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 unit size effect of indulgent food: How eating smaller sized items signals impulsivity and makes consumers eat less

In deciding how much to eat, people are influenced by environmental cues. The unit size of food (i.e. the number of units in which a given amount of food is divided) provides such a cue. Previous research showed that given equal caloric and volumetric content, smaller units of food tend to reduce food consumption. We propose that the unit size of food impacts intake as it influences perceptions of impulsiveness and appropriateness. Our analysis is based on three experimental studies, all employing between subject designs. When consuming similar amounts of chocolates in studies 1 (n?=?118) and 2 (n?=?124), both studies show that consumption of five small units of chocolates is considered to be more impulsive, excessive and less appropriate than consuming one large unit of chocolate. Results of a third study (n?=?165) indicate that about 23% less chocolate is eaten when it is presented in small unit size vs. a large unit size and this effect is mediated by perceptions of impulsivity. All three studies suggest that perceptions of impulsivity and excess eating while eating several smaller units of food compared to one large unit might be a key factor explaining consumption effects in earlier studies on this bias.     

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.     

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.     

Emotional eating moderates the relationship between implicit measures of attitudes and chocolate consumption

Emotional eaters tend to eat more when emotionally aroused and their food‐related actions are associated with lack of control. Two studies tested the hypothesis that implicit measures of attitudes would be more strongly associated with the dietary behaviour of emotional eaters. In both Study 1 (N = 32) and Study 2 (N = 101), participants completed the DEBQ sub‐scale of emotional eating and implicit measures of attitude, explicit attitude and behaviour measures concerning chocolate consumption. In both studies, high emotional eaters were more likely than low emotional eaters to eat in line with their implicit measures of attitudes. The relationship between implicit measures of attitudes and food intake varies as a function of emotional eating style. Copyright © 2010 John Wiley & Sons, Ltd.     

Interpersonal consequences of joint food consumption for connection and conflict

For centuries, the preparation and eating of a meal has brought people together, making food consumption an inherently social process. Yet the way in which people connect over food is changing. Rising health concerns, due in part to the increase in food allergies and obesity, have shifted attention away from the social aspects of food to food's nutritional aspects. Recognizing the social context in which food consumption takes place, this article reviews research highlighting the interpersonal consequences of joint food consumption. We first examine research on how sharing food connects people together, both via the type of food consumed (e.g., incidental food similarity) and the manner in which people serve and eat food (e.g., from shared vs. separate plates). We then turn to research that addresses the opposite side of the coin, discussing how the inability to share in a meal can be isolating, as well as how people navigate conflicting preferences when making food decisions with others. We conclude with a discussion of promising future directions for research on joint food consumption.     

情绪对饮食行为的影响

人类的饮食行为受到诸多因素的影响, 包括生理因素、心理因素及社会文化因素等, 其中情绪对饮食行为的影响日益受到研究者的重视, 这种影响一般表现为摄入量的多少和食物(热量)的选择。通过探讨不同情绪下临床和非临床个体食物摄入量的表现, 总结发现消极情绪导致个体暴饮暴食的可能更大。积极情绪影响下的饮食行为的研究结果则存在分歧: 生理角度解释为积极情绪能够促进个体的享乐机制, 导致进食行为增加; 而自我控制理论则认为积极情绪增加了个人资源以抵制美食诱惑。此外, 进一步探讨了情绪影响下饮食行为的神经生理机制。未来在饮食相关的临床研究和治疗上, 需要对情绪影响下的饮食行为有更深入的神经机制方面的探究。     

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.     

Are we aware of the external factors that influence our food intake?

OBJECTIVES: This research examines the extent to which people accurately report some of the external influences on their food intake. DESIGN: In two studies, specific factors (the presence and behavior of others) were manipulated in order to influence the amount of food that individuals consumed. MAIN OUTCOME MEASURES: The main outcomes of interest were participants' spontaneously generated explanations for their food intake (Study 1; n = 122), and their ratings of the importance of several potential determinants of food intake (Study 2; n = 75). RESULTS: In Study 1, there was high concordance between the amounts eaten by members of a dyad, but very few participants indicated that they were influenced by their partner's behavior; they instead identified hunger and taste as the primary determinants of intake. Study 2 showed that participants' intake was strongly influenced by the behavior of others, but people rated taste and hunger as much more important influences on their intake. CONCLUSIONS: If external environmental factors influence people's food intake without their awareness or acknowledgment, then maintaining a healthy diet can be a challenge, with long-term consequences for health and well-being.     

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.

     

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.     

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.     

Unit bias. A new heuristic that helps explain the effect of portion size on food intake

ABSTRACT— People seem to think that a unit of some entity (with certain constraints) is the appropriate and optimal amount. We refer to this heuristic as unit bias. We illustrate unit bias by demonstrating large effects of unit segmentation, a form of portion control, on food intake. Thus, people choose, and presumably eat, much greater weights of Tootsie Rolls and pretzels when offered a large as opposed to a small unit size (and given the option of taking as many units as they choose at no monetary cost). Additionally, they consume substantially more M&M's when the candies are offered with a large as opposed to a small spoon (again with no limits as to the number of spoonfuls to be taken). We propose that unit bias explains why small portion sizes are effective in controlling consumption; in some cases, people served small portions would simply eat additional portions if it were not for unit bias. We argue that unit bias is a general feature in human choice and discuss possible origins of this bias, including consumption norms.     

A method for the control of eating rate: A potential intervention in eating disorders

A method for the control of eating rate gave subjects feedback from a computer screen on how much and at what rate to eat during a meal. The method also allowed us to record the development of satiety during the meal. Linear eaters—that is, women selected for eating at an approximately constant rate—underate when challenged to eat at a lower rate and overate when challenged to eat at a higher rate, thereby modeling the eating behavior of patients with anorexia nervosa and binge eating disorder, respectively. In both cases, the women’s postmeal perception of satiety mimicked that of the respective patient group. The results provide support for the notion that linear eaters have the capacity to exhibit disordered eating.     

The pull of the past: when do habits persist despite conflict with motives?

To identify the factors that disrupt and maintain habit performance, two field experiments tested the conditions under which people eat out of habit, leading them to resist motivational influences. Habitual popcorn eaters at a cinema were minimally influenced by their hunger or how much they liked the food, and they ate equal amounts of stale and fresh popcorn. Yet, mechanisms of automaticity influenced habit performance: Participants ate out of habit, regardless of freshness, only when currently in the context associated with past performance (i.e., a cinema; Study 1) and only when eating in a way that allowed them to automatically execute the response cued by that context (i.e., eating with their dominant hand; Study 2). Across all conditions, participants with weaker cinema-popcorn-eating habits ate because of motivations such as liking for the popcorn. The findings reveal how habits resist conflicting motives and provide insight into promising mechanisms of habit change.     

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     

Perceived warmth and competence of others shape voluntary deceptive behaviour in a morally relevant setting

The temptation to deceive others compares to a moral dilemma: it involves a conflict between the temptation to obtain some benefit and the desire to conform to personal and social moral norms or avoid aversive social consequences. Thus, people might feel different levels of emotional and moral conflict depending on the target of the deception. Here we explored, in a morally relevant setting, how social judgements based on two fundamental dimensions of human social cognition – ‘warmth’ and ‘competence’ – impact on the decision to deceive others. Results revealed independent effects for warmth and competence. Specifically, while people are less inclined to deceive for self-gain those individuals they perceive as warm, they also tend to lie more to highly competent others. Furthermore, the perceived warmth and competence modulated the general tendency to reduce deceptive behaviour when there was a risk of disclosure compared to when the lying was anonymous, highlighting the importance of these judgements in social evaluation processes. Together, our results demonstrate that the emotional costs and personal moral standards that inhibit engagement in deceptive behaviour are not stable but rather malleable according to the target and the consequences of the deception.     

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.     

Burger or yogurt? Indulgent consumption in impression management contexts

We conducted three studies to investigate indulgent choice in settings with and without impression management by public–private manipulation with evaluation. Study 1 showed that the participants were less indulgent under public scrutiny due to the employment of impression management. Study 2 focused on the impression management context to test the moderate effect of self‐consciousness in two impression managed contexts. Study 3 focused on context without impression management to test the moderate effects of self‐awareness on choices. We found that depending on differences in primed personality, individuals tended to make choices other than those they favoured privately when anticipating that others might form impressions of them based on the decisions made. The findings of all three studies support our basic prediction that people are less indulgent under impression management and suggest that people tend to manage their impression by eating healthier (less indulgently) in public.     

奖赏敏感性在冲动性饮食行为中的作用

肥胖会导致癌症、心脏病、糖尿病等诸多健康问题,而冲动性饮食是肥胖的一个重要影响因素。厘清奖赏敏感性在冲动性饮食中的作用,有助于深入理解冲动性饮食行为。本文介绍了奖赏敏感性的概念、涉及的主要研究领域、生物学基础及测量;整理归纳出奖赏敏感性影响冲动性饮食的三种可能路径:通过注意力偏向影响对享乐性食品的感知、影响消费欲望及随后的自我控制;文章最后指出了基于奖赏敏感性对冲动性饮食进行拓展研究的可能方向。