ENVIRONMENTAL FACTORS THAT INCREASE THE FOOD INTAKE AND CONSUMPTION VOLUME OF UNKNOWING CONSUMERS

Package size, plate shape, lighting, socializing, and variety are only a few of the environmental factors that can influence the consumption volume of food far more than most people realize. Although such environmental factors appear unrelated, they generally influence consumption volume by inhibiting consumption monitoring and by suggesting alternative consumption norms. For researchers, this review suggests that redirecting the focus of investigations to the psychological mechanisms behind consumption will raise the profile and impact of research. For health professionals, this review underscores how small structural changes in personal environments can reduce the unknowing overconsumption of food.

Bottomless bowls: why visual cues of portion size may influence intake

OBJECTIVE

Using self-refilling soup bowls, this study examined whether visual cues related to portion size can influence intake volume without altering either estimated intake or satiation.

RESEARCH METHODS AND PROCEDURES

Fifty-four participants (BMI, 17.3 to 36.0 kg/m2; 18 to 46 years of age) were recruited to participate in a study involving soup. The experiment was a between-subject design with two visibility levels: 1) an accurate visual cue of a food portion (normal bowl) vs. 2) a biased visual cue (self-refilling bowl). The soup apparatus was housed in a modified restaurant-style table in which two of four bowls slowly and imperceptibly refilled as their contents were consumed. Outcomes included intake volume, intake estimation, consumption monitoring, and satiety.

RESULTS

Participants who were unknowingly eating from self-refilling bowls ate more soup [14.7+/-8.4 vs. 8.5+/-6.1 oz; F(1,52)=8.99; p<0.01] than those eating from normal soup bowls. However, despite consuming 73% more, they did not believe they had consumed more, nor did they perceive themselves as more sated than those eating from normal bowls. This was unaffected by BMI.

DISCUSSION

These findings are consistent with the notion that the amount of food on a plate or bowl increases intake because it influences consumption norms and expectations and it lessens one's reliance on self-monitoring. It seems that people use their eyes to count calories and not their stomachs. The importance of having salient, accurate visual cues can play an important role in the prevention of unintentional overeating.

Exploring comfort food preferences across age and gender

Building on findings related to physiological and psychological motivations of food preference, this research develops a framework to examine preferences toward comfort foods. Study 1 used a North American survey of 411 people to determine favored comfort foods, and Study 2 quantified the preferences for these foods across gender and across age groups using a stratified sample of 1005 additional people. Consistent with hypotheses, the findings showed different comfort food preferences across gender and across age. Males preferred warm, hearty, meal-related comfort foods (such as steak, casseroles, and soup), while females instead preferred comfort foods that were more snack related (such as chocolate and ice cream). In addition, younger people preferred more snack-related comfort foods compared to those over 55 years of age. Associations with guilty feelings underscored how these different preferences between males and females may extend to areas of application.

Evaluating Parents and Adult Caregivers as “Agents of Change” for Treating Obese Children: Evidence for Parent Behavior Change Strategies and Research Gaps

This scientific statement addresses parents and adult caregivers (PACs) as “agents of change” for obese children, evaluating the strength of evidence that particular parenting strategies can leverage behavior change and reduce positive energy balance in obese youth. The statement has 3 specific aims. The first is to review core behavior change strategies for PACs as used in family-based treatment programs and to provide a resource list. The second is to evaluate the strength of evidence that greater parental “involvement” in treatment is associated with better reductions in child overweight. The third is to identify research gaps and new opportunities for the field. This review yielded limited and inconsistent evidence from randomized controlled clinical trials that greater PAC involvement necessarily is associated with better child outcomes. For example, only 17% of the intervention studies reported differential improvements in child overweight as a function of parental involvement in treatment. On the other hand, greater parental adherence with core behavior change strategies predicted better child weight outcomes after 2 and 5 years in some studies. Thus, the literature lacks conclusive evidence that one particular parenting strategy or approach causally is superior to others in which children have a greater focus in treatment. A number of research gaps were identified, including the assessment of refined parenting phenotypes, cultural tailoring of interventions, examination of family relationships, and incorporation of new technologies. A conceptual model is proposed to stimulate research identifying the determinants of PAC feeding and physical activity parenting practices, the results of which may inform new treatments. The statement addresses the need for innovative research to advance the scope and potency of PAC treatments for childhood obesity.

Does food marketing need to make us fat? A review and solutions

Food marketing is often singled out as the leading cause of the obesity epidemic. The present review examines current food marketing practices to determine how exactly they may be influencing food intake, and how food marketers could meet their business objectives while helping people eat healthier. Particular attention is paid to the insights provided by recently published studies in the areas of marketing and consumer research, and those insights are integrated with findings from studies in nutrition and related disciplines. The review begins with an examination of the multiple ways in which 1) food pricing strategies and 2) marketing communication (including branding and food claims) bias food consumption. It then describes the effects of newer and less conspicuous marketing actions, focusing on 3) packaging (including the effects of package design and package-based claims) and 4) the eating environment (including the availability, salience, and convenience of food). Throughout, this review underscores the promising opportunities that food manufacturers and retailers have to make profitable "win-win" adjustments to help consumers eat better.

Bad popcorn in big buckets: portion size can influence intake as much as taste

OBJECTIVE

It is often believed that people overeat the foods they like. We investigated whether environmental cues such as packaging and container size are so powerful that they can increase our intake of foods that are less palatable.

DESIGN, SETTING, AND PARTICIPANTS

In a 2 x 2 between-subjects design, 158 moviegoers in Philadelphia (57.6% male; 28.7 years) were randomly given a medium (120 g) or a large (240 g) container of free popcorn that was either fresh or stale (14 days old). Following the movie, consumption measures were taken, along with measures of perceived taste.

OUTCOME MEASURES AND RESULTS

Moviegoers who were given fresh popcorn ate 45.3% more popcorn when it was given to them in large containers. This container-size influence is so powerful that even when the popcorn was disliked, people still ate 33.6% more popcorn when eating from a large container than from a medium-size container.

CONCLUSIONS AND IMPLICATIONS

Even when foods are not palatable, large packages and containers can lead to overeating. The silver lining of these findings may be that portion size can also be used to increase the consumption of less preferred healthful foods, such as raw vegetables.

Ice cream illusions bowls, spoons, and self-served portion sizes

BACKGROUND

Because people eat most of what they serve themselves, any contextual cues that lead them to over-serve should lead them to over-eat. In building on the size-contrast illusion, this research examines whether the size of a bowl or serving spoon unknowingly biases how much a person serves and eats.

METHODS

The 2 x 2 between-subjects design involved 85 nutrition experts who were attending an ice cream social to celebrate the success of a colleague in 2002. They were randomly given either a smaller (17 oz) or a larger (34 oz) bowl and either a smaller (2 oz) or larger (3 oz) ice cream scoop. After serving themselves, they completed a brief survey as their ice cream was weighed. The analysis was conducted in 2003.

RESULTS

Even when nutrition experts were given a larger bowl, they served themselves 31.0% more (6.25 vs 4.77 oz, F(1, 80) = 8.05, p < 0.01) without being aware of it. Their servings increased by 14.5% when they were given a larger serving spoon (5.77 vs 5.04 oz, F(1, 80)=2.70, p = 0.10).

CONCLUSIONS

People could try using the size of their bowls and possibly serving spoons to help them better control how much they consume. Those interested in losing weight should use smaller bowls and spoons, while those needing to gain weight--such as the undernourished or aged--could be encouraged to use larger ones. Epidemiologic implications are discussed.

The office candy dish: proximity's influence on estimated and actual consumption

OBJECTIVE AND PURPOSE

Although there is increasing interest in how environmental factors influence food intake, there are mixed results and misunderstandings of how proximity and visibility influence consumption volume and contribute to obesity. The objective of this paper is to examine two questions: first, how does the proximity and salience of a food influence consumption volume? Second, are proximate foods consumed more frequently because they are proximate, or are they consumed more frequently because people lose track of how much they eat?

RESEARCH METHODS AND PROCEDURES

The 4-week study involved the chocolate candy consumption of 40 adult secretaries. The study utilized a 2 x 2 within-subject design where candy proximity was crossed with visibility. Proximity was manipulated by placing the chocolates on the desk of the participant or 2 m from the desk. Visibility was manipulated by placing the chocolates in covered bowls that were either clear or opaque. Chocolates were replenished each evening, and placement conditions were rotated every Monday. Daily consumption was noted and follow-up questionnaires were distributed and analyzed.

RESULTS

There were main effects for both proximity and visibility. People ate an average of 2.2 more candies each day when they were visible, and 1.8 candies more when they were proximately placed on their desk vs 2 m away. It is important to note, however, that there was a significant tendency for participants to consistently underestimate their daily consumption of proximately placed candies (-0.9) and overestimate their daily consumption of less proximately placed candies (+0.5).

DISCUSSION

These results show that the proximity and visibility of a food can consistently increase an adult's consumption of it. In addition, these results suggest that people may be biased to overestimate the consumption of foods that are less proximate, and to underestimate those that are more proximate. Knowing about these deviation tendencies is important for those attempting effectively monitor their consumption of fat and sugar.

Attractive names sustain increased vegetable intake in schools

OBJECTIVE

This study will determine if the selective use of attractive names can be a sustainable, scalable means to increase the selection of vegetables in school lunchrooms.

METHODS

Study 1 paired an attractive name with carrots in five elementary schools (n=147) and measured selection and consumption over a week compared to controls. Study 2 tracked food sales of vegetables in two elementary schools (n=1017) that were systematically attractively named or not named over a two-month period. Both studies were conducted in New York in 2011.

RESULTS

Study 1 found that elementary students ate twice the percentage of their carrots if attractively named as "X-ray Vision Carrots," than if un-named or generically named as the "Food of the Day." Study 2 found that elementary school students were 16% more likely to persistently choose more hot vegetable dishes (p<0.001) when they were given fun or attractive names.

DISCUSSION

Attractive names effectively and persistently increased healthy food consumption in elementary schools. The scalability of this is underscored by the success of Study 2, which was implemented and executed for negligible cost by a high school student volunteer.

Meal size, not body size, explains errors in estimating the calorie content of meals

BACKGROUND

Although most people underestimate the calories they consume during a meal or during the day, calorie underestimation is especially extreme among overweight persons. The reason for this systematic bias is unknown.

OBJECTIVE

To investigate whether the association between calorie underestimation and body mass reflects a tendency for all persons to underestimate calories as the size of a meal increases.

DESIGN

Overweight and normal-weight adults estimated the number of calories of a fast-food meal they had ordered and eaten (study 1) or of 15 fast-food meals that were chosen by the experimenter (study 2) in a randomized, controlled trial. Their estimations were compared with the actual number of calories of the meals.

SETTING

Study 1 was a field study conducted in fast-food restaurants in 3 medium-sized midwestern U.S. cities. Study 2 was conducted in a laboratory at a major U.S. research university.

PARTICIPANTS

Study 1 involved 105 lunchtime diners (average body mass index [BMI], 24.2 kg/m2 [range, 17.2 to 33.5 kg/m2]). Study 2 involved 40 undergraduate students (average BMI, 23.2 kg/m2 [range, 16.1 to 32.3 kg/m2]).

MEASUREMENTS

Participants were asked to estimate the number of calories in a fast-food meal they had ordered and eaten (study 1) or in 15 sizes of the same fast-food meal (study 2). The actual number of calories in the meals in the field study was obtained by unobtrusively recording the food that was ordered (identified from the wrappings and containers). Weight and height were self-reported.

RESULTS

Although participants strongly underestimated the number of calories in larger meals (by -38.0% in study 1 and by -22.6% in study 2), they almost perfectly estimated the number of calories in smaller meals (by -2.9% in study 1 and by 3.0% in study 2). After the authors controlled for body weight-related differences in meal size, the calorie estimations of normal-weight and overweight participants were identical in both studies.

LIMITATIONS

These studies examined fast-food meals. Weight and height were self-reported. There were too few observations to distinguish between obese (BMI > or =30 kg/m2) and overweight (BMI >25 kg/m2 but <30 kg/m2) participants.

CONCLUSIONS

Greater underestimation of calories by overweight persons is a consequence of their tendency to consume larger meals. Calorie underestimation is related to meal size, not body size.

Smarter lunchrooms can address new school lunchroom guidelines and childhood obesity

New US Department of Agriculture regulations have altered what foods schools offer for lunch, but schools cannot require students to eat specific foods. An intervention using the behavioral science principle known as "libertarian paternalism" led junior-senior high school students to eat more fruits and vegetables by making these foods more convenient, attractive, and normative.

Pre-sliced fruit in school cafeterias: children's selection and intake

BACKGROUND

It is often assumed that children avoid fruit in school cafeterias because of higher relative prices and preferences for other foods. Interviews with children reveal that eating whole fresh fruit can be difficult for those with small mouths or braces. Older girls find whole fruits messy and unattractive to eat.

PURPOSE

To determine the effect of offering pre-sliced fruit in schools on selection and intake.

DESIGN

Three of six schools were assigned randomly to serve apples in slices. Three control schools served apples whole. Selection, consumption, and waste of apples were measured prior to and during treatment.

SETTING/PARTICIPANTS

Cafeterias in six public middle schools in Wayne County NY in 2011. Participants included all students who purchased lunch on days when data were collected.

INTERVENTION

Treatment schools were provided with a standard commercial fruit slicer, and cafeteria staff members were instructed to use it when students requested apples. Trained researchers recorded how much of each apple was consumed and how much was wasted in both control and treatment schools.

MAIN OUTCOME MEASURES

Daily apple sales, percentage of an apple serving consumed per student, and percentage of an apple serving wasted per student.

RESULTS

Data were analyzed in 2012. Schools that used fruit slicers to pre-slice fruit increased average daily apple sales by 71% compared to control schools (p<0.01). The percentage of students who selected apples and ate more than half increased by 73% (p=0.02) at schools that served pre-sliced fruit, and the percentage that wasted half or more decreased by 48% (p=0.03).

CONCLUSIONS

Sliced fruit is more appealing to children than whole fruit because it is easier and tidier to eat. This study applies the principle of convenience from behavioral economics and provides an example of a scalable, low-cost environmental change that promotes healthy eating and decreases waste.

Internal and external cues of meal cessation: the French paradox redux?

OBJECTIVE

Our objective was to investigate whether people who use internal cues of satiation when eating a meal are likely to weigh less than people who instead rely on external cues. In addition to exploring the role that internal and external cues play in meal cessation, this study raises an overlooked explanation of the French paradox.

RESEARCH METHODS AND PROCEDURES

A demographically-matched student sample of 133 Parisians and 145 Chicagoans completed a brief survey on meal cessation that asked the extent to which they agreed with statements associated with internal cessation cues and statements with external cessation cues. Their answers to these were compared across BMI levels and across countries.

RESULTS

Normal-weight people indicated that they were more likely to be influenced by internal cues of meal cessation (p = 0.043), while overweight people indicated that they were more influenced by external cues (p = 0.005). Similarly, while the French were influenced by internal cues of meal cessation (p < 0.001), Americans were more influenced by external cues (p < 0.001).

DISCUSSION

This research revisits Schachter's externality hypothesis and suggests that one's over-reliance on external cues may prove useful in offering a partial explanation of why BMI might vary across people and potentially across cultures. Relying on internal cues for meal cessation, rather than on external cues, may improve eating patterns over the long term.

Factors related to sustained use of a free mobile app for dietary self-monitoring with photography and peer feedback: retrospective cohort study

BACKGROUND

Healthy eating interventions that use behavior change techniques such as self-monitoring and feedback have been associated with stronger effects. Mobile apps can make dietary self-monitoring easy with photography and potentially reach huge populations.

OBJECTIVE

The aim of the study was to assess the factors related to sustained use of a free mobile app ("The Eatery") that promotes healthy eating through photographic dietary self-monitoring and peer feedback.

METHODS

A retrospective analysis was conducted on the sample of 189,770 people who had downloaded the app and used it at least once between October 2011 and April 2012. Adherence was defined based on frequency and duration of self-monitoring. People who had taken more than one picture were classified as "Users" and people with one or no pictures as "Dropouts". Users who had taken at least 10 pictures and used the app for at least one week were classified as "Actives", Users with 2-9 pictures as "Semi-actives", and Dropouts with one picture as "Non-actives". The associations between adherence, registration time, dietary preferences, and peer feedback were examined. Changes in healthiness ratings over time were analyzed among Actives.

RESULTS

Overall adherence was low-only 2.58% (4895/189,770) used the app actively. The day of week and time of day the app was initially used was associated with adherence, where 20.28% (5237/25,820) of Users had started using the app during the daytime on weekdays, in comparison to 15.34% (24,718/161,113) of Dropouts. Users with strict diets were more likely to be Active (14.31%, 900/6291) than those who had not defined any diet (3.99%, 742/18,590), said they ate everything (9.47%, 3040/32,090), or reported some other diet (11.85%, 213/1798) (χ(2) 3=826.6, P<.001). The average healthiness rating from peers for the first picture was higher for Active users (0.55) than for Semi-actives (0.52) or Non-actives (0.49) (F2,58167=225.9, P<.001). Actives wrote more often a textual description for the first picture than Semi-actives or Non-actives (χ(2) 2=3515.1, P<.001). Feedback beyond ratings was relatively infrequent: 3.83% (15,247/398,228) of pictures received comments and 15.39% (61,299/398,228) received "likes" from other users. Actives were more likely to have at least one comment or one "like" for their pictures than Semi-actives or Non-actives (χ(2) 2=343.6, P<.001, and χ(2) 2=909.6, P<.001, respectively). Only 9.89% (481/4863) of Active users had a positive trend in their average healthiness ratings.

CONCLUSIONS

Most people who tried out this free mobile app for dietary self-monitoring did not continue using it actively and those who did may already have been healthy eaters. Hence, the societal impact of such apps may remain small if they fail to reach those who would be most in need of dietary changes. Incorporating additional self-regulation techniques such as goal-setting and intention formation into the app could potentially increase user engagement and promote sustained use.

Slim by design: serving healthy foods first in buffet lines improves overall meal selection

OBJECTIVE

Each day, tens of millions of restaurant goers, conference attendees, college students, military personnel, and school children serve themselves at buffets--many being all-you-can-eat buffets. Knowing how the food order at a buffet triggers what a person selects could be useful in guiding diners to make healthier selections.

METHOD

The breakfast food selections of 124 health conference attendees were tallied at two separate seven-item buffet lines (which included cheesy eggs, potatoes, bacon, cinnamon rolls, low-fat granola, low-fat yogurt, and fruit). The food order between the two lines was reversed (least healthy to most healthy, and vise-versa). Participants were randomly assigned to choose their meal from one line or the other, and researchers recorded what participants selected.

RESULTS

With buffet foods, the first ones seen are the ones most selected. Over 75% of diners selected the first food they saw, and the first three foods a person encountered in the buffet comprised 66% of all the foods they took. Serving the less healthy foods first led diners to take 31% more total food items (p<0.001). Indeed, diners in this line more frequently chose less healthy foods in combinations, such as cheesy eggs and bacon (r = 0.47; p<0.001) or cheesy eggs and fried potatoes (r= 0.37; p<0.001). This co-selection of healthier foods was less common.

CONCLUSIONS

Three words summarize these results: First foods most. What ends up on a buffet diner's plate is dramatically determined by the presentation order of food. Rearranging food order from healthiest to least healthy can nudge unknowing or even resistant diners toward a healthier meal, helping make them slim by design. Health-conscious diners, can proactively start at the healthier end of the line, and this same basic principle of "first foods most" may be relevant in other contexts - such as when serving or passing food at family dinners.