***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND The federal menu labeling law will require chain restaurants to post caloric information on menus , but the impact of labeling is uncertain . PURPOSE The goal of the current study was to examine the effect of menu labeling on calories purchased , and secondarily , to assess self-reported awareness and use of labels . DESIGN Single-community pre-post-post cross-sectional study . Data were collected in 2008 - 2010 and analyzed in 2011 - 2012 . SETTING / PARTICIPANTS 50 sites from 10 chain restaurants in King County , Washington , selected through stratified , two-stage cluster r and om sampling . A total of 7325 customers participated . Eligibility criteria were : being an English speaker , aged ≥ 14 years , and having an itemized receipt . The study population was 59 % male , 76 % white non-Hispanic , and 53 % aged<40 years . INTERVENTION A regulation requiring chain restaurants to post calorie information on menus or menu boards was implemented . MAIN OUTCOME MEASURES Mean number of calories purchased . RESULTS No significant changes occurred between baseline and 4 - 6 months postregulation . Mean calories per purchase decreased from 908.5 to 870.4 at 18 months post-implementation ( 38 kcal , 95 % CI=-76.9 , 0.8 , p=0.06 ) in food chains and from 154.3 to 132.1 ( 22 kcal , 95 % CI=-35.8 , -8.5 , p=0.002 ) in coffee chains . Calories decreased in taco and coffee chains , but not in burger and s and wich establishments . They decreased more among women than men in coffee chains . Awareness of labels increased from 18.8 % to 61.7 % in food chains and from 4.4 % to 30.0 % in coffee chains ( both p<0.001 ) . Among customers seeing calorie information , the proportion using it ( about one third ) did not change substantially over time . After implementation , food chain customers using information purchased on average fewer calories compared to those seeing but not using ( difference=143.2 kcal , p<0.001 ) and those not seeing ( difference=135.5 kcal , p<0.001 ) such information . CONCLUSIONS Mean calories per purchase decreased 18 months after implementation of menu labeling in some restaurant chains and among women but not men Background Interpretive front-of-pack nutrition labels are better understood than non-interpretive labels . However , robust evidence on the effects of such labels on consumer food purchases in the real-world is lacking . Our aim is to assess the effects of two interpretive front-of-pack nutrition labels , compared with a non-interpretive label , on the healthiness of consumer food purchases . Methods / Design A five-week ( 1-week baseline and 4-week intervention ) three-arm parallel r and omised controlled trial will be conducted using a bespoke smartphone application , which will administer study question naires and deliver intervention ( Multiple Traffic Light and Health Star Rating ) and control ( Nutrition Information Panel ) labels . To view their allocated nutrition label , participants scan the barcode of packaged food products using their smartphone camera . The assigned label is displayed instantly on the smartphone screen.1500 eligible participants ( New Zeal and adult smartphone owners who shop in a supermarket at least once a week and are main household shoppers ) will be r and omised in a 1:1:1 ratio to one of the three nutrition label formats , using computer-generated r and omisation sequences . R and omisation will be stratified by ethnicity and interest in healthy eating . Food and beverage purchase data will be collected continuously throughout the study via hard copy till receipts and electronic grocery purchase lists recorded and transmitted using the smartphone application . The primary outcome will be healthiness of food purchases in each trial arm , assessed as mean Food St and ards Australia New Zeal and nutrient profiling score criterion score for all food and beverages purchased over the intervention period . Secondary outcomes will include saturated fat , sugar , sodium and energy content of food purchases ; food expenditure ; labelling profile of food purchases ( i.e. mean number of Health Star Rating stars and proportion of red , green and amber traffic lights ) ; nutrient profiling score over time and by food categories ; purchases of unpackaged foods ; self-reported nutrition knowledge and recorded use of assigned labelling system . Discussion The Starlight r and omised , controlled trial will determine the effects of interpretive front-of-pack nutrition labels on the healthiness of consumer food purchases in the real world . Trial registration Australian New Zeal and Clinical Trials Registry ACTRN12614000644662 ( registered 18 June 2014 ) This study investigated the effectiveness of labeling foods with the Choices nutrition logo on influencing cafeteria menu selection and the behavioral determinants of menu choices in work site cafeterias in the Netherl and s. A cluster r and omized controlled trial was conducted .  Intervention cafeterias ( n=13 ) , where the Choices logo was used to promote healthier eating for a 3-week period , were compared with control cafeterias ( n=12 ) , which offered the same menu without the logo .  Sales data were collected daily for 9 weeks , from March to May 2009 . In addition , employees from one intervention and one control company completed an online question naire at baseline and after the intervention ( n=368 ) in which the behavioral determinants of food choice ( ie , attitude , self-efficacy , and intention ) and logo use were measured . Generalized estimating equation analyses , χ² tests , t tests and linear regression analyses were performed . No nutritionally meaningful intervention effects were found in the sales of s and wiches , soups , snacks , fruit , and salads . Also , no significant differences in behavioral determinants were found . " Intention to eat healthier " and " paying attention to product information " were positively associated with self-reported consumption of foods with the Choices logo at lunch . The intervention did not have a significant effect on employees ' lunchtime food choices . Labeling healthy choices might be useful for health-conscious employees in the volitional phase of behavior change . Further research should focus on the possible health benefits of menu reformulation in the catering sector The influence of information about the fat content of food and cardiovascular disease ( CVD ) prevention on taste ratings and food intake in a test meal was examined . Forty Ss were allocated at r and om to CVD information or control conditions . Ss rated 2 br and s of yogurt and 2 cheese s and wiches , with 1 flavor of each food labeled full-fat and the other low-fat . In fact , fat levels were identical , and the label-flavor pairings were counterbalanced . Overall , Ss gave lower liking ratings to the low-fat labeled foods . However , Ss in the information condition tended to eat a smaller proportion of the full-fat s and wiches . The results supported the utility of a laboratory setting for evaluating the influence of health-relevant information on responses to food Objective Obesity is a pressing public health problem without proven population -wide solutions . Research ers sought to determine whether a city-m and ated policy requiring calorie labeling at fast food restaurants was associated with consumer awareness of labels , calories purchased and fast food restaurant visits . Design and Methods Difference-in-differences design , with data collected from consumers outside fast food restaurants and via a r and om digit dial telephone survey , before ( December 2009 ) and after ( June 2010 ) labeling in Philadelphia ( which implemented m and atory labeling ) and Baltimore ( matched comparison city ) . Measures included : self-reported use of calorie information , calories purchased determined via fast food receipts , and self-reported weekly fast-food visits . Results The consumer sample was predominantly Black ( 71 % ) , and high school educated ( 62 % ) . Post-labeling , 38 % of Philadelphia consumers noticed the calorie labels for a 33 percentage point ( p<.001 ) increase relative to Baltimore . Calories purchased and number of fast food visits did not change in either city over time . Conclusions While some consumer reports noticing and using calorie information , no population level changes were noted in calories purchased or fast food visits . Other controlled studies are needed to examine the longer term impact of labeling as it becomes national law Increased visibility of food labels is a potential method to reduce the rate of obesity . However , few empirical studies have investigated the impact of nutrition labeling on food selection or energy intake . This study tested the hypothesis that nutrition labeling in combination with nutrition label education would promote reductions in energy intake using a laboratory-based paradigm . Forty-seven male ( n=24 ) and female ( n=23 ) participants visited the Nutrition and Health Research Laboratory for a single lunch session during the months of May through August 2009 . Participants were r and omly assigned to one of two video groups ( Nutrition Labeling Education or Organic Food Movement ) and one of two labeling conditions ( Nutrition Labels or No Labels ) . Participants watched a short educational video and then consumed a buffet lunch . Data were analyzed using a three-way analysis of covariance with sex , video condition , and labeling group as the between-subject factors and age and race as covariates . There were main effects of sex and nutrition label condition on lunch energy intake with females consuming less than males and people with nutrition labels consuming less energy than those without , regardless of sex or video condition . Examination of energy intake from low-energy-density and high-energy-density foods showed that the nutrition labeling group consumed less energy from both low-energy-density and high-energy-density food sources . These data support the use of nutrition labels as a way to reduce energy intake The present study examined whether low-fat labeling and caloric information affect food intake , calorie estimates , taste preference , and health perceptions .  Participants included 175 female undergraduate students who were r and omly assigned to one of four experimental conditions . A 2 × 2 between subjects factorial design was used in which the fat content label and caloric information of chocolate c and y was manipulated . The differences in food intake across conditions did not reach statistical significance . However , participants significantly underestimated the calorie content of low-fat-labeled c and y. Participants also rated low-fat-labeled c and y as significantly better tasting when they had caloric information available . Participants endorsed more positive health attributions for low-fat-labeled c and y than for regular-labeled c and y , independent of caloric information . The inclusion of eating attitudes and behaviors as covariates did not alter the results . The study findings may be related to the " health halo " associated with low-fat foods and add to the research base by examining the interaction between low-fat and calorie labeling Purpose . Determine the effect of menu labels displaying the energy content of food items or the exercise equivalent on energy ordered and consumed at lunch and energy intake for the remainder of the day in young adults . Design . Subjects were r and omized to a menu with no labels ( no-labels ) , menu with kilocalorie labels displaying the energy content of the food items ( kcal-labels ) , or menu with exercise labels displaying the minutes of brisk walking needed to burn the food energy ( exercise-labels ) . Setting . The study was conducted in one dining area located in a metabolic kitchen at the Texas Christian University and another located in a residence occupied by graduate students . Subjects . Of the 300 subjects , 55.7 % were female , 77.3 % were college students , 88 % were white , and 88 % were non-Hispanic . Mean body mass index and age were 24.2 ± 4.5 kg/m2 and 21.9 ± 2.3 years , respectively . Intervention . All menus contained the same food/beverage choices . Subjects ordered and consumed foods/beverages for lunch from the menu to which they were assigned . Subjects were blinded to study purpose . Measures . Energy ordered and consumed at lunch were assessed from the weight of the food ordered and consumed , respectively , and the energy content of the same foods available on the restaurant Web site . Postlunch energy intake was assessed by food recall . Analysis . Analysis of covariance , adjusted for premeal hunger levels and gender , determined the effect of menu type on energy ordered and consumed and postlunch energy intake . Results . Significant menu effect was observed for energy ordered ( p = .008 ) and consumed ( p = .04 ) at lunch . The exercise-labels group ordered significantly ( p = .002 ) less energy ( adjusted mean [ confidence intervals ] : 763 [ 703 , 824 ] kcal ) at lunch , compared to the no-labels group ( 902 [ 840 , 963 ] kcal ) but not compared to the kcal-labels group ( 827 [ 766 , 888 ] kcal ) . The exercise-labels group also consumed significantly ( p = .01 ) less energy ( 673 [ 620 , 725 ] kcal ) at lunch , compared to the no-labels group ( 770 ( 717 , 823 ) kcal ) but not compared to the kcal-labels group ( 722 [ 669 , 776 ] kcal ) . Energy ordered and consumed were not different between kcal-labels and no-labels groups . There was no difference in postlunch energy intake by menu type . Conclusion . The menu with exercise-labels result ed in less energy ordered and consumed and this did not lead to greater energy consumption post lunch , compared to the menu with no-labels in young adults largely made up of normal-weight , non-Hispanic white college students ing test does not benefit a patient under all circumstances ; instead , proponents must show under what conditions it can work . If a patient is young ( < 60 years ) and has few comorbidities ; if a patient has extensive family history of prostate cancer ; if a patient is African American — 
    Output:
    
Authors ' conclusions Findings from a small body of low‐ quality evidence suggest that nutritional labelling comprising energy information on menus may reduce energy purchased in restaurants .
The evidence assessing the impact on consumption of energy information on menus or on a range of food options in laboratory setting s suggests a similar effect to that observed for purchasing , although the evidence is less definite and also of low quality .
Accordingly , and in the absence of observed harms , we tentatively suggest that nutritional labelling on menus in restaurants could be used as part of a wider set of measures to tackle obesity .