Dietary history and recommended dietary intake in children

INTRODUCTION — Reviewing the dietary history in the context of recommended dietary intake is an important component of nutritional assessment in children. The goal of nutritional assessment in childhood is to identify and prevent nutritional disorders such as malnutrition and overweight, as well as the increased morbidity and mortality that accompany them. Other UpToDate topic reviews related to dietary recommendations and counseling are:

●Dietary recommendations:

•(See "Introducing solid foods and vitamin and mineral supplementation during infancy".)

•(See "Dietary recommendations for toddlers and preschool and school-age children".)

•(See "Estimation of dietary energy requirements in children and adolescents".)

●Nutritional assessment:

•(See "Indications for nutritional assessment in childhood".)

•(See "Measurement of growth in children".)

•(See "Clinical evaluation of the child or adolescent with obesity".)

•(See "Laboratory and radiologic evaluation of nutritional status in children".)

•(See "Malnutrition in children in resource-limited settings: Clinical assessment".)

●Specific types of diets:

•(See "Adolescent eating habits", section on 'Fast foods'.)

•(See "Vegetarian diets for children".)

•(See "Organic foods and children".)

DIETARY HISTORY — A dietary history should determine the quantity and quality of the food that is consumed by the infant or child, the eating behaviors of the child, and the beliefs of the family. Nutrient intake then is compared with the age-specific recommended intake to assess the likelihood of undernutrition or overeating.

Components — The initial dietary history explores:

●Type of food provided to the infant or child

●Number of meals and snacks provided per day

●Use of a special diet or formula

●Use of herbal or other alternative supplements

●Vitamin and mineral supplements (if any), and whether these are given consistently

●Any food allergies, intolerances, or avoidances

●Any unusual feeding behaviors or difficulty feeding

●Any difficulties with chewing or swallowing

Dietary history in infants

Breastfed infants — Human milk is the recommended primary source of nutrients for healthy term infants during the first year of life. The assessment of the adequacy of the dietary intake of the breastfed infant is based on the following (see "Initiation of breastfeeding"):

●Frequency and duration of breastfeeding – The breastfed infant should be allowed to nurse within an hour after birth. The exclusively breastfed infant typically nurses every two to three hours while awake, or 8 to 12 times per day. After suckling at one breast, the infant should be repositioned at the second breast. The average duration of each nursing is 5 to 20 minutes per breast. "Appetite spurts" or periods of increased feeding frequency may occur at or near 10 days, four weeks, and three months of life.

●Frequency of urination and stooling – The breastfed infant usually has at least six wet diapers per day after the first week of life and an average of four bowel movements per day when consuming an adequate amount of milk. However, stooling patterns in healthy breastfed infants vary markedly, ranging from less than one per day to one after each feeding [1,2].

●Rate of weight gain – Breastfed infants usually gain 15 to 30 g/day during the first six months as they grow from an average weight of approximately 3.5 kg at birth to 7.5 kg at six months [3]. Use of growth charts based on World Health Organization standards provides the most accurate assessment of a breastfed infant's growth. (See "Normal growth patterns in infants and prepubertal children", section on 'Normal patterns' and "Measurement of growth in children", section on 'Recommended growth charts with calculators'.)

●Supplements – Ask about vitamin D supplements, which are recommended for all breastfed infants. (See 'Vitamins and minerals' below.)

Formula-fed infants — Iron-fortified infant formulas are acceptable substitutes when mother's milk is not available. The assessment of the adequacy of the dietary intake of the formula-fed infant is based on the following:

●Type of formula – The primary distinction among infant formulas is their protein source, which classifies them into the following categories:

•Standard cow's milk formulas (nonhydrolyzed or "intact")

•Partial whey hydrolysate formulas

•Extensively hydrolyzed formulas (whey- and casein-based)

•Soy protein-based formulas

•Amino acid-based formulas

•Goat's milk-based formulas

All infant formulas are designed to be nutritionally complete and have ratios of macronutrients (protein, fat, and carbohydrate) that are similar to breast milk. A few formulas used for infants with specific metabolic disorders may be nutritionally incomplete, but these are highly unusual. Formulas are sometimes changed empirically for nonspecific symptoms such as reflux or irritability, but a favorable response may or may not be causally related. Extensively hydrolyzed or amino acid-based formulas are used predominantly in infants with established food allergy or protein intolerance and infants at high risk of developing an allergy. These considerations are discussed in separate topic reviews. (See "Introducing formula to infants at risk for allergic disease" and "Food protein-induced allergic proctocolitis of infancy".)

●Formula preparation – Infant formulas are available in three forms: ready-to-feed liquid, concentrated liquid, and powder. All three types of formula preparations are nearly identical in nutrient composition, although small differences may exist for technical reasons. The clinician should review formula preparation with the caregiver to confirm that it is prepared according to manufacturer's directions:

•Concentrated liquid formula should be mixed with an equal volume of potable water.

•Standard powdered infant formulas should be prepared according to directions, usually as 1 scoop per 2 ounces of water; the water should be added to the mixing container or bottle first, followed by the powder. Specialized infant formulas, such as the amino acid-based formula, may have different proportions of powder to water.

●Dietary energy intake – Infant formulas designed for healthy full-term infants contain 0.67 kcal/mL (20 kcal/oz) when properly prepared. Other formulas or formulas with additives may have different caloric densities. The daily energy intake of the formula-fed infant can be determined by multiplying the caloric density of the formula by the volume of formula consumed.

●Frequency and volume of feedings – The frequency with which the formula-fed infant feeds is highly variable because of the variability in gastric emptying time (one to four hours). Ideally, the feeding schedule should be regulated "on demand" by the infant. Most infants rapidly increase their intake from 30 to 90 mL (1 to 3 oz) every three to four hours during the first week of life. After the first week of life, most infants will demand six to nine feedings per 24 hours. Some infants will be satisfied with feedings every three to four hours, whereas others will require feedings every two to three hours. Most young infants require feedings throughout the day and night.

Solid foods — Solid foods (also known as complementary foods) are optimally introduced between four and six months of age. The dietary history should include the quantity, frequency, and variety of these foods. Intake of iron-rich foods (eg, fortified infant cereals and meats) is particularly important. (See "Introducing solid foods and vitamin and mineral supplementation during infancy".)

Dietary history in children and adolescents — No standard approach exists for estimating the dietary intake in children. Several methods that differ in ease of use and reliability are available [4].

Dietary recall — The dietary history of the child can be assessed with a 24-hour dietary recall or a food frequency questionnaire. These methods of dietary analysis can be misleading because the child or caregiver must rely on memory to describe typical eating patterns.

●24-hour dietary recall – For the 24-hour dietary recall, the child or caregiver is asked to report the type and quantity of food consumed in the preceding 24 hours. This approach provides some quantitative information but can be misleading because it does not accurately assess foods that are consumed intermittently [5].

●Food frequency questionnaire – A food frequency questionnaire is more qualitative but may provide a better assessment of the intake of episodically consumed foods [6]. The questionnaire consists of a finite list of foods, beverages, or supplements with response categories to indicate usual frequency of consumption over a specific time period. The questionnaire also elicits information on usual portion sizes and, in some cases, includes portion size images to assist with accuracy. Food frequency data can be used to assess total dietary intake and/or particular aspects of diet.

One study that used a food frequency questionnaire found that 6^th and 7^th grade students could provide valid estimates of intake of calories, carbohydrates, calcium, phosphorus, iron, and vitamin C, while 4^th and 5^th grade students could not [7].

Dietary diary — The dietary diary is a three-day written food record that lists all foods consumed during a period of two weekdays and one weekend day, performed while the child is at home. It is a more valid tool to quantify actual dietary intake compared with the dietary recall methods described above. The parent or caregiver records the types of food served to the child, manner in which the food was prepared, and use of additional condiments. The amount of food consumed should ideally be determined by measuring the weight of each food using a digital scale; if this is not possible, record the food volume using common household measurements. Increasingly, caregivers are using smartphone apps to record dietary intake.

Even when caregivers attempt to record intake objectively, estimates are imprecise because anxious parents/caregivers tend to over- or underestimate the child's food consumption, depending on the nature of the nutritional problem. Despite these difficulties, every effort should be made to document the possibility that altered dietary intakes contribute to the nutritional problem of the child. Unusual meal patterns such as excessive fruit juice consumption may become apparent from the written document and serve as an explanation for poor weight gain in the young child [8].

Infants and children fed enteral nutrition — "Blenderized" feedings prepared from foods at home are increasingly used for children who are dependent on enteral feeds [9]. In some cases, families choose this approach because of a preference for feeding their child unprocessed organic foods with minimal sugar. The recipe should be reviewed periodically by an experienced clinician to ensure that the blenderized formula provides adequate fluids, micronutrients, and macronutrients. (See "Overview of enteral nutrition in infants and children", section on 'Formula selection'.)

Complementary feeding — Complementary (solid) foods are added between four and six months of age; most infants in this age group have sufficient neuromuscular development and coordination to swallow puréed foods without complications. Timely introduction of complementary foods is necessary to optimize nutritional and developmental progress [10]. (See "Introducing solid foods and vitamin and mineral supplementation during infancy".)

At approximately six months of age, the volume of human milk ingested becomes insufficient to meet the nutritional requirements of energy, protein, iron, zinc, and some fat-soluble vitamins (A and D). Between four and six months of age, the clinician should assess the infant's developmental readiness for complementary feeding:

●Loss of the primitive reflexes of extrusion, sucking, and rooting

●Attainment of truncal stability

●Ability to signal satiety by moving the head away from the spoon

Once complementary foods are introduced, the clinician should periodically review the infant's intake and the variety of foods offered, particularly whether the diet includes foods high in iron and/or fortified complementary foods or vitamin mineral supplements. Fruit juices and foods with added sugars should generally be avoided. (See "Introducing solid foods and vitamin and mineral supplementation during infancy", section on 'What to feed and how to advance'.)

Determining nutrient content — Once a history has been obtained, food servings should be converted into nutrient content to allow comparison with the dietary reference intakes (DRIs) for specific nutrients. This can be done using a computed nutrient database available from a variety of sources including commercial software packages; a variety of Food Composition Databases are listed on the United States Department of Agriculture website. Consultation with a dietitian is helpful in calculating the nutrient content of the child's diet. (See 'Dietary reference intakes' below.)

Alternatively, Atwater conversion factors can be used to estimate the energy content of the diet based on the reported intake of each macronutrient. The following conversion factors are used:

●Protein – 4 kcal/g

●Carbohydrate – 4 kcal/g

●Fat – 9 kcal/g

TERMINOLOGY FOR DIETARY STANDARDS — Two sets of standards have been developed to describe optimal nutritional intake: dietary reference intakes (DRIs) and daily values (DVs). These standards are described in the following sections.

More detailed discussion of dietary recommendations, with specific tips for counseling, are discussed in the following topic reviews:

●(See "Introducing solid foods and vitamin and mineral supplementation during infancy".)

●(See "Dietary recommendations for toddlers and preschool and school-age children".)

●(See "Estimation of dietary energy requirements in children and adolescents".)

Dietary reference intakes — DRIs are determined by the National Academy of Sciences [11]. They are comprised of four standards, each of which describe a different aspect of optimal nutritional intake in a variety of populations, which can be used to plan and assess the diets of healthy individuals or populations. The components of the DRIs include:

●Recommended dietary allowance (RDA) – The RDA is the level of dietary intake that is sufficient to meet the daily nutrient requirements of 97 percent of the individuals in a specific life stage group. It is determined by the National Academy of Sciences based on the best available research data. Consumption of nutrients below the RDA does not necessarily constitute a deficiency, because absolute nutrient requirements for individuals usually are not known with certainty. However, the further the intake is below the RDA, the more likely that a deficiency will develop. The average intake of most nutrients by children in the United States exceeds 100 percent of the RDA, with the exception of iron, calcium, and zinc [12].

●Estimated average requirement (EAR) – The EAR is the daily intake value for individual nutrients that is estimated to meet the requirement in 50 percent of the individuals within a given life stage group.

●Adequate intake (AI) – The AI represents an approximation of the average nutrient intake that sustains a defined nutritional state, based on observed or experimentally determined values in a defined population. This value is used when scientific data are insufficient to calculate an EAR.

●Upper tolerable level (UL) – The UL is the maximum level of daily nutrient intake that is likely to pose no risk of adverse health effects in almost all individuals in the specified life stage and sex-based group.

DRIs are defined for the following life stages:

●Infancy (0 to 6 months and 6 to 12 months)

●Early childhood (1 to 3 years)

●Late childhood (4 to 8 years)

●Early adolescence (9 to 13 years)

●Late adolescence (14 to 18 years)

DRIs (RDA, AI, and UL) have been provided for macronutrients (carbohydrates, fiber, fat, protein, and amino acids) and various vitamins and minerals (table 1A-B) [11,13-15]. The estimate of the nutrient content of an individual's diet should be compared with the age- and sex-specific DRI, with the caveat that these standards meet or exceed the nutrient needs of nearly all healthy children but do not take into account the nutrient needs of children with acute or chronic illness (table 2) [16]. More detailed information is available at the Food and Nutrition Information Center.

Daily values — The term daily values (DVs) is determined by the US Food and Drug Administration and used on a food label to provide the consumer with information about the nutritional value of various food products (table 3). The DV is often, but not always, similar to the RDA or AI for that nutrient. This is because the DV represents the highest RDA/AI within a broad age range (most commonly adults and children ≥4 years).

The DV consists of one of two terms, depending on the nutrient:

●Daily reference value (DRV) – DRVs are provided for total fat, saturated fat, cholesterol, total carbohydrate, dietary fiber, sodium, potassium, and protein.

●Reference daily intake (RDI) – RDIs are provided for vitamins and minerals, excluding those listed above. These were formerly known as United States Recommended Dietary Allowances (USRDAs). The name change was necessary to avoid confusion with the RDA, which is determined by the Institute of Medicine, as described above. (See 'Dietary reference intakes' above.)

The nutrients for which DVs were established reflect the common health problems for the people of the United States, including obesity, hyperlipidemia, hypertension, and osteoporosis. Food labels also list nutrition information as a percentage of DVs (%DV), based on a 2000-calorie daily energy intake. A 2000-kcal energy intake was used as the reference because it approximates the energy requirement for postmenopausal females, the group of individuals who have the highest risk for excessive dietary energy and fat intakes. These values should be adjusted for individuals whose energy intake is significantly above or below this level, including most children.

OVERVIEW OF DIETARY RECOMMENDATIONS

Energy needs — An individual's target for energy intake (caloric needs) can be estimated based on their age, sex, and activity level.

Infants — Average energy requirements in healthy infants are approximately 110 kcal/kg/day at one month of age, 95 kcal/kg/day at three months of age, and 80 kcal/kg/day between 6 and 12 months of age (figure 1) [17]. This intake results in weight gain of 15 to 30 g/day during the first six months of life and 6 to 15 g/day between 6 and 12 months of life. Actual energy requirements for an infant vary depending on individual characteristics, including medical needs and catch-up growth. Energy requirements for breastfed infants are up to 15 percent less than for formula-fed infants. However, undernourished infants with acute or chronic illness may require increased energy intakes in the range of 150 to 180 kcal/kg/day and higher weight gains of 50 to 60 g/day to maintain good nutritional health.

Children and adolescents — Recommended energy intakes in the United States are reflected in this calculator [18]. Similar information about recommended energy intake is shown in this table (table 4).

Factors that influence energy requirements for children and adolescents are discussed in a separate topic review. (See "Estimation of dietary energy requirements in children and adolescents".)

Dietary composition

Fat, carbohydrates, and protein — Targets for energy-producing macronutrients are expressed as a percentage of the total energy in the diet:

●Total fat – Varies by age group:

•Children one to three years – 30 to 40 percent of total daily calories

•Older children and adolescents – 25 to 35 percent of total daily calories

•Adults – 20 to 35 percent of total daily calories

●Saturated fat – Less than 10 percent of total daily calories (and minimize intake of trans fats as much as possible)

●Carbohydrate:

•Approximately 45 to 65 percent of total daily calories

•Consume less than 10 percent of calories per day from added sugars

●Protein:

•Children one to three years – 5 to 20 percent of total daily calories

•Older children and adolescents - 10 to 30 percent of total daily calories

Target intakes for these macronutrients, using typical caloric needs for each age group, are outlined in the tables (table 1A-B).

Fiber — Target intake for dietary fiber is at least 25 g per 2000 kcal. For children, an age-based target fiber intake has been suggested, with targets of 30 or more g/day for adolescents [19,20]. A more modest target can be estimated by recommending daily intake of fiber in grams equal to the child's age plus 5; this provides a goal that is more realistic for some children [21]. One serving of most fruits or vegetables (eg, one whole apple or pear, or one-half cup of vegetables) equals approximately 3 g of fiber (table 5).

Fiber intake is encouraged because it helps prevent constipation and because high intake is associated with lower visceral fat mass and markers of inflammation in adolescents [22]. Long-term benefits of fiber are implied by observed associations with decreased risk for cardiovascular events, diabetes mellitus, and all-cause mortality in adults. High-fiber diets are also associated with beneficial gastrointestinal microbiota [23]. (See "Healthy diet in adults", section on 'Fiber'.)

Vitamins and minerals

●Infants – For breastfed infants, supplementation with vitamin D (400 international units/day) is recommended starting at discharge from the birth hospitalization [24]. An alternate approach is to administer moderately high doses of vitamin D (4000 to 6400 international units [100 to 160 micrograms] daily) to the lactating mother. (See "Vitamin D insufficiency and deficiency in children and adolescents", section on 'Prevention in the perinatal period and in infants'.)

After four months of age, breastfed infants should have some form of iron supplementation (eg, in puréed meats, iron-fortified infant cereal, iron-rich vegetables, liquid iron supplement) to meet their requirement of at least 1 mg/kg elemental iron daily. Infants who are fed an iron-fortified formula (12 mg elemental iron per liter) do not need additional iron supplementation. (See "Introducing solid foods and vitamin and mineral supplementation during infancy", section on 'Mineral and vitamin supplementation'.)

●Dietary reference intakes (DRIs) – DRIs for vitamins and minerals in a healthy population are outlined in the following tables:

•Water-soluble vitamins (table 6) (see "Overview of water-soluble vitamins")

•Fat-soluble vitamins (table 7) (see "Overview of vitamin A" and "Overview of vitamin E" and "Vitamin D insufficiency and deficiency in children and adolescents" and "Overview of vitamin K")

•Trace minerals (table 8) (see "Overview of dietary trace elements")

•Iron, calcium, and zinc (table 1A-B) (see "Iron deficiency in infants and children <12 years: Screening, prevention, clinical manifestations, and diagnosis" and "Iron requirements and iron deficiency in adolescents" and "Zinc deficiency and supplementation in children")

EDUCATIONAL TOOLS — In the United States, the following tools are used to communicate nutritional goals to the consumer.

MyPlate — The recommended diet is reflected by the MyPlate tool, which was developed by the United States Department of Agriculture based on the Dietary Guidelines for Americans [25]. MyPlate replaced the Food Guide Pyramid in 2011 [26]. It emphasizes moderation, variety, and proportionality in food consumption and notes the importance of physical activity.

The MyPlate plan divides foods into five major groups: grains, vegetables, fruits, dairy, and protein. The plan suggests amounts of food that individuals should consume from the five major groups to meet their recommended nutrient intakes at different levels of energy intake. Nutrient and energy contributions from each group are calculated according to the nutrient-dense forms of foods in each group. Examples of dietary composition recommendations from the 1200- to 3000-calorie levels are provided in the table (table 9).

Recommendations for special populations and educational materials are available on the MyPlate website [26].

Food labels — Food labels express targets for energy-producing macronutrients using a reference 2000-calorie diet to calculate the daily value (DV). The DV target can be adjusted for individuals who consume substantially more or less than the reference diet [20,25,27]. (See 'Daily values' above.)

Food labels may be confusing for consumers because the DVs for fat, cholesterol, and sodium are presented as the uppermost limit that is considered desirable to consume, whereas the DVs for some vitamins and minerals are presented as the smallest desirable daily intake (eg, vitamin C, iron, calcium) (table 3).

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

●History and clinical assessment of infants

•Breastfed – Assessment of the adequacy of the dietary intake is based on the frequency and duration of breastfeeding, frequency of urination and stooling, and rate of weight gain. Breastfed infants usually gain 15 to 30 g/day during the first six months of life and typically gain more slowly than formula-fed infants between 3 and 12 months of age. (See 'Breastfed infants' above.)

•Formula-fed – Average energy intake is 110 kcal/kg/day during the first month of life, falling to approximately 80 kcal/kg by six months of age (figure 1), resulting in a weight gain of 15 to 30 g/day. However, undernourished infants with acute or chronic illness may require increased energy intakes in the range of 150 to 180 kcal/kg/day and higher weight gains of 50 to 60 g/day to maintain good nutritional health. (See 'Formula-fed infants' above.)

●Dietary history for children – No standard approach exists for estimating the dietary intake in children and adolescents. Methods include dietary recall, food frequency, a dietary diary, or various survey instruments. Once a history has been obtained, food servings should be converted into nutrient content to allow comparison with the targets for each nutrient. (See 'Dietary history in children and adolescents' above and 'Determining nutrient content' above.)

●Recommended intake – Quantitative targets for each nutrient are captured by the dietary reference intakes (DRIs), which consist of the estimated average requirement (EAR), recommended dietary allowance (RDA), adequate intake (AI), and upper tolerable level (UL).

DRIs are provided for macronutrients (carbohydrates, fiber, fat, protein, and amino acids) and most vitamins and minerals and vary by age group (table 1A-B). Targets for energy-producing macronutrients (carbohydrates, protein, and fat) are also expressed as a percentage of the total energy in the diet. (See 'Dietary reference intakes' above and 'Dietary composition' above.)

●Interpretation of food labels – Food labels in the United States report daily values (DVs), which suggest appropriate intake of a number of key nutrients based on a reference 2000-calorie diet (table 3). It is important to note that these values should be adjusted for individuals whose energy intake is significantly below or above this level, including most children. (See 'Daily values' above.)

●Energy needs – Approximate energy requirements range from 1000 calories/day in a healthy two-year-old child to 3000 calories/day in an active adolescent boy (table 4). Actual requirements vary considerably among individuals and are affected by chronic illness (table 2). (See 'Energy needs' above.)

●Diet education – Recommendations for dietary intake and balance are reflected in the MyPlate tool. This is an educational device that suggests amounts of food from each of five major food groups to meet recommended nutrient intakes at different levels of energy intake (table 9). (See 'MyPlate' above.)