Healthy eating for adolescents

INTRODUCTION — 

Adolescence is a nutritionally vulnerable life phase. Poor eating habits formed during adolescence can lead to obesity and diet-related diseases in later years. In addition, the high incidence of unhealthy behaviors by adolescents can contribute to nutritional inadequacies, mental health problems, and development of eating disorders. Primary care clinicians are in an optimal position to screen for nutritional deficiencies and disordered eating patterns, provide counseling to the adolescent patient and caregivers, and refer to a dietitian if needed.

This topic review discusses goals for nutrition in adolescents, characteristic challenges for adolescent eating habits (including skipping meals, fast food consumption, frequent snacking, and dietary restriction behaviors), and recommendations for interventions to improve nutrition. The nutritional requirements for adolescents and specific eating disorders are discussed separately. (See "Estimation of dietary energy requirements in children and adolescents" and "Eating disorders: Overview of epidemiology, clinical features, and diagnosis".)

GOALS FOR NUTRITION IN ADOLESCENTS — 

The overall goal for nutrition in adolescents is to promote regular, well-balanced meals and snacks.

Sound nutrition is particularly important during adolescence because of the increased nutritional needs during this life phase as a result of the rapid growth and changes in body composition associated with puberty [1]. Moreover, establishing and maintaining healthy eating behaviors can play a role in the prevention of several chronic diseases, including obesity, coronary heart disease, certain types of cancer, stroke, and type 2 diabetes [2-6]. For this reason, nutrition remains an important objective for the "Healthy People 2030" campaign [7]. (See "Healthy diet in adults".)

However, optimizing nutrition can also be challenging during adolescence because of the associated social and developmental changes that may affect adolescents' food choices and nutrient intake, such as the quest for independence and acceptance by peers, preoccupation with self-image, increased activity levels, greater time spent at school and/or work activities, and irregular sleeping patterns [8-10]. With more independency, adolescents increasingly make their own decisions about what, when, where, and with whom to eat [11]. Thus, this is an important time to monitor nutrition and eating patterns and provide counseling as needed. (See 'Challenges for adolescents' below.)

Eating patterns — Adolescents should eat three meals a day, usually with healthy snacks in between.

Eating meals consistently (eg, not skipping meals) is associated with lower rates of overweight or obesity, especially among boys, according to a meta-analysis of studies of adolescents in resource-abundant settings [12]. Healthy snacks can help meet the increased energy and nutrient needs of adolescence. Snacks that are nutrient dense (ie, snacks that provide recommended nutrients, rather than snacks that provide calories without additional nutritional benefit) can help to fill the "nutritional gaps" (eg, fiber, vitamin A, calcium, iron) that remain after traditional meals.

Meals eaten with family are associated with higher diet quality [13-18]. One large study in children aged 9 to 14 years demonstrated that those who ate meals with their families most or all of the time had healthier diets than those who did so rarely or never [19].

Nutrient content — In the United States, the recommended diet composition is based on the Dietary Guidelines for Americans [20] and can be taught by the United States Department of Agriculture MyPlate tool [21]. The tool was developed to individualize dietary guidelines according to age, sex, and activity level. The plate provides a visual tool for dietary balance. MyPlate focuses on five food groups (fruits, vegetables, grains, dairy, and protein); individuals are encouraged to cover one-half of their plate with fruits and vegetables. By contrast, the previously used pyramid-based teaching tool had six food groups and included a category for "discretionary calories." Although the teaching tool is organized by food groups, it is also designed to provide macronutrient balance, meeting targets for protein (10 to 30 percent of total daily calories), carbohydrates (45 to 65 percent of total daily calories), and fat (25 to 35 percent of total daily calories) [20].

Adolescents who follow a diet with limited dairy or calorie intake warrant evaluation and counseling to ensure sufficient intake of protein and other nutrients. For those following a vegetarian diet, the main focus is to ensure adequate protein intake and quality, which can often be provided by dairy products in addition to plant proteins. Those following a vegan diet require a vitamin B12 supplement, in addition to adequate intake of varied plant proteins. (See "Vegetarian diets for children", section on 'Protein'.)

Examples of recommendations for individuals at several different calorie levels are provided in the tables (table 1 and table 2). (See "Dietary history and recommended dietary intake in children" and "Estimation of dietary energy requirements in children and adolescents".)

Key components of these nutritional requirements are [20]:

●Vegetables and fruits – For an adolescent with low activity levels, the dietary recommendations translate to approximately 2.5 cups of vegetables and 1.5 cups of fruit daily for girls (for those with daily intake of approximately 1800 calories) and 3 cups of vegetables and 2 cups of fruit daily for boys (for those with daily intake of approximately 2200 calories) (table 1). For lettuce and other raw leafy greens, a serving is twice as large (1 cup of lettuce = 1/2 cup of other vegetables).

●Dairy – The dietary guidelines outlined in MyPlate promote a high intake of dairy products (approximately three to four servings/day for adolescents); low-fat or fat-free products are recommended [21]. Dairy products are rich in calcium. In the United States, they are also fortified with vitamin D. Both of these nutrients are sparse in most other foods and beverages.

Adolescents who do not consume this amount of dairy products will need to consume substantial amounts of other foods that are rich in calcium and vitamin D (table 3) and/or take supplements to meet their requirements for these nutrients. Plant-based milks can be appropriate substitutes. Because the nutrient content of these products varies substantially, advise the patient to choose a brand that is "enriched" and contains approximately 100 international units (2.5 micrograms) of vitamin D and 300 mg of calcium per 8 ounce serving. Compared with cow's milk, calcium-fortified orange juice provides similar amounts of vitamin D and calcium but also high quantities of sugar and minimal protein.

●Calcium – The recommended dietary allowance (RDA) for calcium is 1300 mg for males and females 9 to 18 years of age [20]. The recommended three to four servings/day of dairy products provides 900 to 1200 mg of calcium, but many adolescents fail to meet this goal. Calcium intake can be increased through foods that are naturally rich in calcium, calcium-fortified foods, and calcium supplements (table 3). (See "Bone health and calcium requirements in adolescents", section on 'Calcium intake'.)

●Vitamin D – The RDA for vitamin D is 600 international units (15 micrograms) daily. Some individuals appear to require higher vitamin D intake to maintain serum concentrations of 25-hydroxyvitamin D (25-OHD) in the target range. (See "Vitamin D insufficiency and deficiency in children and adolescents", section on 'Prevention in older children and adolescents'.)

The recommended three servings of fortified dairy products (or fortified plant-based beverage) provide approximately 300 to 350 international units of vitamin D [22], which is approximately one-half of the recommended daily intake for adolescents. Thus, intake of vitamin D-fortified foods (breads, cereals, and juices) and fatty fish (salmon, mackerel, and sardines) and supplementation of vitamin D may be needed, particularly for adolescents who have less than the recommended three servings of dairy products daily or those with low serum concentrations of 25-OHD.

In the United States, approximately 15 percent of adolescents have vitamin D deficiency or insufficiency (defined in these studies as serum 25-OHD concentrations <20 ng/mL [50 nmol/L]). However, the prevalence varies considerably among different countries and subpopulations because of differences in risk factors, including diet, skin pigmentation, sun exposure, and obesity. (See "Vitamin D insufficiency and deficiency in children and adolescents", section on 'Prevalence'.)

●Iron – For children age 9 to 13, the RDA for iron is 8 mg daily [20]. For adolescents 14 to 18 years old, the RDAs are 11 mg daily for males and 15 mg daily for females. Good food sources of iron are outlined in the table (table 4). Some adolescents may require iron supplements. (See "Iron requirements and iron deficiency in adolescents".)

●Protein – The RDA for protein is approximately 35 to 45 g/day for adolescent girls and 35 to 50 g/day for adolescent boys [20,23]. This RDA refers to the protein component and not to the weight of the whole food (meat, egg, etc).

Adolescents who eat meat usually consume sufficient amounts of protein, unless they are experiencing food insecurity or follow a restrictive diet. For meat, poultry, or fish, 5 to 6.5 ounces (140 to 185 grams) fulfills the protein requirement for females and 5.5 to 7 ounces (155 to 200 grams) fulfills the requirement for males. For other protein foods, the ounce equivalents are shown in these protein foods tables from the MyPlate website [21].

Attitudes toward food and body image — Clinicians can support a healthy attitude toward eating by emphasizing the importance of healthy nutrition for long-term physical and mental health, regardless of body shape, weight, or body mass index. They should encourage patients to attend to internal hunger and fullness signals, while recognizing that some adolescents may struggle with this goal because of their food preferences and choices, mental health, and other stressors. Clinicians should explore patient attitudes toward their bodies, attempts to alter body shape or weight, and negative experiences that patients may have encountered related to body shape. (See 'Attitudes toward food and body image' below.)

CHALLENGES FOR ADOLESCENTS — 

A multitude of biopsychosocial factors contribute to the erratic and unhealthy eating behaviors that are common during adolescence [8,10,24-26]. In addition, adolescents may have beliefs about their cultural foods and eating habits, often reflecting their family's notions of healthy and unhealthy foods, which may or may not be accurate [27]. Unhealthy eating habits are seen in adolescents in the United States and many other countries [28-32].

More than two-thirds of adolescents (especially boys, those from rural environments, and those who are overweight) have unsatisfactory knowledge about dietary recommendations, sources of nutrients, diet-disease relationships, and dietary habits [33]. In this group, television is the main source of information about nutrition for adolescents. Media food marketing has a small but significant effect on unhealthy eating behaviors in preadolescents and adolescents [34].

As for any age group, food insecurity can contribute to unhealthy food choices, including among individuals with obesity. Screening for food insecurity is an important step in any form of nutritional evaluation and counseling; brief screening questions are outlined separately. (See "Indications for nutritional assessment in childhood", section on 'Food insecurity'.)

Eating patterns — Common eating patterns that can interfere with a healthy diet are described here, with potential solutions below. (See 'Eating patterns' below.)

Skipping meals — Adolescents may skip meals because of irregular schedules [35], altered circadian patterns, food insecurity, or efforts to lose weight.

●Prevalence – Breakfast and lunch are the meals most often missed, but social, school, and work activities can cause evening meals to be missed as well [36-39].

In North America, 12 to 50 percent of adolescents skip breakfast on any given day; older adolescents (those age 15 to 18 years) are twice as likely to skip breakfast as are younger adolescents, and girls are more likely to do so than boys (35 versus 25 percent in one study) [8,38,40-45]. Reasons for skipping breakfast include lack of time, early school activities, proximity of fast food outlets and grocery stores near schools [29], or poor appetite first thing in the morning [46].

●Effects on diet quality – The omission of breakfast can affect school performance and the overall quality of the diet [47-51]. In one cross-sectional and longitudinal study of school breakfast programs, students with greater participation in the breakfast program had greater increases in math grades, decreases in child and teacher ratings of psychosocial problems, and decreases in absence and tardiness than did children with less participation [52].

Total nutrient intakes are lower among adolescents who skip breakfast compared with those who consume breakfast [28,47,50,53]. Adolescents who consume breakfast have healthier overall eating habits and a higher intake of calories and several other nutrients (fiber; iron; calcium; and vitamins A, B6, and B12) [41,48,54,55]. Common sources of these nutrients in breakfast foods include fortified ready-to-eat cereals, milk, and fruits. Adolescents who skip breakfast tend not to compensate for the missed micronutrients at other meals.

●Effects on body weight – Adolescents, particularly females, may use skipping meals as a strategy for weight control [56]. However, meal skipping for weight control may result in an unhealthy diet and may be associated with unintended weight gain during adolescence. Indeed, multiple studies have documented an association (not necessarily causal) between skipping meals and weight gain [36,53,57,58]. (See 'Pathologic dietary restriction ("dieting") and body image' below.)

Possible explanations for the association between meal skipping and weight gain include [58]:

•Adolescents perceive that they are reducing energy intake by skipping meals, when in fact they often are not. The calories that are "saved" by skipping meals are often made up through heavy snacking on nutrient-poor foods or by overeating at the next meal [57,59].

•Individuals with a propensity to gain weight are more likely to skip meals to compensate.

•Skipping meals is a marker for other poor nutrition and physical activity habits [60,61].

•Skipping meals is associated with circadian disturbances that promote weight gain [57,62,63].

Snacking — Most adolescents snack. Teenagers seldom conform to a regular pattern of three meals per day; more than one-half report eating at least five times per day [64,65]. Snacks are a major source of energy and nutrients, providing nearly one-quarter to one-third of total energy intake for many adolescents [66,67].

Depending on their timing and composition, between-meal snacks can contribute in negative or positive ways to the adolescent diet [68]. Poorly timed snacks that are high in calories and low in nutrients (ie, "junk food") may blunt the adolescent's mealtime appetite and replace nutritious foods that are needed for growth and development.

Distracted eating — Television viewing or other "screen time" is associated with increased snacking among children and adolescents and also with obesity [69-71]. As an example, spending more than 120 minutes watching television is associated with significantly higher intakes of total fat and polyunsaturated fat and lower intake of several minerals and vitamins [72]. Adolescents with high media exposure, including television and video and computer games, are more likely to drink sugar-sweetened beverages rather than water or milk [73]. Exposure to advertising of poor-quality snack foods appears to be an important mechanism for the association between television viewing and food intake or obesity. (See "Definition, epidemiology, and etiology of obesity in children and adolescents", section on 'Environmental factors'.)

Nutrient content — Common problems with dietary balance are described here, with potential solutions below. (See 'Nutrient content' below.)

Insufficient micronutrient intake — National and population-based surveys in the United States have found that adolescents often fail to meet dietary recommendations for overall nutritional status and for specific nutrient intakes [74-76]. Actual consumption of fruits and vegetables is well below the recommended targets [38,77,78]. Low consumption of fruits and vegetables is associated with higher intakes of fast food. (See 'Fast food' below.)

In particular, many adolescents receive a higher proportion of energy from fat and/or added sugar and have a lower intake of a vitamin A, folic acid, fiber, iron, calcium, vitamin D, and zinc than is recommended [20,79,80]. Iron deficiency is particularly common among adolescent females due to menstrual losses as well as inadequate iron intake; iron deficiency can impair cognitive function and physical performance. In addition, adolescent females often have inadequate calcium intake, which may increase fracture risk during adolescence and the risk of developing osteoporosis in later life. A substantial proportion of adolescents have vitamin D insufficiency or deficiency, although requirements depend on a variety of factors, including diet, skin pigmentation, sun exposure, and obesity. Adequate vitamin D is important for optimal bone mass accrual and low levels, independent of weight status, and is associated with cardiovascular risk factors such as hypertension, insulin resistance, dyslipidemia, and the metabolic syndrome [81-83].

Prevention, monitoring, and management of these nutrient deficiencies are discussed separately. (See "Iron requirements and iron deficiency in adolescents" and "Bone health and calcium requirements in adolescents" and "Vitamin D insufficiency and deficiency in children and adolescents".)

Foods with high caloric density and low nutritional density — A related problem is excessive reliance on foods with high fat and/or sugar content, which tend to have high caloric density and low nutritional density. Studies have highlighted the negative impact of these food types on brain function, resulting in cognitive impairment and altered reward processing, which may predispose individuals to dysregulated eating and impulsive behaviors [84]. Common categories are:

●Fast food – Fast foods are popular choices because they are flavorful, inexpensive, familiar, and available at almost any hour of the day or night and because many adolescents socialize with their peers at fast food establishments [85-88]. Consumption of fast food is promoted by extensive advertising campaigns, including on social media [89-94].

In the United States, approximately 36 percent of children and adolescents consume fast food on a typical day, which provides, on average, approximately 14 percent of daily calories. Fast food intake tends to increase with age [94,95].

Fast food generally has adverse effects on diet quality, although the effect depends on the frequency and food choices [94,96,97]. Traditional fast foods are low in iron, calcium, vitamins A and C, fiber, and folic acid and high in energy, sodium, cholesterol, and total and saturated fat (table 5) [98-100]. Fat provides more than 50 percent of the calories in many fast food items. In Project Eat (Eating Among Teens), the total energy intake of adolescents who reported eating at a fast food restaurant more than three times in the preceding week was almost 40 percent higher than that of who did not [86]. Studies vary in their conclusions about whether fast food consumption is associated with overweight status [101-104].

●Processed foods – One study using data from the National Health and Nutrition Examination Survey found that American adolescents consumed approximately two-thirds of their caloric intake from highly processed foods, such as chips, cookies, candy, soft drinks, and ready-to-eat products (such as pizza, instant soup, hot dogs, and chicken nuggets) [105]. Moreover, highly processed food intake was inversely associated with metrics of cardiovascular health, based on a composite score of excess body weight, smoking, physical activity, blood pressure, cholesterol, and dysglycemia. This is consistent with studies in adults, which link consumption of highly processed foods to risks for cardiovascular disease and type 2 diabetes [106]. (See "Healthy diet in adults", section on 'Highly processed foods'.)

●Sugar-sweetened beverages – Sugar-sweetened beverages often have a negative impact on diet quality [79] and also contribute to weight gain [107]. In a national survey in the United States, sugar-sweetened beverages comprised 7 percent of the calories consumed by children and adolescents [108]. Increased intake of sugar-sweetened beverages also may be an important predictor of cardiometabolic risk independent of weight status [109]. Moreover, dietary sodium is associated with higher intake of sugar-sweetened beverages, identifying a possible link between dietary sodium and excess energy intake [110].

Pathologic dietary restriction ("dieting") and body image — It is common for adolescents to be unhappy with and self-conscious about their changing bodies [111]. In many cultures, thinness, no matter how unrealistic, is perceived as the desired body shape, particularly for females. The observations that adolescents often perceive themselves to be overweight even when they are not have been shown in a large population study [112].

These body image considerations often lead to pathologic dietary restriction ("dieting") behaviors, ie, the manipulation of food intake and food choices that are specifically driven by weight concerns rather than health concerns. This type of dieting is distinct from efforts to adopt healthy eating and other lifestyle behaviors (ie, physical exercise) that are recommended to optimize nutrition and body weight as part of long-term health goals. Monitoring for these behaviors and counseling to support a healthy body image are discussed below. (See 'Attitudes toward food and body image' below.)

●Motivations – Adolescents report the following reasons for dieting [113-117]:

•Feeling "too fat"

•Teasing by peers

•Pressure from family members

•Advice of a coach or sports instructor

•Wanting to look better (ie, thin)

•Desire to improve health

In addition, social media influencers often promote unrealistic beauty and body standards [118].

●Associated eating patterns – Most adolescents diet mainly by restricting food, either by excluding foods or entire food groups that are perceived as "fattening" (eg, meats, eggs, milk and dairy products) and/or by skipping meals [119,120] (see 'Skipping meals' above). In a survey of adolescents in the United States, the most common weight loss behaviors included [112]:

•Exercising (84 percent)

•Drinking a lot of water (52 percent)

•Eating less "junk" foods or fast foods (45 percent)

•Increasing intake of fruits, vegetables, and salads (45 percent)

While these behaviors ostensibly fit with goals for improved nutrition, at the extremes, they may have negative effects, leading to disordered eating and often not contributing to significant weight loss for those with overweight/obesity. (See "Eating disorders: Overview of epidemiology, clinical features, and diagnosis" and "Prevention and management of childhood obesity in the primary care setting".)

●Prevalence – A history of dieting can be obtained in approximately 40 to 70 percent of adolescents [121-123]. More females than males diet (45 versus 20 percent in one study) [112,115], and the sex difference increases significantly with age (56 percent of girls in grades 9 through 12 versus 36 percent of girls in grades 5 to 8) [115,122,124,125]. Weight concerns and dieting are so common among female adolescents that they are considered to be normative [111,126].

The frequency of dieting varies by region and by nation. In a 2001/2002 World Health Organization report of students aged 11, 13, and 15 years in 35 countries and regions in Europe and North America, dieting was most common among adolescents in Hungary, the United States, Denmark, Canada, and Israel [122].

●Adverse effects on nutrition – Dieting behaviors can compromise intake of energy and nutrients that are essential for adolescents' growth and development. In some cases, the result is a diet that is low in several major nutrients that are already marginal in many adolescents' diets (eg, iron, calcium, zinc), although results vary by weight status, sex, and survey method [119,120,127].

An example of nutrient deficits related to dieting comes from a study of 16- to 17-year-old English girls, comparing those who dieted with those who did not [128]. The mean energy intake of the dieters was less than that of the nondieters (1604 versus 2460 kcal/day). Dieters had significantly lower intakes of breakfast cereal, milk, meat, and meat products. Twice as many dieters as nondieters failed to achieve recommended levels (dietary reference values for United Kingdom) for calcium, zinc, and selenium, likely due to lower intake of fortified foods.

●Adverse effects on health – Long-term dieting may have adverse effects on an adolescent's health [129]. Potential adverse effects include irritability, anxiety, mood disorders, difficulty concentrating, sleep disturbance, muscle wasting, cardiac dysfunction, digestive tract disorders, menstrual irregularity, interruption in growth, delayed sexual maturation, and inadequate bone mass accumulation [114,121,130,131].

Adolescents who diet frequently are at increased risk for developing eating disorders such as anorexia nervosa and bulimia [114,132]. As an example, a longitudinal study of 2500 adolescents found that adolescent girls who dieted were at twice the risk for engaging in extreme weight-control behaviors (including vomiting or laxative use) and reporting an eating disorder five years later compared with nondieters [133]. (See "Eating disorders: Overview of epidemiology, clinical features, and diagnosis".)

●Lack of weight control – Many dieting behaviors used by adolescents in an attempt to lose weight may be ineffective in reducing weight [36,53,57,58]. Paradoxically, these behaviors are associated with weight gain, perhaps mediated by compensatory eating, binge-eating behaviors, or circadian disturbances [58,60,61,114,134-136]. In addition, repeated dieting is correlated with cycles of weight loss and gain (ie, "yo-yo" dieting), a risk factor for development of coronary heart disease [137,138]. (See "Overview of established risk factors for cardiovascular disease", section on 'Obesity'.)

STRATEGIES TO PROMOTE COMPLETE, WELL-BALANCED NUTRITION

General strategies — The primary care clinician or dietitian can promote healthy nutrition with these steps:

●Ask about eating patterns and food preferences during routine visits, with more detailed follow-up and/or referrals if concerns are identified.

●Screen families for food insecurity. (See "Screening tests in children and adolescents", section on 'Screening for poverty'.)

●Routinely counsel about healthy eating patterns and food selections, prioritizing the more common issues, as outlined below.

●Explore and debunk some common questions and myths about food (table 6).

●Engage both the adolescent and parents or caregivers in the counseling when possible. Including the parents and caregivers can be helpful because they have the opportunity to influence their child's dietary intake in a variety of ways, the most important of which are the decisions made about what foods are available within their home [139]. In addition, the clinician can help shape the caregiver's parenting style to be most productive: An authoritative parenting style (in which a parent helps their child learn through reasoning) tends to promote healthy nutrition compared with authoritarian (in which a parent expects obedience and uses criticism or punishment to influence their child) or permissive parenting styles. In certain parent-adolescent relationships, counseling the adolescent separately may be more productive.

Nutrition education interventions focusing on spices and herbs also may be an effective tool to improve diet quality and healthy eating attitudes, especially among adolescents living in urban settings [140]. The addition of spices and herbs was associated with modest improvement in the consumption of grain and protein food products, as well as attitudes toward eating vegetables, whole grains, lean protein, and low-fat dairy products.

Eating patterns — Counseling to promote healthy eating patterns includes:

●Avoid skipping meals – Advise adolescents not to skip meals, particularly breakfast. Explain that skipping meals does not help with weight control and indeed may promote weight gain. Moreover, eating regular meals can increase total nutrient intake as well as the mean number and amount of servings from food groups that typically are low in adolescents' diets (eg, iron- and calcium-rich foods, fruits, and vegetables). (See 'Skipping meals' above.)

●Encourage family-based meals – The frequency of having meals with the family decreases during adolescence, and family meals are associated with higher diet quality [13-18]. One large study in children aged 9 to 14 years demonstrated that those who ate meals with their families most or all of the time have healthier diets than do those who do so rarely or never [19].

●Healthy snacking – Snacks can contribute to healthy nutrition and may be particularly important for adolescents who are very active and/or during growth spurts. However, it is important to choose healthy foods for snacks. This can be challenging because many common snack foods are high in sugar and fats, with low nutritional value.

●Balance and moderation – Encourage patients to choose well-balanced nutrition without recommending complete elimination or limitation of certain foods or food groups from their diet. Rather, educate patients about which foods have lower nutritional value and encourage them to consume these foods less frequently or in smaller quantities.

Nutrient content

Food group balance and goals — Provide resources for reliable information about nutrition. One option is the interactive MyPlate tool. The clinician can introduce the website during a counseling session and demonstrate how to use the MyPlate Plan to help the teen find the individualized nutritional goals appropriate for their age, sex, and level of activity. Approximate servings of each food group for different caloric intakes are outlined in the table (table 1), and beverage recommendations are in the figure (figure 1).

Key nutrients to emphasize are iron (table 4), calcium (table 3), and vitamin D. (See 'Nutrient content' above.)

Snacking — Teach adolescents how to improve the overall quality of their diets with nutritious snacks. Instead of selecting high-fat, high-sugar, nutrient-poor snacks (such as candy, pie, cakes, cookies, and chips), adolescents should select foods that are lower in fat and more nutrient dense, such as:

●Fresh fruit or vegetables with low-fat yogurt dip

●Iron-fortified cereal and low-fat milk

●String cheese

●Cheese and crackers

●Low-fat frozen yogurt

●Calcium-fortified cereal bars and juices

Fast food — Fast foods are a way of life for many adolescents, and eliminating fast food consumption entirely is not a realistic goal for many families. Instead, the clinician should focus on reducing fast food intake by providing nutritional education and suggesting healthier alternatives to the individual patient. Despite the suboptimal nutrition content in many fast food offerings, an occasional fast food meal can fit into an otherwise well-balanced diet.

Teach adolescents how to make wise food choices at fast food restaurants. One counseling approach is to allow the teen to "order" from the menus of their favorite fast food restaurants on the internet. Another approach is to counsel on the portion sizes of food items when eating outside of the home to encourage the adolescent to choose smaller portion sizes. 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 2 and table 1).

The Fast Food Nutrition website 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.

Many fast food restaurants offer lower-fat and nutrient-dense food choices in addition to traditional selections, and it is possible to order a relatively healthy meal [141,142]. As examples:

●Healthier choices include salad bars, baked potatoes, steamed vegetables, low-fat frozen yogurt, and lower-fat sandwiches (table 5).

●Limit toppings such as cheese, bacon, sour cream, and mayonnaise.

●Encourage portion control by educating adolescents that anything that equates with bigness such as "large," "extra," "double," or "triple" will be high in calories and fat.

●For beverages, choose water or low-fat milk (ideally unflavored) rather than soft drinks (figure 1). For adolescents who are trying to limit caloric intake, choosing an artificially sweetened beverage is a reasonable strategy to reduce the use of sugar-sweetened beverages. (See "Overview of nonnutritive sweeteners".)

In addition, adolescents can balance the nutritional deficits in fast food by including nutritious snacks in their diet, including fresh fruits and vegetables, low-fat milk, and yogurt. It is the total dietary intake that contributes to a healthy eating plan [143]. (See 'Snacking' above.)

Attitudes toward food and body image

●Monitoring – Health care professionals play a role in educating adolescents about the normal changes in growth and development that occur during adolescence. As part of the routine health maintenance examination, primary care clinicians should ask about body image and dieting patterns and/or use a screening tool to identify disordered eating patterns [114,144].

If the adolescent is using unhealthy dieting behaviors but has no clear symptoms of an eating disorder or significant weight loss, counseling or referral to a dietitian may be sufficient, with close monitoring [114,145]. If an eating disorder is suspected (if weight loss persists or outpatient management for weight gain fails), referral to a multidisciplinary team or professional with expertise in eating disorders is indicated. (See "Eating disorders: Overview of epidemiology, clinical features, and diagnosis", section on 'Screening' and "Eating disorders: Overview of prevention and treatment".)

●Counseling – Key points for counseling include:

•"Dieting" (eg, skipping meals, very restrictive eating) is neither healthy nor desirable for growing bodies and may actually increase body weight.

•No one body type is ideal, and adolescents' bodies develop at different rates; body diversity is natural and healthy.

•To model healthy attitudes toward food, avoid categorizing foods with binary language (eg, "good," "bad," "safe," "fattening"). In addition, focus discussions on positive aspects, such as which foods are healthy and recommended (rather than on foods to avoid).

•The goal of nutritious eating is promotion of long-term health and well-being, and this should be the focus of messaging to patients and their families.

•Counsel family members about these same concepts and, particularly, that they should avoid criticizing the adolescent about their eating habits or body weight.

Strategies for counseling about weight concerns while also promoting a healthy body image are summarized in the table (table 7) and discussed in more detail separately. (See "Prevention and management of childhood obesity in the primary care setting", section on 'Strategies for counseling about weight management'.)

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 AND RECOMMENDATIONS

●Challenges for adolescents – Adolescence is a nutritionally vulnerable time period. Common dietary habits include skipping meals, frequent snacking, consumption of fast foods, dietary imbalance (leading to nutritional deficiencies), restrictive dieting, and disordered eating. (See 'Challenges for adolescents' above.)

Primary care clinicians are in an optimal position to provide nutritional screening, counseling, and referral to a dietitian or other specialist if needed. The following general approaches are useful for counseling.

●Eating patterns – Encourage adolescents to eat all meals, particularly breakfast. Advise them that skipping meals does not help with weight control and indeed may promote weight gain. Promote healthy (nutrient-dense) snacks, while avoiding poorly timed snacks that are high in calories and low in nutrients (ie, "junk food"), which can blunt the adolescent's mealtime appetite and replace nutritious foods. (See 'Eating patterns' above.)

●Dietary balance – The MyPlate website is a useful tool to support education about a healthy diet and to emphasize variety for supplying all of the necessary nutrients for growth and development. Examples of servings of each food group for different caloric intakes are outlined in the table (table 1), and beverage recommendations are in the figure (figure 1).

•Recommend reduced-fat dairy and animal products, moderate portion sizes, and less frequent consumption of higher-fat items. Along with increased intake of fruits, vegetables, and whole grains, this suggestion can help adolescents achieve appropriate targets for energy, vitamin, and mineral intakes. (See 'Food group balance and goals' above.)

•Adolescent females are at risk for iron deficiency due to menstrual losses; advise them to consume iron-rich animal foods (meats) or ample foods with nonheme iron (table 4). Some adolescents may require iron supplements. (See "Iron requirements and iron deficiency in adolescents".)

•Educate adolescents, particularly females, about the importance of calcium to bone health and strategies for ensuring adequate calcium intake (table 3). (See "Bone health and calcium requirements in adolescents".)

●Fast foods and snacking – Eliminating fast food consumption entirely is often not realistic. Instead, focus on reducing fast food intake by providing nutritional education and suggesting healthier alternatives to the individual patient (table 5). The Fast Food Nutrition website provides a list of typical food selections from many of the common fast food restaurants. (See 'Fast food' above.)

●Body image and dieting – Educate adolescents that "dieting" (the manipulation of food intake and food choices driven by weight concerns rather than health goals) is not healthy. Efforts at weight reduction can compromise nutrition, growth, and health and can increase the risk for the development of an eating disorder. Moreover, dieting behaviors are often associated with weight gain. (See 'Pathologic dietary restriction ("dieting") and body image' above and 'Attitudes toward food and body image' above.)

Key points for counseling include:

•Dieting (eg, skipping meals, very restrictive eating) is neither healthy nor desirable for growing bodies and may actually increase body weight.

•No one body type is ideal, and adolescents' bodies develop at different rates; body diversity is natural and healthy.

•To model healthy attitudes toward food, avoid categorizing foods with binary language (eg, "good," "bad," "safe," "fattening"). In addition, focus discussions on positive aspects, such as which foods are healthy and recommended (rather than on foods to avoid). It may be helpful to explore and specifically address some common questions about food (table 6).

•Counsel family members about these same concepts and, particularly, that they should avoid criticizing the adolescent about their eating habits or body weight.

More details on strategies to support healthy approaches to weight control are discussed separately. (See "Prevention and management of childhood obesity in the primary care setting".)

ACKNOWLEDGMENT — 

The UpToDate editorial staff acknowledges Kathleen J Motil, MD, PhD, and Debby Demory-Luce, PhD, RD, LD, who contributed to earlier versions of this topic review.