Healthy eating and restaurants . A review of recent evidence in the literature

Food environments influence food consumption and population health. This study sought to establish the outstanding themes in recent scientific literature about healthy eating and restaurants. Studies about the topic published from 2011 to 2016 in seven recognized databases were reviewed systematically. From 999 titles, 20 articles were selected. Content analysis through an inductive method by two independent investigators was performed using Nvivo 10.0. Three dominant subjects were identified: Food supply modifications, promotion of healthy choices and barriers against healthy eating promotion. The findings describe research opportunities in the area, particularly in the Latin American context. It is necessary to make interventions that result in healthy food environments given the impact on collective health.


introduction
Nowadays a large proportion of the population regularly consumes meals away fromhome 1 .In fact, in countries such as the United States (U.S.), individuals spend half of every dollar on out-ofhome food 2 .In comparison, in 2009 the Brazilian population spent a third of its food budget at food establishments, while in 2002 they only spent24% 3 .This illustrates the growth in food consumption at restaurants.Consequently, these places have an important impact not only on the economy, but also on food consumption.From an economic point of view, the foodservice industry generates more than 500 billion transactions per day 4 .On the other hand, one-third of the population's daily energy consumption comes from fast food shops, restaurants and other food establishments 5 .
Eating places creates cenarios for making food choices and influencing collective health; for example, the World Health Organization (WHO) addresses out-of-home food as an environmental determinant of health 6 .Specifically, food environments can be broadly conceptualized as any opportunity to obtain food at or away from home 7 .However, in the case of food consumption away from home, elements are considered related to marketing, advertising, access, geographical availability, among others.Particularly, Minaker et al. 8 point out that geographic access to food sources as well as marketing within those sources are associated with dietary behaviors and downstream effects on health status.Similarly, other scientific reports show that environments influence food consumption 9 .Due to these factors, it is recognized that restaurants generate conditions in which food is found and choices are made.
It would be expected that food choices made by individuals away from home maximize their wellness, particularly considering the relationship between health and food intake.For this reason, a balanced diet is included in several strategies to generate optimal conditions for growth and development in childhood 10 , productivity in adult life 11 , and active aging 12 .To illustrate this, from a public health perspective, multiple dietary guidelines are implemented for different countries to give recommendations for a balanced diet among their populations.Examples are the guidelines developed in countries such as Mexico 13 , Argentina 14 or Colombia 15 .However, choosing meals in food establishments is determined by other economic, physical and social variables.
In fact, food consumption decisions involve a multifactorial process.In the case of the decisions made in restaurants, they are influenced by price promotion, characteristics of products, physical layout, among others 16 .
Given the exposed relationships and the complexity of food choices in out-of-home environments, there is a need to establish ways to promote healthy eating in food establishments, particularly in restaurants, due to their availability in urban areas and their economic impact.Consequently, the objective of this study was to identify relevant topics in the recent scientific literature about healthy eating and restaurants.A systematic review of research in this area published between 2011 and 2016 was conducted, which resulted in updated research on the subject as well as opportunities to influence collective health.

Methods
The review considered scientific articles published from January 1,2011 to April 30, 2016.Seven databases were consulted: Web of Science, Scopus, PubMed, Ebsco Host (Medline full text), Science Direct (Elsevier), Redalyc and Dialnet.The pre-defined search terms and text words used across all the databases included: "Healthy eating" AND "Choices" AND "Restaurants"; "Healthy eating" AND "Choices" AND "Food service"; "Healthy eating" AND "Dining" AND "Food service"; "Healthy eating" AND "Dining" AND "Restaurants"; "Healthy" AND "Offer" AND "Food service"; "Healthy" AND "Offer" AND "Restaurants"; "Healthy food" AND "Food service"; "Healthy food" AND "Restaurant"; "Healthy offers" AND "Food service"; "Healthy offers" AND "Restaurant".
Documents were eligible for inclusion if (1) they addressed healthy eating in restaurants; (2) they were presented in research articles or reviews; and (3) they were written either in English or Spanish.First, documents were identified through search terms and filters on the databases.Following this, titles and abstracts were screened for inclusion based on the eligibility criteria.Finally, the full-text records were read to select the documents that were part of this literature review.
The articles included in the final sample were recorded in a data table, which listed title, year and country of publication, study place, type of study, objective, summary of results, main ideas of discussion and conclusions.Additionally, for those who had a more extensive description of healthy eating in restaurants, analytical summaries were written.The selection of the documents, the registration in the data table and the preparation of analytical summaries were carried out by the two authors.
Content analyses of the data table and summaries were independently conducted by the authors using NVivo 10.0.First, the information was coded focusing on healthy eating criteria used in the studies as well as descriptions of interventions to promote healthy eating and their effectiveness.After that, emerging themes were identified, and similarities and differences between articles were analyzed.Disagreements among the researchers were settled through discussion until consensus was reached.Recurrence tables, flowcharts and cloud maps were used to target dominant subjects.Eventually, narrative syntheses with the predominant topics were written.The topics included were those repetitive in the literature, those that contributed to understanding healthy eating promotion in restaurants or those that had a strong relationship with recognized dietary guidelines.

results
This review included 20 documents published between 2011 and 2016 in well-known scientific databases.Figure 1 shows the selection process of the articles included in this study.
From the selected articles, 50% of the studies were completed in U.S. and 20% in the United Kingdom (4 articles).In contrast, only one study was conducted in Latin America, specifically in Brazil.The documents included experimental investigation (65%) and descriptive studies (20%), and only three (15%) were the result of reviews.Chart 1 shows the 20 review articles.
From the content analysis, three relevant themes emerged: Food supply modifications, promotion of healthy choices and barriers against healthy eating promotion in restaurants.Each of them is described in a narrative synthesis below.

Food supply modifications
In the studies included, there was a clear statement about the importance of environmental factors over health promotion.Researchers such as Caraher et al. 17 , Martínez-Donate et al. 18 and Skov et al. 19 described health behaviors as the result of interaction between individuals' attributes and environmental factors, like food availability in restaurants.For this reason, they pointed out the need to adjust food supply in these establishments.Specifically, inclusion of health-friendly options in menus was a recurrent topic, mentioning fruits and vegetables as a regular example 4,18,[20][21][22][23][24][25] .Predominantly, concern was expressed about providing meals that contribute to wellness, given the close relationship between food consumption and health.
Other food supply modifications were justified by the link between high intake of specific nutrients and prevalence of chronic diseases.For this reason, reduction of unhealthy options in menus was recommended in different studies.Particularly, an important percentage of documents referred to the need to include meals with a low calorie count due to the obesity epidemic.According to the articles, low calorie dishes may be included in restaurants' menus through modifying cooking methods 4,20,22,24 , reducing portion size 4,17,19,20,[22][23][24] or adding appetizers with lower calories 4,18,23,24 .Likewise, sugar reduction in meals offered in these establishments was discussed 4,17,20,22,26,27 .On the other hand, reduction of sodium and saturated fat was mentioned repeatedly due to the high prevalence of cardiovascular disease in the population 4,20,24,[27][28][29] .For example, the study led by Bagwell proposed to eliminate salt shakers from the tables and reduce salt addition during cooking 20 .In this way, it was highlighted that restaurants may contribute to the prevention of prevalent chronic diseases.

Promotion of healthy choices
According to the documents reviewed, it is crucial not only to modify the food supply, but also to favor healthy decisions by consumers in restaurants.Specifically, the articles referred to strategies such as providing information at points of sale, events and sales promotions.In terms of information to promote healthy choices, menu labeling to show nutrition facts was recurrently mentioned [17][18][19][21][22][23][30][31][32][33] . This consides that awareness of calorie content of meals would influence mindful food choices.Also, informative slogans to highlight healthier items 18,22 , communication through information technologies 18,21 and logos to promote nutritious food were suggested 18,19,22,34 .Alternatively, only one study referred to verbal guidelines given by servers as a communication tactic 25 .
Regarding events and sales promotions to facilitate healthier behaviors in restaurants, a small-er number of publications referred to these strategies.In the case of events, local initiatives with awards to "healthy" caterers 20 and competitions around better food choices between customers 30 were mentioned.Regarding sales promotion, the literature referred to interventions in means of payment 19 , lower prices for nutritious food 22 and product bundling 18,[21][22][23] -all to persuade consumers to make healthier choices.

Barriers against healthy eating promotion in restaurants
Although the literature reported different initiatives to encourage healthy eating in restaurants, the obstacles were clearly highlighted, specifically barriers associated with consumer perception and profitability of healthier food supply.Some of the articles discussed the low popularity of and reduced demand for healthy foods among clients due to less pleasant flavor 17,19,20,22 .To illustrate this, Newson et al. 4 asserted that healthy choices are often linked to the perception of less taste, less satiety and higher price.Given this trend, several establishments assume that providing this type of food will harm their profits 22,34 , even more so if foods with lower nutritional quality have a higher profit margin 25,26 .In fact, one study indicated a potential conflict between health promotion and profit generation in food outlets 35 .For instance, offering healthy ingredients represents a higher cost that not all customers are willing to pay for 17,20 .Similarly, reducing portion sizes may affect price and restaurants' incomes as well 20,25 .However, other authors asserted that healthy eating promotion may be commercially interesting, considering a new market of health-conscious consumers 34 .Articles identified through searching in the databases (n=999) Articles excluded from titles (n=584) Articles screened using abstracts (n=415) Full-text articles excluded (n=41): Healthy eating in restaurants was not addressed in depth (n=19); preliminary articles without conclusive results (n=6); Focus only on public policies or institucional or business plans about healthy eating (n=3); focus on institucional foodservices (n=5); focus on consumer perceptions about healthy eating in general (n=8).
Full-text articles assessed for elegibility (n=61) Articles included in the review (n=20)

Discussion
This review provides updated literature regarding healthy eating in restaurants and research opportunities.For instance, minimal research was found in Latin American countries.In fact, one study pointed out that even though U.S. research has provided information on the topic, other countries may face unique food environment issues 8 .Given differences in economy and cul- ture, it is imperative to study these environments in different contexts.However, developing valid scales and instruments for evaluation is part of the challenge.For example, in the review, there were not specific tools reported.In contrast, the literature about institutional foodservices refers to the "Nutrition Environments Survey" (NEMRS) as a valid checklist to evaluate healthy eating promotion [36][37][38][39] .Nevertheless, that survey has different versions, and one of them already is used in restaurants 40 .Although there are numerous studies about healthy diets in institutional food services like workplaces, gardens, hospitals, among others [41][42][43][44] , still there are few in restaurants, despite higher decision-making power of the consumer in these establishments.Therefore, characterizing and intervening in food supply in restaurants represents a research opportunity.
Regarding the findings, some of them are congruent with public health concerns and other scientific evidence.In the case of calorie reduction in restaurants' meals, this strategy is justified by findings about obesogenic factors.For example, previous studies emphasize that eating away from home impacts caloric intake and weight gain [45][46][47] .This explains the relationship between obesity and environmental aspects 48 .Given that overweight and obesity are common and serious problemsnowadays 49 , intervention over calorie count in restaurants may contribute to the solution.
The prevalence in non-communicable diseases (NCDs)explained our findings in reference to interventions in sugar, sodium and saturated fat in restaurants' meals.In 2015, WHO reported that 38 million people around the world die each year from conditions such as cardiovascular disease, respiratory disease, diabetes or cancer 50 .Such diseases were caused by inadequate eating habits among other factors 51 .That is why diet has become an important factor to prevent these diseases.There is enough evidence about the relationship between excess salt intake and cardiovascular disease [52][53][54] ,or about high-sugar consumption and cellular deterioration, diabetes and cardiovascular disease [55][56][57] .For this reason, the Global Action Plan for the Prevention and Control of NCDs describes the need to regulate sugar, sodium and saturated fat in population diet 58 .Therefore, food supply modifications regarding these nutrients are fundamental to respond to public health concerns.
Increased availability of fruits and vegetables in restaurants' menus may promote healthier population eating patterns.Consumption of fruits and vegetables is recognized as part of a healthy diet.A balanced diet is recognized as fundamental for maintaining health.The Scientific Report of the Dietary Guidelines for the United States, in 2015, considered healthy eating as one of the pillars of well-being during life 9 .In the case of fruits and vegetables, they are associated with numerous health benefits.For example, they are rich in fiber that favors gastrointestinal well-being and reduces absorption of nutrients like carbohydrates 62 .Similarly, fruits and vegetables provide secondary metabolites with antioxidants and vasodilatoreffects [59][60][61] that are crucial to cardiovascular performance.In light of these benefits, the recurrent allusion to the importance fruits and vegetables' availability in restaurants is validated.
Despite awareness of the relevance of a healthy diet, the findings showed a misalignment with recent definitions of healthy eating.Today, the definitions include an approach to both food and nutrients aimed at optimizing health, which not only addresses the consumption of fruits and vegetables and discourages the consumption of food sources with nutrients related to disease.It is also necessary to include healthy fats, whole grains, nuts and water and moderate alcohol consumption [63][64][65][66] .In our literature review, only one article referred to healthy fats, whole grains and water 20 .In fact, the principal focus was fruits and vegetables.Thus, there is room for progress to a holistic approach about what healthy eating may bein restaurants.
Our findings point out not only the importance of food supply modification in restaurants, but also the promotion of healthy food choices.Particularly, it is recommended that food establishments provide support, access to information and opportunities to make healthy decisions.An example of this kind of support is the menu-labeling strategy.In 2006, the State of New York in the U.S. made calorie labels compulsory in certain restaurant chains 67 .Nevertheless, the findings about its effectiveness are still ambiguous [68][69][70] .Different tactics to promote healthier food decisions in restaurants still need to be studied, even more in the case of countries where there is no such regulation.
One may assume that healthy eating is not, in a strict sense, an issue that should be addressed by restaurants.Food establishments create conditions for food consumption.Consequently, they are responsible for these conditions and their impact on collective health.In fact, the Ottawa Charter states that health promotion is not only the responsibility of the health sector, and that actions from other economic and social sectors are required 71 .Similarly, other authors remark that it is crucial that the foodservice industry take responsibility for the health of customers 1 .However, deep work with the population and their perceptions about healthy food is also required.Restaurants can help in this effort as well.For example, developing appealing healthy dishes may affect perceptions.Nowadays, taste is well known as a decision-making trigger for food choices [72][73][74][75][76][77][78][79] .Therefore, attractive healthy meals may positively influence their consumption and perceptions.On the other hand, restaurants could profitably help clients make healthier choices, considering a higher demand of healthy options recently 80,81 .In other words, a collective effort is necessary with benefits for customers and restaurants.
Even though this study provides updated research on healthy eating in restaurants, it has limitations as well.Particularly, we did not evaluate methods and designs of the studies included.Future studies are needed to explore the integrity of measures and study designs in this field.Similarly, we did not include documents about public policies on this topic.However, it is well known that there are opportunities for governments to regulate marketing in restaurants and create healthier food environments 65,[82][83][84] .Nowadays, restaurants are recognized as ideal settings to promote health.In fact, they are part of future lines of research in reports like the U.S. Nutrition Research Plan 2016-2021 or the Scientific Report of the U.S. Dietary Guidelines, from 2015 9,85 .Therefore, with the dominant subjects identified, research in Latin America may also establish an academic agenda to explore the topic in our countries.

Conclusion
The literature review presented three dominant subjects regarding healthy eating in restaurants, specifically, food supply modifications, promotion of healthy choices and barriers against healthy eating in these establishments.So far, food environments and restaurants have been principally studied in countries like the United States or the United Kingdom, while there is a need to research them more in Latin American countries.The studies examined pointed out the importance of different strategies to promote healthier food environments, given their impact on collective health.

Figure 1 .
Figure 1.Selection process of the articles.Source: Author's data.