Gender differences in eating behavior and body weight regulation

Gender differences in food intake and selection first appear in adolescence. Men consume more calories than women, and the sexes have different eating styles, which indicate that women have been socialized to eat in a more feminine manner. Women experience more food-related conflict than men do, in that they like fattening foods but perceive that they should not eat them. Pressures to be thin are present in early adolescence, as noted by dieting behavior starting in very young girls. Women experience more dissatisfaction with their body weight and shape than men do. Sociocultural and psychological factors may be important in the etiology of eating disorders, which are much more prevalent in females than in males. Thus, further studies of gender differences in eating behavior will be important for understanding the etiology of eating and body-weight disorders and for designing gender-appropriate treatments.     

Activity-based anorexia: ambient temperature has been a neglected factor

Activity-based anorexia refers to the self-starvation of rats exposed to experimental conditions that combine restricted access to food with access to an activity wheel. This paper compares previous studies of this phenomenon in relation to the ambient temperatures (AT) that were employed. On this basis, and from some more direct evidence, we argue that AT is an important, but neglected, factor in activity-based anorexia research. More attention to AT is needed in future research, since its neglect threatens the validity of conclusions drawn from those studies. Furthermore, direct examination of the effect of AT on activity-based anorexia will allow a better understanding of the mechanisms underlying this phenomenon and the possible clinical implications for the treatment of human anorexia nervosa.     

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.     

The ecology of eating: smaller portion sizes in France Than in the United States help explain the French paradox

Part of the "French paradox" can be explained by the fact that the French eat less than Americans. We document that French portion sizes are smaller in comparable restaurants, in the sizes of individual portions of foods (but not other items) in supermarkets, in portions specified in cookbooks, and in the prominence of "all you can eat" restaurants in dining guides. We also present data, from observations at McDonald's, that the French take longer to eat than Americans. Our results suggest that in the domain of eating, and more generally, more attention should be paid to ecological factors, even though their mechanism of operation is transparent, and hence less revealing of fundamental psychological processes. Ironically, although the French eat less than Americans, they seem to eat for a longer period of time, and hence have more food experience. The French can have their cake and eat it as well.     

暴食症的诊断、治疗及其疗效

暴食症已成为目前世界上广泛流行的三大进食障碍之一,我国患者亦不在少数并有增加之势,但对暴食症的研究与治疗尚属起步阶段。文章回顾了暴食症的表征及其诊断技术,简要介绍了常见的三种治疗方法（即行为疗法、认知疗法及伴随症状改善法）,并讨论了影响暴食症疗效的诸个体因素。暴食症的诊断主要是根据美国精神疾病诊断与统计手册第四版（DSM-IV）、进食障碍检测评估表（EDE）（治疗者用）和患者用进食障碍检测问卷（EDE-Q）（患者用）,并结合过往病史和伴随症状。三类治疗方法在理论与操作层面各有倚重,均可收到一定治疗效果。但各疗法的效果与预后会因患者而异甚或迥乎相异,这是因为暴食症疗效还受到患者自身人格、社会和认知诸因素的影响,治疗者应根据特定患者选择适合该患者的疗法。     

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.

     

Preference and the specificity of goals

In this study, the authors examined (a) the effect of changes in the need to eat on expressed preferences for foods that are appropriate for different times of day and (b) whether that need is directed toward food in general or foods contextually appropriate to the time of day. Previous findings suggest that, when the goal is active relative to when it is inactive, items relevant to satisfying a goal increase in value but items unrelated to that goal decrease in value. The authors observed that, when people needed to eat, they sought foods that are contextually appropriate to the time of day of the study. Hence, the goal they sought to fulfill was narrower than seeking foods in general.     

Slim by design: Redirecting the accidental drivers of mindless overeating

We first choose what to eat and then we choose how much to eat. Yet as consumer psychologists, we understand food choice much better than food consumption quantity. This review focuses on three powerful drivers of food consumption quantity: 1) Sensory cues (how your senses react), 2) emotional cues (how you feel), and 3) normative cues (how you believe you are supposed to eat). These drivers influence consumption quantities partly because they bias our consumption monitoring—how much attention we pay to how much we eat. To date, consumption quantity research has comfortably focused on the first two drivers and on using education to combat overeating. In contrast, new research on consumption norms can uncover small changes in the eating environment (such as package downsizing, smaller dinnerware, and reduced visibility and convenience) that can be easily implemented in kitchens, restaurants, schools, and public policies to improve our monitoring of how much we eat and to help solve mindless overeating. It is easier to change our food environment than to change our mind.     

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.     

Adolescent Focused Psychotherapy for Adolescents with Anorexia Nervosa

The paper describes a manualized specific form on individually based developmentally oriented therapy for Anorexia Nervosa (AN) in adolescents. Adolescent focused psychotherapy for AN is derived from a self-psychology model and is designed to address key deficits in development associated with AN. Adolescents with AN are viewed as using food and weight to avoid negative affective states associated with adolescent developmental issues that they perceive as intolerable. To develop a more constructive coping style and improve self-efficacy, adolescent patients need to first learn to identify and define their emotions, and later, to tolerate emotions, particularly negative ones. In withdrawing from the environment and situations which provoke distress through self-starvation and preoccupations with food and weight, emotional and psychological development is arrested. Learning to identify and cope adaptively with emotions and developmental challenges presented by the environment form the key therapeutic targets of treatment. Specific therapeutic procedures, a case illustration and discussion of therapeutic rationale are also provided.     

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.     

Active regulation to be lean by rats with ventromedial hypothalamic lesions.

Adult female Long-Evans rats with direct-current electrolytic or radio-frequency thermocoagulatory lesions of the ventromedial hypothalamus (VMH) lived on pellet fragments or a powdered chow containing as much as 1.2% quinine sulfate by weight or lived in Skinner boxes with 45-mg Noyes pellets delivered contingent on fixed ratios (FR) of lever pressing up to FR 128. As had been found previously for intact rats, the body weights maintained by VMH rats were determined by the percentage of quinine sulfate in or the contingency of reinforcement of the food on which they lived. Even when the rats lived on highly adulterated or response-contingent food and were lean, they ate more of that food when the ambient temperature was reduced and less of that food during several weeks of forced feeding of eggnog by gavage. Weight maintenance in the cold and caloric compensation during forced feeding were as precise for VMH rats eating highly adulterated chow or Noyes pellets contingent on high fixed ratios of lever pressing as for VMH rats eating typical laboratory chow ad lib, even though the former rats at the time maintained weights no greater than intact rats and the latter rats at the time were grossly obese. Furthermore, regulation in the cold or during forced feeding was in general only a little less precise for the rats with lesions than for intact rats. It may be as characteristic of VMH rats that they eat to become lean and remain lean as that they eat to be obese. The diets of both intact and VMH rats in some manner determine the adiposities that rats will defend against caloric challenge.     

Food hoarding behaviour in the golden hamster (Mesocricetus auratus): Effects of body weight loss and hoard-size discrimination

Two experiments investigated some of the factors that influence food hoarding behaviour in the golden hamster (Mesocricetus auratus). In Experiment 1, hamsters given limited access to food failed to increase the amount of food they consumed at each meal. Instead, they exhibited a significant increase in the amount of food taken to hoard during the limited access period, and this permitted hamsters who were allowed to retain their hoard to maintain body weight at levels comparable to free-feeding controls. Hamsters that were not allowed to retain hoarded food rapidly lost body weight. There was also an inverse correlation between body weight and amount of food taken to hoard in all hamsters given limited access to food, suggesting that body weight loss was one factor directly related to increased hoarding during periods of limited food accessibility. Experiment 2 investigated the effect of hoard-size discrimination on food hoarding in hamsters by artificially manipulating hoard size. The results suggested that hoarding behaviour could be influenced by artificially depleting and repleting the hoard, and this factor appears to influence hoarding in the absence of any significant changes in body weight. These results are discussed in relation to the kinds of adaptive feeding strategies that hamsters may utilize in their natural environment.     

Common regulation of feeding and mating in Aplysia fasciata: pheromones released by mating and by egg cordons increase feeding behavior.

We examined whether pheromones released by reproductive behaviors (mating and egg-laying) affect feeding behavior. A preliminary experiment demonstrated that the quantity of food eaten can be used to measure the effects of pheromones on feeding. Using this measure, we then showed that Aplysia that were prevented from mating, but that were in the same aquarium as mating conspecifics, eat more food than do Aplysia in a medium lacking mating animals. Mating and feeding were not temporally correlated, indicating that pheromones released by mating probably do not initiate feeding, but rather modulate feeding after it has begun. Aplysia that were in the same aquarium as freshly deposited egg cordons also ate more than did animals in a medium lacking eggs.     

Conspecific aggression influences food carrying: Studies on a wild population of Rattus norvegicus

Laboratory rats, like many other animal species, transport food. Their behavior is influenced by factors such as food size, the time required to eat, travel distance, travel difficulty, and the availability of cover, etc. Recent versions of optimal foraging theory suggest that species that display such behavioral patterns do so in order to minimize risk to predation while at the same time maximizing food gain. Nevertheless, it is not clear that this explanation applies to rats, nor is it easy to investigate this problem in a laboratory. The results of the present study on urban feral rats show that their food handling behavior is similar to that of domestic rats. The results also suggest that food carrying can serve defensive as well as communicative functions. Aggression around food sources was high. Smaller rats always carried food and some large rats infrequently carried food, suggesting that the food carrying by smaller, subordinate rats may help them avoid conspecific aggression. The rats also vigorously attempted to steal food that was carried home by conspecifics. This result suggests that food carrying can redistribute food resources and inform conspecifics about food availability. The results demonstrate the utility of multilevel behavioral analysis and also demonstrate that for rats, food transport has functions other than predator avoidance, including avoidance of conspecific aggression and communication about food availability. © 1996 Wiley-Liss, Inc.     

Lifestyle differences between smokers,ex-smokers and non-smokers,and implications for their health

Abstract

Much evidence has been published in order to demonstrate that smoking cessation leads to a decrease in morbidity and mortality. Using data from the Health and Lifestyle Survey respondents were divided into three groups: smokers, ex-smokers and non-smokers and lifestyle characteristics such as diet and exercise were compared. Smokers were more likely to eat chips (French fries), fried food, butter and less likely to eat fresh fruit in winter, green vegetables and margarine high in polyunsaturated fats. Non-smokers were more likely than smokers and ex-smokers to take part in keepfit, jogging and swimming. Non-smokers in smoking households were more likely than non-smokers in non-smoking households to eat fried food, chips and butter and less likely to eat fruit in winter or margarine high in polyunsaturated fats. Results suggest that part of the assumed health benefits of smoking cessation are due to ex-smokers having a healthier diet than that of smokers.     

Incremental interpretation at verbs: restricting the domain of subsequent reference

Participants' eye movements were recorded as they inspected a semi-realistic visual scene showing a boy, a cake, and various distractor objects. Whilst viewing this scene, they heard sentences such as 'the boy will move the cake' or 'the boy will eat the cake'. The cake was the only edible object portrayed in the scene. In each of two experiments, the onset of saccadic eye movements to the target object (the cake) was significantly later in the move condition than in the eat condition; saccades to the target were launched after the onset of the spoken word cake in the move condition, but before its onset in the eat condition. The results suggest that information at the verb can be used to restrict the domain within the context to which subsequent reference will be made by the (as yet unencountered) post-verbal grammatical object. The data support a hypothesis in which sentence processing is driven by the predictive relationships between verbs, their syntactic arguments, and the real-world contexts in which they occur.     

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.     

Plasma glucose and insulin levels in monkeys anticipating feeding

To see whether plasma glucose or insulin changed in anticipation of feeding, we provided seven rhesus monkeys with four-hour access to food every other day. Blood was sampled before and during a 30-minute signal which ended with food availability and before and during a 30-minute signal which was not closely and reliably linked with food availability. Plasma insulin showed no evidence of conditioning. Plasma glucose was higher during the signal than prior to the signal in both experiments. This probably reflects the arousing nature of the signal rather than appetitive-associated learning. However, the differences, while statistically significant, were probably biologically trivial because they fall within the normal fluctuations of meal-fed monkeys. Under the conditions of this experiment, it appears that conditional changes in glucose and insulin do not reliably occur in monkeys anticipating access to food.     

Influencing food preferences of children by ‘if-then’ type instructions

Three experiments were conducted to examine the effects which ‘if-then’ instructions of the type ‘if you eat X’, then you will get Y, have on the evaluation of the foods addressed in the ‘if’ and the ‘then’ parts of the instructions, respectively. Based on research on intrinsic motivation it was hypothesized that liking for food X that one is induced to eat by means of ‘if-then’ instructions will be impaired, whereas liking for food Y offered as a reward for the consumption of X will be enhanced. Experiment 1 revealed an enhancement of liking effect for the ‘then’food lasting for at least six weeks, but no impairment of liking for the ‘if’ food. Experiment 2 explored the possibility of reducing children's dislike for foods by means of paradoxical ‘if-then’ instructions presenting the disliked food in the ‘then’ position as a reward for the consumption of another food. No significant effects were obtained in this study. Experiment 3 examined the effects of introducing yet unknown foods to children by means of ‘if-then’ instructions. Results revealed that liking for the new food is impaired when it is the ‘if’food, but is enhanced when it is offered in the ‘then’ position. Discussion is centered on the possibility that the effects of ‘if-then’ instructions are more pronounced in single trial compared to multi-trial treatment conditions.