INTRODUCTION — Fast food restaurants or quick-service establishments are a common choice for purchasing food away from home [1-3]. Socioeconomic trends, such as longer work hours, more women employed outside of the home, and a high number of single-parent households have changed the way families obtain their meals [4-7]. As parents experience busier lifestyles, they demand convenience for their family meals. The consumption of fast food is fostered because of the quick service, convenience, good taste, and inexpensive prices relative to more traditional home-style restaurants [8,9].
This topic review will discuss the epidemiology and nutritional consequences of fast food consumption in children and adolescents, as well as influences that affect fast food intake and management strategies. Other dietary habits among adolescents are discussed separately. (See "Adolescent eating habits".)
TERMINOLOGY
●Fast food – The term "fast food" is typically used to describe the type of food that was traditionally provided at commercial, rapid-service restaurants such as McDonald's, Burger King, or Kentucky Fried Chicken. In the past, most of the foods available at these restaurants were unhealthy, with excessive content of calories, fat, and sodium (eg, burgers or fried foods, sugar-sweetened beverages, and sweet desserts). This is still the case for many but not all items sold at this type of establishment. (See 'Concerns' below.)
●Healthy fast-casual food service – Fast-casual food service is sometimes used to describe fast-service restaurants that typically market higher-quality, locally sourced and/or organic foods, with fewer highly processed or frozen ingredients compared with traditional fast-food chain restaurants. Menus in these restaurants often identify food selections that contain healthy fats and lower sodium content and provide modest portion sizes; they often list nutritional information adjacent to selections.
●Junk food – "Junk food" is a colloquial term, typically used to describe food that is unhealthy because it is high in calories from sugar or fat and low in components with nutritional value, such as dietary fiber, protein, vitamins, and minerals. The nutritional profile of these foods is sometimes described as "empty calories." Junk food may include some high-protein foods, such as meat prepared with saturated fat. Most junk food is highly processed.
These terms are used inconsistently, and there is substantial overlap between these categories. In particular, many traditional fast food establishments have modified their menus by offering lower-fat items in addition to traditional selections [10-12]. As a result, it is possible to order a healthier meal that provides a good supply of nutrients that children and adolescents need for growth and development [13]. Conversely, some items available at "healthy" fast-casual food service establishments are high in calories, fat, and sodium, similar to traditional "fast food." Thus, it is important to educate children and their families to be alert to the nutritional content of specific foods so that they can make healthier choices within any of the above categories. (See 'More nutritious fast food choices' below.)
BACKGROUND
Epidemiology — The National Restaurant Association estimates that the average American eats out an average of four times a week [14]. Approximately 36 percent of children and adolescents in the United States consume fast food on a typical day, providing on average approximately 14 percent of daily calories, and intake increases with age [15,16]. In the United States, more than 48 percent of today's food dollar is spent away from home, a value that has almost doubled over the past 50 years [17-19]. In non-metropolitan areas, adolescents and parents who live in towns with five or more fast food outlets were 30 percent more likely to eat fast food compared with those in towns with no fast food outlets [20]. The influence of in-town fast food outlets on fast food intake was strongest among families with low motor vehicle access. In contrast, fast food dining is less common when families have closer proximity and easier access to supermarkets [21]. Consumption of fast food is promoted by extensive advertising campaigns, including on social media, some of which target young children [22-29].
Increases in fast food consumption have been reported in other countries [30-32]. Longitudinal studies conducted among Chinese school-aged children show substantial increases in consumption of western-style fast food, particularly among adolescents, based on data obtained from the 2004 and 2009 Chinese Health and Nutrition Survey [33]. The increase in fast food consumption was observed among all age, gender, and family income groups. Fast food consumption is high in childhood and increases in adolescence [34].
Adverse health consequences of frequent fast food consumption — Establishment of healthy eating patterns in childhood is linked to a reduction in chronic diseases, such as obesity, coronary heart disease, hypertension, type 2 diabetes, osteoporosis, and diet-related cancers later in life [35-41]. Conversely, frequent consumption of fast food has adverse effects on nutrition because of excessive content of energy and fat and low nutritional value [15,42-46]. Proximity to fast food restaurants is associated with higher rates of obesity in the neighborhood [47]. Moreover, consumption of fast food is associated with other poor nutritional habits: Surveys show that parents who reported purchasing fast food for family meals at least three times per week were significantly more likely than parents who reported purchasing fewer than three fast food family meals to report the availability of soft drinks and chips in the home [48]. Of note, the "empty calorie" content (low nutritional value) of children's dietary intake from retail food stores and schools is similar to that of fast food restaurants. The source of added sugar and fat from retail food stores and schools, including sugar-sweetened beverages, grain desserts, pizza, and high-fat milk, was similar to that from fast food restaurants including high-fat milk beverages, dairy desserts, french fries, and pizza [49]. More importantly, children from middle and low social class backgrounds were more likely to report low intake of fruits and vegetables, given low exposure to supermarket food sources and high exposure to fast food outlets [50].
Educational strategies — Fast foods are a way of life for many American families, and eliminating fast foods may not be realistic. The challenge is to teach children and adolescents to make wise food choices when visiting fast food establishments. This is an important issue since the establishment of healthy eating patterns in childhood is linked to a reduction in chronic diseases, such as obesity, coronary heart disease, hypertension, type 2 diabetes, osteoporosis, and diet-related cancers later in life [35-41]. Healthful eating patterns for children over the age of two can be achieved by consumption of a prudent diet that is moderate in total fat, saturated fatty acids, and cholesterol and high in complex carbohydrates, fiber, calcium, and antioxidant nutrients such as vitamins C and E and the carotenoids [51-53]. (See "Dietary recommendations for toddlers, preschool, and school-age children" and "Dietary history and recommended dietary intake in children".)
To encourage children to learn healthy eating patterns, an important strategy is to limit children's exposure to fast food marketing messages. Targeting schools in low-income, urban neighborhoods is particularly important because of the increased availability of fast food restaurants in these areas [54]. Other strategies might include avoiding television networks that air child-directed advertisements for children's fast food meals with the collection of fast food meal toy premiums [55-57]. Active mediation of fast food marketing by parents can also help to reduce fast food consumption [58]. Greater educational achievement by mothers is associated with reduced fast food consumption in their children, suggesting that providing educational opportunities for women may improve nutrition in their offspring [59]. One Australian study showed that children were more likely to choose a healthier meal if the meal was advertised next to an appealing trailer for a movie [60].
NUTRITIONAL CONSIDERATIONS FOR FAST FOODS — "Junk food" is a descriptive term commonly associated with fast food. Although "junk food" has negative connotations, not all foods found in fast food restaurants contribute to adverse dietary lifestyles and eating habits. One meta-analysis reported a mixed relationship between fast food restaurants and weight-related behaviors and outcomes in children [61]. The extent to which fast foods influence the nutritional status of the child or adolescent depends upon several factors [62]:
●The nutritive quality of the menu items
●The choice of menu items that comprise a meal
●The amounts consumed
●The frequency with which the meals are eaten
Concerns
Nutrient content — Many fast foods can be high in energy, total and saturated fat, added sugar, cholesterol, and sodium and low in vitamins A and C, folic acid, fiber, and calcium [15,43,63-66]. This nutrient profile is evident in traditional fast food meals such as a hamburger, french fries, fruit turnover, and soft drink; or fried chicken, mashed potatoes with gravy, biscuit, and soft drink (table 1) [67]. Fat accounts for 45 to 55 percent of calories in some fast foods (as compared with recommended fat content of 30 percent or less of total calories). In a survey of fast food purchased at lunchtime from chain retailers in New York, only 1 in 36 meals purchased met the US Food and Drug Administration's guidelines for "healthy" sodium levels (600 mg/meal) and one in five meals exceeded the recommended daily limit for sodium (2300 mg) [68]. The average meal purchased contained 880 calories and 1750 mg sodium. In an analysis of 12 national fast food restaurants with over 5400 possible "kids' meal" combinations, less than 1 percent met the Institute of Medicine recommended nutrition standards in regard to fat, sugar, sodium, and whole grains for elementary school meals [69,70].
However, the nutrient content of fast food selections varies across countries [71]. Differences in total sugar content per serving can be seen for hamburgers, desserts, sandwiches, prepackaged beverages, and frozen beverages. Thus, evaluation of the nutritional quality of fast foods may be locale-specific.
The findings from a national household survey among children highlight the nutritional effects of fast food consumption [72]. Compared with children who did not eat fast food on a given day, children who did eat fast food consumed:
●More total energy (2236 versus 2049 kcal/day)
●More total fat (84 versus 75 g/day)
●More total carbohydrates (303 versus 277 g/day)
●More added sugars (122 versus 94 g/day)
●More sugar-sweetened, carbonated beverages (471 versus 243 g/day)
●Less milk (236 versus 302 g/day)
●Less fiber (13.2 versus 14.3 g/day)
●Fewer fruits and non-starchy vegetables (103 versus 148 g/day)
Similar findings were noted in a longitudinal multicenter cohort study of female adolescents [63]. In this study, increased frequency of fast food consumption was associated with increased intake of energy and sodium and increased intake of total fat and saturated fat as a percentage of calories.
In a national study of adolescents, intake of milk, fruits, and vegetables were generally low and achievement of recommended intake was less likely in youth who consumed fast food [42]. No relationships were seen between fast food consumption and achievement of recommendations for grains, meats/beans, and oils. In this study, no association was seen between adolescents' weight status and level of fast food intake.
Portion size — In response to health authorities' call to reduce portion sizes, fast food outlets have changed the names for portion sizes for menu items and meals. For example, major fast food outlets have phased out "super-sized," "biggie-sized," and "jumbo-sized" items; food items and meals are now available in "small," "medium," and "large." However, at point of ordering, customers are encouraged to upgrade smaller menu items to larger sizes for a few cents more. Because of these marketing techniques, children and adolescents learn to equate "volume" with "value." In addition, most fast food outlets have "specialty burgers" available with one to four beef patties and additional bacon and cheese "extras." Energy, fat, and sodium consumption increases substantially with the number of "extras." The choice of "large-size" or "specialty burgers" can significantly increase the energy, fat, and sodium content of the meal. As an example, a large hamburger supplies 540 kcal and 28 g of fat, compared with 250 kcal and 8 g of fat in a regular hamburger (table 1) [67]. Similarly, a large-size order of french fries, large soft drink, and dessert can add up to an additional 1030 kcal. Such a meal can provide 1570 kcal and 62 g of fat, which is approximately 80 percent of total daily energy needs and 100 percent of daily fat needs for a 13-year-old child [73,74]. Thus, the high energy density of a fast food meal tends to encourage overconsumption [43,65]. Legislation to require labeling on menus describing calorie content at the point of purchase is in place in several states, and national legislation is in progress [75]. As of May 2018, restaurant chains with 20 or more locations in the United States were mandated to label their menus and menu boards with calorie information [76].
Customers who purchase fast food exhibit somewhat more restraint when the energy content is revealed. In a survey study of several fast food chains, customers purchased a mean of 827 calories per meal and 34 percent purchased more than 1000 calories per meal [77]. When calorie information was posted at the point of purchase at one fast food outlet, patrons who noticed the information purchased an average of 52 fewer calories than those who did not notice the information. Similarly, in another study, 106 adolescents were asked to order dinner from fast food menus and then order from fast food menus with calorie and fat information posted next to the menu items. Although the majority (70 percent) of the adolescents did not modify their food-ordering behavior, 30 percent reduced calorie- and/or fat-ordering behavior [78]. Parents of young children also tend to respond to nutritional information if it is provided on the menu. In a randomized trial, the energy content of the food ordered by parents for their three- to six-year-old children was reduced by an average of 100 kcals when nutrition information was provided on the menu [79]. A parent's selection of food for his or her child also correlates with the parent's interest in and perceived empowerment about nutrition decisions [80].
The social context of most fast food meals also encourages overconsumption: Many fast food meals are consumed while riding in the car or watching television. In this type of setting, children tend to overeat because their attention is distracted and they are less aware of satiety signals [13].
Association with obesity — Fast food consumption may be particularly problematic for overweight adolescents [81]. In one study of fast food consumption among lean (body mass index [BMI] ≤85th percentile for age and sex) and overweight (BMI >85th percentile but <98th percentile) adolescents, both groups were instructed to eat as much or as little as desired during a one-hour "extra-large" fast food meal [82]. In this setting, both groups ingested a large amount of energy (mean energy intake 1652 kcal, or 62 percent of estimated daily requirement). However, overweight adolescents consumed more energy (1860 versus 1458 kcal, or 66.5 versus 57 percent of estimated daily requirement). In addition, whereas lean adolescents had similar total energy intakes on days during which they did and did not consume fast food (2575 versus 2622 kcal), overweight adolescents had increased total energy intake on fast food days (2703 versus 2295). In another study, ready access to fast food outlets was independently associated with an increased odds of diagnosed childhood obesity [83]. More frequent fast food consumption was associated with higher BMI measures in children [34]. Another large study of public school children in New York City found that living close (less than 0.25 mile or one-half block) to fast food restaurants was associated with a higher risk of overweight or obesity compared with those living further away (3 percent difference) [84]. However, another study suggests that consumption of a Western diet is more strongly associated with obesity and poor dietary outcomes than consumption of fast food itself [85]. Other studies have suggested that the intake of fast food among children presenting for obesity treatment may not be associated with the degree of obesity at baseline or the degree of weight loss during treatment [30,86].
MORE NUTRITIOUS FAST FOOD CHOICES — A steady diet of fast foods that is haphazard and that contains too much fat; too many calories; and too little fiber, vitamins, and minerals can be unhealthy for children and adolescents [87]. However, an occasional fast food meal can fit into an otherwise well-balanced diet. It is important to look at the overall diet quality rather than focus on one food or one meal. Nutritional excesses or deficiencies should be compensated for at other meals [62].
General suggestions — Adolescents in focus groups report that the main barriers to making healthy nutritional choices are taste preferences for less healthy foods and a lack of concern about personal health [88]. Although eating out in fast food restaurants is a fact of life for many American families, clinicians and parents can be powerful role models for their children and can teach them how to choose fast foods wisely [88-90]. The following represent general recommendations:
●Fill in "nutrient gaps" from a typical fast food meal by healthy snacks at home. Offer fresh fruits, vegetables, cheese and crackers, low-fat milk, calcium-fortified juices, and frozen yogurt as snacks. Making healthful foods taste better, look better, and be more convenient is also important [88].
●Encourage portion control; educate adolescents that anything that equates with bigness such as "large," "extra," "double," or "triple" will be high in calories and fat. Recommend smaller portions, since a regular serving is enough for most children, or sharing with a parent or sibling.
●Opt for whole-grain foods, fruits, vegetables, and calcium-rich foods.
●Enjoy eating out, be adventurous, and visit a variety of types of ethnic fast food restaurants. Try Mexican, Asian, Italian, and seafood restaurants as well as those serving American fare. As with eating at home, variety is the key to a well-balanced diet [67].
●When planning a fast food meal, try to choose an establishment that promotes healthier options at the point of purchase. This practice encourages some restraint and may help children learn how to make healthier purchases. (See 'Portion size' above.)
●Aim to remove the focus on individual foods as "good" or "bad." Instead, provide information on how to evaluate the nutrient density of a food item. It is the total dietary intake that contributes to a healthy eating plan [91,92].
Specific suggestions — By selecting foods that are naturally nutrient dense (lower in fat content and higher in vitamins, minerals, and fiber) and a cooking method that does not add a large amount of fat, well-balanced meals are available in an increasing number of fast food establishments (table 1) [13,93]. Because children and adolescents tend to underestimate calorie content of their fast food choices, it may be helpful to choose fast food establishments that post calorie information prominently at the point of purchase to encourage restraint and informed purchasing by customers [77,94,95]. Unfortunately, although restaurant menu-labeling increased parents’ nutrition information awareness, it did not decrease calories purchased by children or parents [96,97].
The following specific suggestions can be used to improve the nutritional quality of meals at fast food establishments:
●Sandwiches
•Request single-patty hamburgers and grilled, charbroiled chicken (rather than breaded and deep-fried). For deli sandwiches, select lean turkey or roast beef, which provide less than 30 percent of their energy from fat. These meats are good sources of iron and zinc.
•Limit toppings such as cheese, bacon, and mayonnaise. Mayonnaise can add approximately 80 calories (9 g of fat). Deli sandwiches made of lean turkey or roast beef (mustard only) provide less than 30 percent of their energy from fat. Low-fat extras such as lettuce, tomato, onions, mustard, and low-fat salad dressings make healthy sandwich toppings.
•Select whole-wheat buns when possible to provide B vitamins and fiber.
●Alternative main dishes
•Try chili or soft tacos. Soft tacos have less fat than hard tacos because the tortilla has not been fried. Chili is a good source of fiber, zinc, folic acid, and iron.
•Use salsa to add extra flavor; limit the use of high-fat sour cream and guacamole.
●Side dishes
•Choose a baked potato rather than french fries, but limit the use of butter, sour cream, bacon bits, and shredded cheese. Baked potatoes provide vitamin C and fiber. Vegetables or chili are healthy choices for toppings. If available, separate side dishes of steamed vegetables or fruit supply vitamins A and C and fiber.
●Pizza
•Order thin-crust pizzas made with whole wheat, low-fat cheese, and vegetables or lower-fat meat, such as ham or chicken. Higher-fat sausage or pepperoni should be avoided.
•Even with these adjustments, pizza is often a source of excessive calories. Check the calorie content of the pizza and adjust intake accordingly.
●Salad
•Avoid large amounts of high-fat items, such as regular fat-containing dressing, bacon bits, and shredded cheese.
•Assorted fresh fruits and vegetables or beans add extra fiber, vitamins, and minerals.
●Beverages
•Water (plain or sparkling) is a healthy option, particularly for adolescents who are overweight.
•Choose low-fat milk or yogurt shakes as substitutes for soft drinks. These dairy foods provide calcium and vitamin D.
•Fruit juice provides folic acid and vitamin C, but intake should be limited (eg, one or fewer servings daily) because it also has high sugar and energy content.
●Desserts – Select low-fat frozen yogurt cones or sundaes and fresh fruit [98]. Avoid fried pies, ice cream, and cookies.
INFORMATION RESOURCES — It is possible to teach children and adolescents how to evaluate healthy food choices by allowing them to "order" from the menus of their favorite fast food restaurants on the internet. It is important to compare the fast food choices not only with other fast food options but also with dietary recommendations for children, especially for energy intake (table 2A-B).
●The MyPlate website, from the United States Department of Agriculture, is an interactive tool that presents guidelines for healthy eating, which are also summarized in a separate UpToDate topic review. (See "Dietary history and recommended dietary intake in children", section on 'Terminology for dietary standards'.)
●The website HealthyDiningFinder is a resource of healthier menu selections from 50,000 nationwide restaurants. These selections emphasize lean protein, fruits, vegetables, and whole grains. Featured menu items must meet specific nutrient criteria for calories, fat, and saturated fat. To be included, entrees must have the following characteristics:
•Lean meats, fruits and/or vegetables, and 100 percent whole wheat.
•No more than 750 calories, 25 g fat, 8 g saturated fat. Side dishes, appetizers, and desserts must contain no more than 250 calories, 8 g fat, and 3 g saturated fat. Foods lower in sodium and cholesterol also are featured.
●The website Fast Food Nutrition provides a list of typical food selections from many of the common fast food restaurants. Each food selection contains tables that show the relative amounts of dietary energy and fat, the proportion of calories from fat in the particular item selected, or a comparison of several food items. In addition, many fast food restaurants provide nutrition information pamphlets upon request. In this way, fast foods are not necessarily seen as forbidden foods but, rather, some of the menu items are better choices to make.
SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Healthy diet in children and adolescents".)
SUMMARY
●General health implications – Frequent consumption of fast food has adverse effects on nutrition because of excessive content of energy and fat and low nutritional value (table 1). Moreover, consumption of fast food is associated with other poor nutritional habits. (See 'Introduction' above.)
●Specific nutritional concerns – Common nutritional hazards of many fast foods are that they provide excessive energy (calories), total and saturated fat, cholesterol, and sodium and are low in vitamins A and C, folic acid, fiber, and calcium. In addition, portion sizes for many fast foods are in excess of typical caloric needs for most individuals, and marketing techniques further promote excessive consumption by equating "volume" with "value." (See 'Nutrient content' above and 'Portion size' above.)
●Goals of counseling – Because fast food is widespread in the United States and many other countries, eliminating fast food consumption entirely is not a realistic goal for many families. Instead, the clinician should focus on reduction in fast food intake by providing nutritional education and suggesting healthier alternatives to the individual patient (table 1). (See 'Introduction' above and 'More nutritious fast food choices' above.)
●Counseling to improve fast food choices – Many fast food establishments now offer some items with improved nutritional value, in addition to traditional selections. By selecting foods that are lower in fat content and higher in vitamins, minerals, and fiber, well-balanced meals are available in an increasing number of fast food establishments. (See 'More nutritious fast food choices' above.)
●Information resources – The clinician should provide general guidance to help their patients reduce the frequency and improve the nutritional value of their fast food consumption. In addition, detailed nutritional information about fast food is available through the internet, and the clinician can use these sites to review and discuss the patient's usual fast food choices. It is important to compare the fast food choices not only with other fast food options but also with dietary recommendations for children, especially for energy intake (table 2A-B). (See 'Information resources' above.)
