Guilty pleasures II: restrained eaters' implicit preferences for high, moderate and low-caloric food

In a previous study, restrained eaters showed stronger implicit preferences for high-caloric food compared to unrestrained eaters. Caloric density and palatability are however almost always intertwined, and it was never tested whether this high-calorie food preference of restrained eaters follows from the energy density or the palatability of high-calorie foods. Here, it was examined whether restrained eaters may hold stronger implicit preferences than unrestrained eaters for palatable food in general, irrespective of caloric density. Participants were randomly assigned to one of three conditions: Using two unipolar SCIATs positive and negative implicit associations were measured with palatable food of either high, moderate, or low caloric density. Results showed a strong effect of dietary restraint on implicit food preferences independently of caloric density, indicating stronger implicit preferences for all types of palatable food with increased dietary restraint. With respect to negative implicit associations, participants showed stronger negative implicit associations with high-calorie food than with moderate-calorie or low-calorie food, regardless of dietary restraint. Thus, restrained eaters show enhanced implicit preferences, not only for high caloric food, but for palatable food in general compared to unrestrained eaters.     

Attentional biases to foods: The effects of caloric content and cognitive restraint

The goal of the present study was to determine whether female restrained and unrestrained eaters demonstrated differential levels of attentional bias to high calorie foods when they were presented as distractors in a flanker task. This task consisted of four blocks of 68 trials in which three food pictures were briefly presented simultaneously on a computer screen. On each trial a high or low calorie target food was presented in the center of a pair of high or low calorie food flanker pictures and participants' reaction times to answer a basic question about whether they would consume the target food for breakfast were recorded. In Experiment 1, in which all participants were fed a snack prior to engaging in the flanker task, there was no evidence that restrained (n=29) or unrestrained (n=37) eaters had an attentional bias. However, in Experiment 2, when participants completed the flanker task while hungry, restrained eaters (n=27) experienced response conflict only when low calorie targets were flanked by high calorie distractors, whereas unrestrained eaters (n=46) were distracted by high calorie flankers regardless of the caloric content of the target cue. The results from this implicit task indicate that flankers interfere with hungry participants' responses to varying degrees depending on their cognitive restraint. Whether attentional bias to food cues subsequently affects food choices and eating behavior is a topic for further investigation.     

Perceived caloric content of a preload and disinhibition among restrained eaters

The present study examined the effects of the perceived caloric content of a preload on the eating behaviour of restrained and unrestrained eaters. Participants were randomly assigned to one of the three experimental conditions in which they ingested an isocaloric milkshake preload presented as either high or low in calories, or no preload. Subsequent ad lib food consumption was measured. Both the high-calorie and the low-calorie milkshakes elicited disinhibited eating among restrained eaters, with a non-significant difference between the two preload conditions in terms of food consumption. Participants overall reported that consumption of the ostensibly high-calorie milkshake was more anxiety provoking for them than was the low-calorie milkshake. However, anxiety did not predict intake in the preload conditions. These results demonstrate that even low-calorie "forbidden" foods can elicit disinhibited eating among restrained eaters.     

Development and implementation of a visual card-sorting technique for assessing food and activity preferences and patterns in African American girls

OBJECTIVE: Card-sorting tasks for assessing food and activity preferences and patterns among African American girls were developed. Associations among food preference and intake frequency, activity preference and frequency, and body mass index were examined. DESIGN: Participants completed newly developed card-sorting tasks assessing food and activity preferences and patterns. Height and weight were measured. SUBJECTS/SETTING: Ninety-six 8- to 10-year-old African American girls from schools and community centers in Minneapolis-St. Paul. MAIN OUTCOME MEASURES: Preference and frequency data for 64 foods/beverages and 34 activities. STATISTICAL ANALYSES: Frequencies for food and activity preference and frequency categories were computed. Pearson correlations among food and activity preference, frequency, and body mass index were computed. RESULTS: High-sugar (eg, fruit drinks, soda) and/or high-fat (eg, ice cream, cookies) foods were among the most popular and frequently consumed. Ninety-six percent of girls liked fruit drinks, with 35% consuming them "almost every day." Less-structured activities such as biking, games, jump rope, and dance were most popular. Biking was preferred by 85% of girls, with 48% biking "almost every day." Food preference and frequency categories were moderately correlated (r=0.30 to 0.58), as were activity preference and frequency (r=0.37 to 0.49). APPLICATIONS: The card-sorting tasks are useful tools for assessing food and activity preferences and patterns in girls. Obesity prevention programs for African American girls should include preferred activities such as dance, jump rope, and active play. Programs may also benefit from a focus on replacing high fat/high sugar snacks and sweetened beverages with low-fat, lower-calorie snacks and beverages (eg, fruit, vegetables, water).     

A new reference method for the validation of the nutrient profiling schemes using dietary surveys

Nutrient profiles of foods are increasingly used as the scientific basis of nutritional labeling, health claims, or nutritional education. Nutrient profiling schemes are based on sets of rules, scores, or thresholds applied to the nutritional composition of foods. However, there is a lack of scientific validation of nutritional profiling schemes. To develop a reference method using existing dietary surveys, to define a set of indicator foods that are positively or negatively associated with a "healthy diet." Such indicator foods can be used both for establishing relevant nutrient profiles and for the validation of existing or future nutrient profiling schemes. The proposed validation method is based on food and nutrient intakes of adults participating in national dietary surveys in five EU countries: Belgium (n = 2,507), Denmark (n = 3,151), France (n = 1,474), Ireland (n = 1,379), and Italy (n = 1,513). The characterization of indicator foods is divided in two steps. First, "healthy diets" of individuals are identified in the five national dietary surveys by comparison to the Eurodiet reference intakes. Second, indicator foods associated positively or negatively to the "healthy diets" are determined. With a P-value of 10(-3) for the test of comparison of food intakes between the "most healthy eaters" and the "less healthy eaters," it was possible to identify 294 indicator foods out of 1,669 foods tested in the five countries. In all the countries except Italy, there were more indicator foods positively associated than indicator foods negatively associated with the "healthy diet." The food categories of these indicator foods were in good agreement with Food Based Dietary Guidelines like the USDA dietary guideline for Americans. A new reference method for the validation of profiling schemes was developed based on dietary intake data from using dietary surveys in five European countries. Only a minority of foods consumed in these dietary surveys could be used as indicator foods of healthy or unhealthy diets in order to subsequently test nutritional profiling schemes. Further work is needed to build a list of indicator foods that could be considered as a "gold standard."     

The nutrient and food intakes of 16–17 year old female dieters in the UK

A group of female teenage dieters was isolated from a larger national dietary survey of teenagers at 16–17 years of age. The dieting group included girls who both claimed to be dieting and who had energy intakes which were considered appropriate for weight loss, based on calculated reported energy intake to estimated basal metabolic rate cut-off points. The nutrient intakes and food choices of dieters (n= 204) were compared with a similar sample of non-dieters (n= 226) from the same cohort group. The mean reported energy intake of the dieters was 1604 kcals/day compared to 2460 kcals/day amongst non-dieters. The intakes of all the macronutrients in g/day were considerably lower amongst dieters, allowing for differences in region and social class, but when expressed as a percentage of energy intake, dieters had significantly lower intakes of fat and higher intakes of protein and intrinsic sugars, milk sugars and starch. No differences were seen in the percentage of energy provided by non-milk extrinsic sugars between the two groups. The intake of all micronutrients was substantially lower amongst dieters, allowing for regional and social class differences, and more than twice as many dieters as non-dieters failed to achieve the reference nutrient intake (RNI) for retinol equivalents, thiamin, riboflavin, folates, vitamin B12, vitamin B₆, zinc, copper and selenium. Reported food intake data for the two groups suggest that dieters consumed smaller quantities of most foods, although intakes of items associated with dieting such as low calorie soft drinks, low fat spread, skimmed milk, cottage cheese, yoghurt, salad vegetables, fruit and fruit juice were consumed in equal or greater amounts by dieters. Teenage dieters should be encouraged to include more nutrient-dense foods in their diets such as fortified breakfast cereals and low fat dairy products in order to obtain sufficient micronutrients from a lower calorie intake.     

Individual differences in food perceptions and calorie estimation: an examination of dieting status, weight, and gender

People frequently place foods into "health" or "diet" categories. This study examined whether (1) evaluations of "healthiness/unhealthiness" influence "caloric" estimation accuracy, (2) people evaluate foods for "healthiness/unhealthiness" or "weight gain/loss" differently, and (3) food evaluations differ by gender, diet status, and weight. Also, undergraduate dieters attempting to lose weight on their own were compared to obese weight loss program participants. Undergraduate students (N=101) rated eight "healthy" and "unhealthy" foods on perceived "healthiness/unhealthiness," "weight loss/gain capacity" and "caloric" content. Open-ended questions inquiring why a food was "healthy/unhealthy" or would "contribute to weight gain/loss" were coded into independent food categories (e.g., high fat). Results indicate that calories were systematically underestimated in healthy/weight loss foods, while they were systematically overestimated in unhealthy/weight gain foods. Dieters were more accurate at estimating "calories" of healthy foods and more attentive to the foods' fat, "calorie", and sugar content than non-dieters. Overweight participants commented more on fat and sugar content than normal weight participants. Undergraduate dieters used fewer categories for evaluating foods than weight loss program participants. Individual difference characteristics, such as diet-status, weight, and gender, influence people's perceptions of foods' healthiness or capacity to influence weight, and in some instances systematically bias their estimates of the caloric content of foods.     

Cognitive and emotional responses to food

The present study evaluated the cognitive and emotional responses to eating a high-calorie food. Restrained and unrestrained, normal-weight women were given either a high-calorie food or a low-calorie food and completed ratings of hunger and questionnaires concerning their emotional and cognitive states before and after eating. Finally, they were given a taste test, then debriefed, and interviewed about their experience of the study. The interview data and the psychometric results indicated that the restrained eaters experienced increased feelings of rebelliousness and defiance after both eating situations, with this increase being particularly pronounced after the high-calorie food. The unrestrained eaters did not show an increase in rebelliousness nor any differentiation between the high- and low-calorie foods. The restrained eaters also showed a decrease in anxiety after the high-calorie food. The results are analyzed in terms of recent theories of restrained eating and their implications for pathological eating regulation are discussed.     

Consumers may not use or understand calorie labeling in restaurants

This study was an investigation of the possible utility of calorie labeling legislation in restaurants in community (n=649) and college student (n=316) samples. Only 48% to 66% of participants presently looked at food labels, and 64% to 73% were able to report accurate knowledge of daily caloric needs. Furthermore, 44% to 57% reported that they were not likely to use food label information in restaurants if it were available. Therefore, public education campaigns focused on calorie requirements may need to precede restaurant labeling, and perhaps other possibilities in labeling formats should be considered (eg, defining foods as "low," "moderate," and "high" calorie).     

High-calorie food-cues impair working memory performance in high and low food cravers

The experience of food craving can lead to cognitive impairments. Experimentally induced chocolate craving exhausts cognitive resources and, therefore, impacts working memory, particularly in trait chocolate cravers. In the current study, we investigated the effects of exposure to food-cues on working memory task performance in a group with frequent and intense (high cravers, n=28) and less pronounced food cravings (low cravers, n=28). Participants performed an n-back task that contained either pictures of high-calorie sweets, high-calorie savory foods, or neutral objects. Current subjective food craving was assessed before and after the task. All participants showed slower reaction times and made more omission errors in response to food-cues, particularly savory foods. There were no differences in task performance between groups. State cravings did not differ between groups before the task, but increased more in high cravers compared to low cravers during the task. Results support findings about food cravings impairing visuo-spatial working memory performance independent of trait cravings. They further show that this influence is not restricted to chocolate, but also applies to high-calorie savory foods. Limiting working memory capacity may be especially crucial in persons who are more prone to high-calorie food-cues and experience such cravings habitually.     

Restrained eating is related to accelerated reaction to high caloric foods and cardiac autonomic dysregulation

Cognitive bias to food-cues and cardiac autonomic dysregulation have both been related to disordered eating behavior in previous research. The present study investigated two possible measures of self-regulatory ability in restrained eaters: resistance to distractor interference and vagal-cardiac control. Young women (N=47) performed a flanker task involving high caloric food-cues or neutral pictures. Vagal-cardiac activity was calculated from baseline heart rate recordings at rest. Restrained eaters did not differ from unrestrained eaters in resistance to distractor interference. However, restrained eaters showed shorter reaction times to high-calorie food-cues as compared to neutral pictures than unrestrained eaters. This attentional bias was further related to low dieting success. Moreover, restrained eating was associated with low parasympathetic activation and sympathovagal imbalance, independent of current body mass. Both attentional bias and cardiac autonomic dysregulation were related to self-reported weight fluctuations. Results are discussed in terms of possible adverse consequences of weight cycling in young women and low self-regulatory ability in restrained eaters.     

Nutrient intakes in relation to style of breakfast and taste preferences.

Style of breakfast (western- or Japanese-style) and taste preferences were associated with various diseases in some epidemiological studies in Japan. To evaluate what are measured by asking these dietary behaviors, we administered semiquantitative food frequency questionnaire (SFFQ) and asked style of breakfast and taste preferences to a subsample of residents in Takayama City, Gifu, Japan. Style of breakfast and total diet were studied in a random sample of 346 residents. There were no statistically significant differences in the nutrient intakes estimated from SFFQ between those with western- and Japanese-style of breakfast except for crude fiber. Taste preferences were asked to 555 men and 1,130 women who attended a health check-up program in the community. Salt intakes were slightly higher (< 3%) in those who had a favor for salty food than the others in both sexes. Fat or carbohydrate intake was similar between those stratified by preference for greasy or sweet foods. The data suggest that western-style of breakfast is not associated with western diet, in general, i.e., high-calorie and high-fat diet. Intakes of salt, fat, or carbohydrate appear to be unrelated to preferences for salty, greasy or sweet foods, respectively.     

The tempting effect of forbidden foods. High calorie content evokes conflicting implicit and explicit evaluations in restrained eaters

In this study, restrained and unrestrained eaters' immediate evaluations of high calorie content and low calorie content were measured, both when being deprived of food and when satiated. As an indirect measure, the Extrinsic Affective Simon Task (EAST) [De Houwer, J. (2003). The Extrinsic Affective Simon Task. Experimental Psychology, 50, 77-85.] was used. Explicit attitudes towards high calorie content and low calorie content were also assessed. Food deprivation was found to boost the value of food for all subjects on an impulsive level of information processing. More importantly, it was also found that restrained eaters exhibit a dissociative pattern of positive implicit and negative explicit attitudes towards high calorie content, but not towards low calorie content. Furthermore, restrained eaters evaluated high calorie content more negative than unrestrained eaters on an explicit level, but more positive on an implicit level. Results from this study are twofold. First, they suggest that conflicting evaluative reactions from two systems of information processing may play a central role in the restrained eater's dilemma. Second, individual differences between restrained and unrestrained eaters' attitudes towards high calorie content should further be investigated.     

Time of day influences food acceptability

To determine whether a food's acceptability changes with time of day and degree to which a food is appropriate for a given mealtime, preferences were obtained both in the morning and the afternoon for a set of foods which included items appropriate "for breakfast", "for dinner", or for either mealtime. A second purpose of the study was to determine whether such cultural rules regarding food appropriateness had been acquired by preschool children and whether the pattern of shifting acceptability with time of day predicted for adult subjects would also appear in the preference data of the children. Participants included 25 adults and 30 three- and four-year-old children. All subjects were seen twice, once in the morning and once in the late afternoon for two identical sessions. Half of the subjects in each age group were seen first in the morning, half were seen first in the afternoon. In these sessions food preferences for the set of foods varying in mealtime appropriateness were assessed and the foods were categorized as "for breakfast" of "for dinner". The preference data of both the adults and the children showed significant preference shifts with time of day, with breakfast items more preferred in the morning than the afternoon and dinner items more preferred in the morning than the afternoon. These shifts were larger for adults than for children but not significantly so.     

Behavioral and biological correlates of dietary restraint in normal life

Based on laboratory results, restrained eating has been linked to the development of binge eating and eating disorder syndromes such as bulimia nervosa. This study was designed to extend the scope of investigation of the concept of restrained eating beyond the laboratory. Eating behavior and biochemical indices of nutritional state were investigated in 60 young women, who were divided in restrained and unrestrained eaters by questionnaire. Seven-day records of food intake showed that the high-restraint group ate around 400 kcal a day fewer than the low-restraint group. Group differences in actual macronutrient intake and long-term food preferences pointed to a qualitatively altered eating pattern in restrained eaters. Actual protein portion was higher in restrained eaters. They tried to avoid calorie dense food items of high carbohydrate and fat content. Instead, they preferred food regarded as low-caloric and healthy. Plasma levels of triiodothyronine and glucose, which could be taken as indices of long-term adaptation to starvation, were not decreased in the high-restraint group. However, significantly higher levels of triglycerides in restrained eaters may reflect a biological state due to short-term starvation. The results indicate that the concept of dietary restraint predicts eating behavior not only under experimental conditions, but also in normal life. As a consequence of altered eating patterns, psychological and physiological deprivation can be hypothesized in restrained eaters, making them prone to the occurrence of overeating.     

Enhanced behavioral inhibition in restrained eaters

Lack of inhibitory control has been found to play a decisive role in disordered eating behavior. Behavioral and self-report measures show impulsive tendencies to even occur in non-clinical samples, e.g. restrained eaters. In restrained eaters, these traits interact with high reactivity to food-related cues leading to overeating. The aim of the present study was to investigate if restrained eaters would show this behavioral disinhibition specifically in response to food cues. Participants performed a Go/No-Go-task with stimuli encircled by pictures of high caloric foods or neutral objects. In contrast to our hypotheses, restrained eaters made less commission errors than unrestrained eaters independent of the picture type. Restrained eaters had higher reaction time as compared to unrestrained eaters solely when confronted with food pictures, indicating an attentional bias toward these stimuli. We interpret our results such that the lack of inhibitory control in restrained eaters is situation specific rather than general. We further speculate that exposure to food cues might have increased their behavioral inhibition as in real life situation when they succeed in maintaining their goal of restrained food intake.     

Dietary restraint and addictive behaviors: the generalizability of Tiffany's cue reactivity model

Two studies are presented, which examine cue reactivity in dieting. METHODS: Experiment 1 investigated whether the presence of a preferred food affected dieters' performance on measures of attention, reaction time, and motor speed. The manipulation did not affect the performance. Experiment 2 investigated the performance of dieters (N = 19), highly restrained non-dieters (N = 18) and low-to-medium restrained eaters (N = 34) on two simple reaction time tasks. Subjects were either required to imagine their favorite food or to imagine their favorite holiday while completing a reaction time task. RESULTS: In the food condition, both dieters and restrained nondieters displayed significantly slower reaction times during the first three of five blocks of the task than the low-to-medium restrained eaters. CONCLUSIONS: The results are discussed in terms of Tiffany's (Psychological Review 97:147-168, 1990) model of cue reactivity in that different abstinent states produce comparable effects upon performance.     

Both food preferences and food frequency scores predict fat intakes of women with breast cancer

OBJECTIVE: To determine whether self-reported frequencies of food use were linked to self-reported preferences for the same foods. The hypothesis was that both food frequencies and food preferences can predict nutrient intakes. RESPONDENTS: Participants were adult women patients (n = 339), recruited through the University of Michigan Breast Care Center. The sample included both persons with breast cancer and persons who were cancer-free. DESIGN: All women completed a 98-item food frequency questionnaire and rated preferences for many of the same foods using a 9-point category scale. Percent energy from fat and saturated fat, and intakes of dietary fiber and vitamin C were estimated from analyses of 4-day food records. STATISTICAL ANALYSES: Pearson correlations coefficients were used for data analysis. RESULTS: Dislike was a strong predictor of nonuse. In contrast, the more preferred foods were also reported as more frequently consumed. Significant correlations between preference and frequency scores were obtained for virtually all item pairs. Median Pearson correlation coefficient was 0.30 (range 0.04 to 0.56). Correlations improved when foods were aggregated into the chief dietary sources of fat, saturated fat, and vitamin C. Food frequencies and food preferences showed the same strength of association with percent energy from fat and saturated fat (r = 0.20 to 0.25). Food frequencies showed a stronger association with vitamin C intakes than did preferences for vegetables and fruit. APPLICATIONS: Food preferences may provide a potential alternative to the food frequency approach.     

The development of childhood dietary preferences and their implications for later adult health

The food fed to infants and young children not only determines their health in childhood but also predicts the foods that they eat in later life. Because adult dietary preferences are partially formed in childhood, the childhood diet inevitably contributes to the long‐term health of the individual. We are all aware of preferences that have endured since childhood, and that our dietary habits only change if we have reason to adapt them, perhaps for a healthier lifestyle. Adopting a healthy diet in adulthood is likely to be considerably easier if we have developed healthy food preferences during our childhood. Current information shows that toddlers are fed diets high in fat, sugar and salt and that mothers are confused about what toddlers should be eating. A healthy diet for toddlers combines foods from all the five food groups. This combination involves mixing high‐calorie and low‐calorie foods. Healthy food options should be introduced from weaning, and offered repeatedly through the infant and toddler years. Furthermore, the whole family should model a healthy eating lifestyle in order to foster the acceptance of foods that constitute a well‐balanced diet.     

Pre-exposure to diet-congruent food reduces energy intake in restrained dieting women

Dietary restriction often fails in the face of tempting and palatable foods; however there is evidence that exposure to diet-congruent cues, such as foods associated with ‘slimming’ may facilitate control over food intake. The present study examined the effect of exposure to a diet-congruent food on subsequent energy intake in active dieters. Using a within-subjects design, restrained eaters who were currently on a diet (n = 13) and unrestrained non-dieters (n = 21) were exposed to a tempting food cue (chocolate) and a diet-congruent food cue (fruit orange) on two separate testing sessions, and subsequent snack intake was measured. Unrestrained non-dieters consumed similar amounts of snack food across conditions, whilst restrained dieters consumed 60% less chocolate (kcal) after exposure to the diet cue compared to the tempting cue. Exposure to a diet-congruent food cues may help dieters control energy intake when tempted by palatable food.