 to 27 weeks of age, either during 10 min sessions in the experimental compartment or during 24 hr tests in the home compartment. When banana was offered to 9 control 13–23 week old kittens (of three other mothers) who never before had eaten that food or had seen their mother eat it, 8 of them did not consume banana during three 24 hr tests. Some consumption, however, occurred in the ninth kitten during the third of these tests. It has been concluded that weanling kittens in the period of transition from maternal to independent feeding tend to imitate the mother in food preferences, even if the food chosen by the mother is unusual for their species. The food preferences acquired through the imitation of the mother may influence the food preferences at the later stages of life.     

Lack of interference in long-term memory for socially learned food preferences in rats (Rattus norvegicus)

Outside the laboratory, rats (Rattus norvegicus) are likely both to interact with several conspecifics that have eaten various foods and to eat a variety of foods themselves before they encounter any particular food for which they have a socially enhanced preference. Here the authors examine the stability of rats' socially learned food preferences following 6 days of potentially disruptive ingestive experiences. The authors found that 6 days of (a) eating unfamiliar foods, (b) interacting with demonstrators that had eaten unfamiliar foods, or (c) both eating unfamiliar foods and interacting with demonstrators that had eaten those foods had no measurable effect on rats' socially learned food preferences. The stability of socially enhanced food preferences over time and despite potentially disruptive experiences is consistent with the view that social learning about foods is an important determinant of the food choices of free-living Norway rats.     

Sensory-specific satiety is intact in amnesics who eat multiple meals

What is the relationship between memory and appetite? We explored this question by examining preferences for recently consumed food in patients with amnesia. Although the patients were unable to remember having eaten, and were inclined to eat multiple meals, we found that sensory-specific satiety was intact in these patients. The data suggest that sensory-specific satiety can occur in the absence of explicit memory for having eaten and that impaired sensory-specific satiety does not underlie the phenomenon of multiple-meal eating in amnesia. Overeating in amnesia may be due to disruption of learned control by physiological aftereffects of a recent meal or to problems utilizing internal cues relating to nutritional state.     

What Causes Humans to Begin and End A Meal? A Role for Memory for What Has Been Eaten, as Evidenced by A Study of Multiple Meal Eating in Amnesic Patients

Although many factors have been proposed and studied as causes of onset and termination of meals by humans, little attention has been paid to memory for what has previously been eaten. We propose that a principal determinant of meal onset and cessation in humans is memory of when a last meal was eaten and how much was consumed. Knowledge that one has just eaten a culturally defined complete meal may be sufficient grounds for refusal of further food. This hypothesis was tested by studying two densely amnesic patients who had almost no explicit memory for events that occurred more than a minute ago, and who, in particular, usually failed to remember that they had just eaten a meal. Both patients (on three occasions each) readily consumed a second lunch when it was offered 10 to 30 min after completion of the first meal, and usually began to consume a third meal when it was offered 10 to 30 min after completion of the second meal. These findings suggest that memory for what has recently been eaten is a substantial contributor to the onset or cessation of eating of a meal.     

Control of the behavior of schizophrenic patients by food

Operant-conditioning principles using food as a reinforcer were applied to control the behavior of 45 chronic schizophrenic patients. The investigation was conducted in a psychiatric ward in which there was 24-hr environmental control.

In order to use food as a reinforcer for controlling psychotic behavior, it was necessary first to deal with the eating deficits in the patients. Approximately 50% of the ward population was selected because of a history of refusal to eat. Their refusal to eat had remained relatively unaffected by one or more of these treatments: spoonfeeding, tubefeeding, intravaneous feeding, and electroshock. These treatments were discontinued, and the patients were left alone at mealtimes. The results show that social reinforcement in such forms as coaxing, persuading, and feeding the patient tend to shape patients into eating problems so they are conditioned to eat only with assistance. When refusal to eat was no longer followed by social reinforcement, the patients soon started eating unassisted. When access to the dining room was made dependent upon a chain of responses including a motor and social component, all patients learned these responses.

     

Social interaction modifies learned aversions, sodium appetite, and both palatability and handling-time induced dietary preference in rats (Rattus norvegicus)

In a series of four experiments, I examined the extent to which socially transmitted diet preference could counteract the effects of a learned aversion (Experiment 1), a palatability-based diet preference (Experiment 2), a polyethylene glycol 20,000-induced sodium appetite (Experiment 3), and a handling-time induced dietary preference (Experiment 4). I found that rats poisoned after eating a novel diet ate very substantial amounts of the averted diet following interaction with conspecifics that had eaten the averted diet. Following interaction with conspecifics that had eaten an unpalatable diet, rats offered a choice between palatable and unpalatable diets ate more than twice as much unpalatable diet as did controls lacking social experience. Sodium-deficient rats offered a choice between sodium-enriched and sodium-adequate diets ate less than half as much sodium-enriched diet, following interaction with conspecifics that had eaten sodium-adequate diet as did control rats lacking social experience. Rats offered a choice between isocaloric, roughly equipalatable foods with long and short handling times (e.g., sunflower seeds with and without shells) chose the food having the longer handling time after interacting with conspecifics eating that food. These findings suggest that social influence is a major factor in guiding diet selection by rats.     

Eating patterns and breakfast consumption in obese patients with binge eating disorder

This study examined eating patterns and breakfast consumption, and their relationships to weight and binge eating, in obese individuals with binge eating disorder (BED). One-hundred seventy-three consecutively evaluated men (n=46) and women (n=127) with BED were administered semi-structured interviews and self-report measures to assess the frequency of meals and snacks eaten, as well as binge eating and eating disorder features. Overall, those who consumed more frequent meals, particularly breakfast, and snacks, weighed less. Breakfast, which was eaten on a daily basis by less than half of participants (n=74; 43%), was the least frequently eaten meal of the day. Participants (n=56; 32%) who ate three meals per day weighed significantly less, and had significantly fewer binges, than participants (n=117; 68%) who did not regularly eat three meals per day. Thus, eating more frequently, having breakfast and consuming three meals every day, have potentially important clinical applications for the treatment of BED given that the effectiveness of specific interventions within treatments for BED are unknown, and that weight loss outcome for BED has been poor.     

The impact of manipulating personal standards on eating attitudes and behaviour

The relationship between perfectionism and eating disorders is well established and is of theoretical interest. This study used an experimental design to test the hypothesis that manipulating personal standards, a central feature of perfectionism, would influence eating attitudes and behaviour. Forty-one healthy women were randomly assigned either to a high personal standards condition (n = 18) or to a low personal standards condition for 24 h (n = 23). Measures of personal standards, perfectionism, and eating attitudes and behaviour were taken before and after the experimental manipulation. The manipulation was successful. After the manipulation, participants in the high personal standards condition ate fewer high calorie foods, made more attempts to restrict the overall amount of food eaten, and had significantly more regret after eating than those in the low personal standards condition. Other variables remained unchanged. It is concluded that experimental analyses can be of value in elucidating causal connections between perfectionism and eating attitudes and behaviour.     

Social facilitation of eating novel food in tufted capuchin monkeys (Cebus apella): input provided by group members and responses affected in the observer

Learning about food palatability from watching what conspecifics eat might be one of the advantages of group living. A previous study investigated whether group members' presence or eating activity account for social facilitation of eating of foods never previously tasted. Capuchins encountered novel colored foods when (1) alone (Alone condition) or (2) with group members visible in the nearby cage (Group-present condition) or (3) with group members present and eating a familiar food that had not been colored (Group+food condition). Social facilitation of eating occurred when group members were eating, despite the difference in color between the familiar food eaten by them and the novel food presented to the experimental subject. To clarify what subjects learnt from group members when social facilitation occurred, we further analyze here the data from the previous study. The number of visual exposures to the colored novel food (as a group member) correlated with increased consumption of that novel food when encountered later (as experimental subject). In contrast, the number of times that an individual fed on the familiar food (as a group member) did not decrease its consumption of novel food (as experimental subject). Therefore, capuchins (1) habituated to the colors of the novel foods, and (2) did not take into account that seeing group members eating a food does not provide information about the palatability of a differently colored food. Since social facilitation of eating occurs when foods do not match in color, at least in capuchins, social facilitation of eating should not be considered as a way of learning about a safe diet, but rather as a way of overcoming neophobia. Accepted after revision: 18 August 2001 Electronic Publication     

“Rare,ole, dirty snacks”: Some research notes on dirt eating

This paper investigates the topic of dirt‐eating. Using a review of the literature and intensive interviews conducted with twelve dirt eaters the study investigates dirt eaters from four focal points: 1) how each individual “got started” eating dirt; 2) where they get the dirt from; 3) when do they eat dirt and 4) why do they eat dirt. A discussion is offered on the future of the phenomenon and the implications of our findings.     

Effects of the presence of others on food intake: a normative interpretation

The authors review the effect of the presence of others on food intake. In social facilitation studies, people tend to eat more in groups than when alone. In modeling studies, the presence of others may facilitate or inhibit intake, depending on how much these other people eat. Studies of impression management demonstrate that people tend to eat less in the presence of others than when alone. The authors attempt to reconcile these divergent literatures by reference to a model of inhibitory norms that govern eating. In the presence of palatable food, and in the absence of clear signals of satiety, people look outward to cues from the environment to determine when to stop eating. Socially derived inhibitory norms can account for either increased or decreased intake in the presence of others, depending on how much the others eat and the extent to which one is eager to impress them.     

Incidental memory in dogs (Canis familiaris): adaptive behavioral solution at an unexpected memory test

Memory processing in nonhuman animals has been typically tested in situations where the animals are repeatedly trained to retrieve their memory trace, such as delayed matching to sample, serial probe recognition, etc. In contrast, how they utilize incidentally formed memory traces is not well investigated except in rodents. We examined whether domestic dogs could solve an unexpected test based on a single past experience. In Experiment 1, leashed dogs were led to 4 open, baited containers and allowed to eat from 2 of them (Exposure phase). After a walk outside for more than 10?min, during which time the containers were replaced with new identical ones, the dogs were unexpectedly returned to the site and unleashed for free exploration (test phase). Eleven out of 12 dogs first visited one of the containers from which they had not eaten. In Experiment 2, two containers had food in them, one had a nonedible object, and the last one was empty. Dogs visited all 4 containers and were allowed to eat one of the food rewards in the Exposure phase. In the test phase, unleashed dogs first visited the previously baited container from which they had not eaten significantly more often than chance. These results demonstrate that in an unexpected, test dogs may retrieve “what” and “where” information about seen (now invisible) items from incidental memory formed during a single past experience.     

The stress-eating paradox: Multiple daily measurements in adult males and females

Abstract

The stress-eating relationship was examined in a prospective study of 158 subjects who completed daily records of stress and eating for 84 days, yielding 16.188 person days of observation. Using both within-subjects and between-subjects analyses, individuals were much more likely to eat less than usual than to eat more than usual in response to stressful daily problems. The likelihood of eating more did not change as severity of stress increased, but the likelihood of eating less increased substantially. There were also clear gender differences. Males had a slight tendency to eat less than to eat more across all levels of stress, except at the highest level, where eating less occurred much more frequently. In females, the tendency to eat less as opposed to eating more emerged at middle levels of stress; at the highest level of stress, females were more than three times more likely to eat less than to eat more. Individual subjects were highly consistent over levels of stress in the direction of eating; 82% of the subjects were consistent in eating more or less over the majority of their stressful periods. These results show a clear effect of stress on eating, with eating less being the predominant response.     

Perceived Control, Drive for Thinness, and Food Consumption: Anorexic Tendencies as Displaced Reactance

Although loss of perceived control has been implicated in the development of eating disorders, previous research has not directly tested the relationship between perceived control and food consumption. This study investigated the hypothesis that individuals with anorexic tendencies react to low perceived control by restricting food intake as a means of regaining a sense of control. Forty female undergraduates who scored either low or high on the Drive for Thinness Scale (Garner & Olmsted, 1984) were led to believe they would be participating in two separate studies. Perceived control was experimentally manipulated such that half of the subjects experienced low control and half experienced high control over a social situation. Under the guise of a second experiment, subjects tasted breakfast cereals and completed measures relevant to eating and body image. Results showed that subjects who were high in drive for thinness (DT) who experienced low control ate less sweetened cereal and planned to eat less at dinner than high DT subjects who experienced high control. Low DT subjects were unaffected by the control manipulation. The results are discussed in terms of displaced reactance.     

The validity of dietary restraint scales: comment on Stice et al. (2004)

In 4 empirical studies, E. Stice, M. Fisher, and M. R. Lowe calculated the correlations between some widely used dietary restraint scales and food intake. Failing to find substantial negative correlations, they concluded that these scales were invalid. The current article challenges this conclusion. For one thing, there is some evidence that restrained eaters do eat less than do unrestrained eaters under controlled experimental conditions favoring self-control. Dietary restraint is also associated with tendencies toward disinhibition under conditions favoring loss of self-control; such disinhibition often masks (but does not invalidate) the construct of dietary restraint. For these and other reasons, the assessment of food intake at a single eating episode may not capture overall dietary restriction. Finally, how much one eats does not necessarily indicate whether one has eaten less than one desired to eat. The authors suggest that the existing restraint scales do in fact validly assess restriction of food intake, albeit in a more complex fashion than is evident from simple correlations in single episodes.     

A Failure to Obtain “Disinhibition”

The effects of removing the mothers from rat litters for an hour a day on days 3 to 9 (separation treatment) were evaluated against effects for litters where the mothers were removed and immediately replaced (disturbance) and undisturbed controls. There were no consistent differences between the groups in the open-field, but separated and disturbed litters were heavier than controls as adults and not different from one another. At weaning, separated litters were heavier and disturbed litters lighter than controls. The results are discussed in terms of the possible mechanisms underlying the effects of removing the mother, with emphasis on the comparison of mechanisms based on the specific absence of the mother from the litter with incidental disturbance effects or altered maternal responsiveness.     

Nothing gained: An explorative study of the long‐term effects of perceived maternal feeding practices on women's and men's adult BMI,body image dissatisfaction,and disordered eating

The objective of the studies presented here was the prediction of adult body mass index (BMI), body image dissatisfaction, and disordered eating from recalled maternal child feeding practices. Studies 1 and 2 sampled women from the community, and found that recalled childhood feeding practices predicted both current BMI and current disordered eating. Daughters whose mothers pressured them to eat as children had lower BMIs as adults. The more a mother was concerned about her daughter's weight as a child, and the more she restricted fatty food intake, the less the woman was satisfied with her current body image. Disordered eating of adult women was positively related to their mothers' restriction of their fatty food intake as children, and negatively related to the mothers' monitoring of their food intake as children. Combining the samples and subdividing them into four BMI intervals showed that the obese women were higher on all but one of the recalled maternal child feeding practices, as well as on disordered eating and body dissatisfaction. Age was found to be positively related to BMI and drive for thinness, but not to body dissatisfaction or disordered eating, with older women having higher BMI and more drive for thinness. Study 3 sampled adult men from the community and found that recalled maternal child feeding practices predicted adult BMI and disordered eating for men, as well as for women. Considerable sex differences were found for all study variables. Recollection of maternal child feeding practices may have a formative role in the development of body image, disordered eating, and BMI for men and women, even into adulthood.     

Counting bones: environmental cues that decrease food intake

At an all-you-can eat buffet in a sports bar, it was tested whether people would eat less if they knew how much they had already eaten. 50 graduate students (34 women; M age = 24.1 yr.) were seated at 21 tables randomly assigned to be bussed (leftover wings removed) or unbussed (wings left on table). The 31 students at the bussed tables ate more than those at the unbussed tables (7 wings vs. 5.5 wings), with the effect being stronger for men than women. In distracting eating environments, environmental cues may provide an effective means of reducing consumption. Implications for controlling alcohol intake were also noted.     

Two-year-old twins refuse to eat: A multidisciplinary approach to diagnosis and treatment

This round table addresses the diagnosis and treatment of feeding disorders and failure to thrive. It describes a family-centered approach by a multidisciplinary feeding disorders team, beginning with the screening evaluation by the team coordinator at intake, through the evaluations by various team members, the team meeting with the parents, the development of a treatment plan, to a 1-year follow-up after treatment. Both twins refused to eat textured food and were found to have a posttraumatic feeding disorder secondary to repeated gagging and choking on cereal and lumpy baby food. However, only one twin was engaged in a battle with the parents over eating and developed infantile anorexia associated with failure to thrive. The differential diagnosis and the specific treatment plans of these two feeding disorders characterized by food refusal are discussed.     

Slower eating rate reduces the food intake of men, but not women: implications for behavioral weight control

This study tested a central tenet of behavioral weight control: does slower eating rate reduce food intake and positively affect appetite ratings. This study used direct behavioral observation of participants' (n=48; 25BMI35) eating behavior using Universal Eating Monitors. Food intake and ratings of "desire to eat" (collected each minute during meals) were represented as a function of time. Based on an acclimation meal, participants' eating rate was modified by instructing them to eat a bite of food when prompted by a computer, which generated three types of meals: (1) baseline (eating rate was the same as the acclimation meal), (2) reduced-rate (eating rate was reduced by 50%), and (3) combined-rate (eating rate at the beginning of the meal was identical to that of the acclimation meal, subsequently eating rate was reduced by 50%). All meals were ad libitum. Slower eating rate during the reduced-rate and combined-rate meals resulted in less food intake compared to the baseline meal for men, but not women. Ratings of desire to eat, normalized for the amount of food consumed, were lower during the combined-rate meal for men and women. Thus, this basic premise of behavioral weight control was supported for men, but not for women.