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.     

Bulimics' responses to food cravings: is binge-eating a product of hunger or emotional state?

This study examined the roles of hunger, food craving and mood in the binge-eating episodes of bulimic patients, and identified the critical factors involved in the processes surrounding binge-eating episodes that follow cravings. This was a prospective study of the binge-eating behaviour of 15 women with bulimia nervosa. The participants used food intake diaries and Craving Records to self-monitor their nutritional behaviour, hunger levels and affective state. Cravings leading to a binge were associated with higher tension, lower mood and lower hunger than those cravings not leading to a binge. Levels of tension and hunger were the critical discriminating variables. The findings of the study support empirical evidence and models of emotional blocking in binge-eating behaviour and challenge the current cognitive starve-binge models of bulimia. The role of food cravings in the emotional blocking model is discussed in terms of a classically conditioned motivational state. Implications for treatment are addressed.     

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.     

The effect of hunger on water intake in rats

Although reciprocal inhibition between eating and drinking has been postulated, the commonly observed reduction of water intake by hungry rats may not be due to any direct inhibitory mechanism. In one experiment rats deprived of food for 24 hr. and then injected with 2 ml. of NaCl drank the same as rats that had received food ad lib. In the second experiment a stomach load of 10 ml. of water 3 hr. before the salt injection was designed to abolish any water deficit that might have occurred during food deprivation had there been inhibition of drinking by hunger. Here again rats deprived of food did not drink less than undeprived animals. In fact the hungry rats drank slightly but significantly more. This phenomenon may be related to the observation confirmed here that during food deprivation rats excrete about twice as much rather dilute urine as during ad lib food intake. This seems to indicate that though in general food deprived rats drink less than normal they actually drink more than they need. Schedule induced polydipsia also occurs during food deprivation and this too makes it unlikely that water-intake is actually inhibited during hunger.     

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.     

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.     

Mapping the tip of the tongue--deprivation, sensory sensitisation, and oral haptics

We investigated the impact of food deprivation on oral and manual haptic size perception of food and non-food objects. From relevant theories (need-proportional perception, motivated perception, frustrative nonreward, perceptual defence, and sensory sensitisation) at least four completely different competing predictions can be derived. Testing these predictions, we found across four experiments that participants estimated the length of both non-food and food objects to be larger when hungry than when satiated, which was true only for oral haptic perception, while manual haptic perception was not influenced by hunger state. Subjectively reported hunger correlated positively with estimated object size in oral, but not in manual, haptic perception. The impact of food deprivation on oral perception vanished after oral stimulations even for hungry individuals. These results favour a sensory sensitisation account maintaining that hunger itself does not alter oral perception but the accompanying lack of sensory stimulation of the oral mucosa. Both oral and manual haptic perception tended to underestimate actual object size. Finally, an enhancing effect of domain-target matching was found, ie food objects were perceived larger by oral than by manual haptics, while non-food objects were perceived larger by manual than by oral haptics.     

The influence of demand characteristics and expectancies in the measurement of salivary response

The sensitivity of salivary response measures to demand and expectancies was studied. One hundred thirty-one college students were tested for increases or decreases in salivation under one of three conditions: (a) when told to imagine the taste of another food more or less palatable than a target food; (b) when given a placebo pill that, they were told, would alter their salivation; and (c) when given direct instructions to alter their salivation. The type of instructions subjects received altered their salivation response. Specifically, subjects told to increase salivation had higher levels than those told to decrease salivation. These results suggest that salivation measures, which have been viewed by some as refractory to demand and related effects, can be controlled. Additional results of the study call for further validation of salivation as a measure of hunger and perceived food palatability.     

Predictors of disinhibited eating in children with and without overweight

OBJECTIVE: This study examined how 7-13-year-old children with and without overweight respond to free access to snack food in the absence of hunger and whether this eating behaviour could be predicted by parental feeding strategies and child's characteristics. METHODS: A total of 52 children (26 normal weight and 26 overweight children) were exposed to snack food after consuming a typical meal. Parental feeding practices and child's variables were assessed via self-report. RESULTS: Two-third of the sample ate of the presented snacks and consumed an average of 68 g. Overweight boys consumed twice as much than the normal weight boys. Parental feeding strategies did not contribute to the prediction of this eating behaviour. Regardless of the children's weight status, the child's eating style strongly predicted snack intake. CONCLUSIONS: This study provides evidence that overweight boys show difficulties in regulating their eating behaviour. Inconsistent with previous work, no evidence for parental contribution of snack intake was found. The present findings suggest that in older children especially children's own eating style account for the variance in snack eating behaviour.     

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.     

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.     

Internal and external factors modulate food-calling in domestic hens

Two series of experiments investigated factors affecting utterance of food calls in the domestic hen, Gallus domesticus. The first series of experiments tested the effect of food preference and the hen’s internal state on the utterance of food calls. Different food types were presented first singly and then in a choice test to 20 hens, first when hens were laying, and then when they were maternal. The second series of experiments tested the effect of hunger level on the utterance of food calls in laying hens, and maternal hens with or without chicks. These two series of experiments showed that laying hens and maternal hens showed a similar marked preference for certain types of food, but laying hens very rarely emitted food calls, in contrast to maternal hens. This shows the effect of the bird’s psychophysiological state on her tendency to emit food calls. The more a maternal hen preferred a food type, the more food calls she emitted. This was observed from the beginning of a test in single-food tests as well as in choice tests. Hunger level positively affected food-call production under certain feeding conditions in maternal hens, but not in laying hens. When maternal hens were tested in the absence of their chicks, utterance of food calls was more sustained than in the presence of chicks. Received: 14 May 1998 / Accepted after revision: 11 October 1998     

生命早期环境不可预测性对过度进食的影响:基于生命史理论

在生命史理论的视角下, 本研究通过两个研究揭示了生命早期环境不可预测性对过度进食的影响及其作用机制。研究1招募处于生命早期阶段的91名初中生(年龄12~14岁), 采用饱食进食(Eating in the absence of hunger, EAH)范式, 结果发现生命早期环境不可预测性能够显著正向预测个体饱食状态下的高热量食物选择(即过度进食); 研究2招募新冠病毒疾病(COVID-19)暴发背景下301名武汉市居民(高死亡威胁组)和179名其他省市居民(控制组) (年龄18~60岁)为被试, 通过问卷法回溯性地测量生命早期环境不可预测性并探究其影响当前过度进食的机制, 结果发现生命早期环境不可预测性通过生命史策略的中介作用间接影响过度进食。同时, 死亡威胁(新冠病毒疫情)扩大了环境不可预测性通过生命史策略间接影响过度进食的效应, 而社会支持则能缓冲这一效应。研究结果为COVID-19背景下和灾后居民的健康进食干预提供了依据。     

Rats learn to eat more to avoid hunger

Several recent experiments have provided evidence that the ingestion of a distinctive food by rats can be a learnt instrumental act as well as an associatively conditioned reaction. In the previous work, maintenance food was withheld for shorter and longer durations on different days following access to the training food. Extra eating before the longer fast was interpreted as avoidance of hunger. This interpretation was based on the evidence showing that extra eating as a result of classical conditioning comes from pairing food stimuli with the presence of little or no hunger because of repletion with energy nutrients. The theory that the extra eating arose from a response-depletion contingency was tested in the present experiment by training rats on only a long fast or only a short fast. Greater increase in intake was seen before the longer fast. The results also replicated previously seen cycles of increase, decrease, and renewed increase in putative deficit-avoidant eating over about three trials, indicating that the extra eating reduces the response-reinforcing hunger and that the consequent part-extinction restores reinforcement. The shape of the learning curve was consistent with these cycles occurring from the start of training, further supporting the view that the increase in food intake before a long delay in refeeding is hunger-reinforced instrumental behaviour.     

友谊质量与青少年直觉进食：链式中介模型及性别差异

基于积极心理学, 采用友谊质量量表、自我怜悯量表、身体欣赏量表和直觉进食量表, 对2438名初中生进行调查, 并运用结构方程模型探讨友谊质量与青少年直觉进食的关系、作用机制及其性别差异。结果表明：(1)友谊质量与直觉进食呈显著正相关; (2)自我怜悯和积极身体意象在友谊质量与直觉进食间起中介作用, 且该中介作用包含三条路径：自我怜悯的单独中介作用、积极身体意象的单独中介作用以及自我怜悯-积极身体意象的链式中介作用; (3)中介效应性别差异仅出现在友谊质量与直觉进食(分维度)的关系中, 即“无条件地允许进食”和“进食不受情绪影响”两个维度。研究结果为促进青少年形成积极身体意象、健康饮食行为提供了参考建议和干预指导。     

Predicting Hunger: The Effects of Appetite and Delay on Choice

Preferences often fluctuate as a result of transient changes in hunger and other visceral states. When current decisions have delayed consequences, the preferences that should be relevant are those that will prevail when the consequences occur. However, consistent with the notion of an intrapersonal empathy gap (Loewenstein, 1996) we find that an individual's current state of appetite has a significant effect on choices that apply to the future. Participants in our study made advance choices between healthy and unhealthy snacks (i.e., fruit and junk food) that they would receive in 1 week when they were either hungry (late in the afternoon) or satisfied (immediately after lunch). In 1 week, at the appointed time, they made an immediate choice, an opportunity to change their advance choice. Our main predictions were strongly confirmed. First, advance choices were influenced by current hunger as well as future hunger: hungry participants chose more unhealthy snacks than did satisfied ones. Second, participants were dynamically inconsistent: they chose far more unhealthy snacks for immediate choice than for advance choice. An additional hypothesis related to gender differences was also confirmed.     

Visceral drives in retrospect: explanations about the inaccessible past

The present research demonstrates that the extent to which people appreciate the influence past visceral states have had on behavior (e.g., the influence hunger has had on food choice) depends largely on their current visceral state. Specifically, we found that when people were in a hot state (e.g., fatigued), they attributed behavior primarily to visceral influences, whereas when people were in a cold state (e.g., nonfatigued), they underestimated the influence of visceral drives and instead attributed behavior primarily to other, nonvisceral factors. This hot-cold empathy gap was observed when people made attributions about the past behavior of another person or themselves, and proved difficult to overcome, as participants could not correct for the biasing influence of their current visceral state when instructed to do so. These different attribution patterns also had consequences for people's satisfaction with their performance. Those who attributed their poor performance to visceral factors were more satisfied than those who made dispositional attributions.     

A bioinspired model of short-term satiety of hunger influenced by food properties in virtual creatures

The behavior of the human is continually changed as a consequence of various drives which human is predisposed also of your survival instinct. Among the basic drives of the human, there are the physiological needs and is precisely the hunger that motivates the food intake to get the energy that the body requires via food. The regulation of hunger allows to stop the food intake by means of the homeostatic and hedonic control which are influenced by the food properties. The process that consists of ending the food intake is known as short-term satiety and is important because it limits the amount of food intake; Otherwise, an over-consumed affect the organism functioning negatively. In this paper, we propose a conceptual model for the generation of short-term satiety behaviors based on neuroscientific evidence for virtual creatures. The conceptual model proposed is implemented in a distributed system-a virtual creature endowed with this implementation is placed in a virtual environment to analyze its behavior. The analysis shows how the virtual creature modifies its hunger level (behavior) based on food’s properties. The results show the execution of the process when the creature interacts with the environment.     

Disorders of Eating in the Elderly

The most common eating disorder in the elderly in both community and hospital settings is food refusal. This may lead to weight loss and malnutrition with all the adverse consequences on independence and function. The management of disorders of eating in the elderly is a diagnostic and therapeutic challenge, requiring the combined skills of the medical and nursing staff. The causes are often multifactorial and require careful and repeated assessment of the patient's social, psychological, and medical history. Approach to treatment involves these factors, as well as ethical and cultural considerations. Eating is the most basic biological drive for survival in nature. In human societies there are additional cultural and social aspects that may override this instinct, as in the case of hunger strikes for political motives. In the elderly, food is one of the major sources of possible pleasure and it is the challenge for health providers to try and give this enjoyment to their patients for as long as possible.     

Effects of previous delay of reward,generalized effort,and deprivation on impulsiveness

Two experiments investigated the effects of learning and motivational variables upon rats' degree of impulsiveness (choice of a small, immediate reward versus a large, delayed reward). In Experiment 1, food was presented in one of four ways for 24 sessions: fixed-ratio lever pressing requirement, continuous-reinforcement lever-pressing requirement, long intervals between free food presentations, or short intervals between free food presentations. Exposure to the long intervals produced less subsequent impulsiveness in 48 choice trials than did the short intervals, there being no effect of the instrumental requirement. In Experiment 2, there were 48 choice trials in which two hunger levels were combined factorially with two delays of reward for the self-control alternative. Hunger level did not affect implusiveness when there was a short delay, but high hunger increased the impulsiveness when there was a long delay. These results indicate that impulsiveness is affected by prior learning and current motivation. Implications for Baum, Rachlin, and Green's matching formula and for frustration theory are discussed.