Between 9 and 24 months of age, infants and toddlers undergo a wide array of developmental changes: crawling turns to walking, garbled words become meaningful two-word sentences ("want that", "all done"), and the breast or bottle gradually makes way for foods of the family table.1,2
Just as their physical abilities change and advance in so many ways, so do their nutritional needs. Specifically, during this period of dietary transitions, older infants and toddlers become vulnerable to energy and nutrient imbalances (deficiencies or excesses) when high-calorie and/or low-nutrient foods from the family diet crowd out the nutrient-rich foods of the infant diet.
Precisely when and how older infants and toddlers make the transition to the family diet can be as varied as the children who make the transition and the families caring for them. The vast majority of parents and caregivers in the US begin by offering breast milk or iron-fortified infant formula throughout the first months of life, then introduce single-grain infant cereals, and pureed fruits and vegetables when the infant is developmentally ready. While it is true a small percentage of infants are offered their first taste of French fries, dessert or candy before their sixth-month birthdays,3 significant amounts of table foods aren't prominent in the diet until 7 to 8 months of age, when 8% of an infant's average calorie intake is derived from table food.4 By 9 to 11 months of age, average caloric intake from table foods jumps to 25% and steadily climbs to 63% or more by the end of the second year of life, with the remaining calories derived from cow's milk and other beverages. During this critical period, parents must be vigilant to feed their children a wide assortment of healthy foods while acting as positive role models at the family table. Indeed, familial food patterns strongly influence the eating behaviors of older infants and toddlers.5
The recent Feeding Infants and Toddler Study (FITS),6 an examination of the diets of infants and toddlers in the US today, revealed specific nutritional issues present in this vulnerable and impressionable age group. This paper focuses on the vast changes that occur in food consumption patterns during the transition from baby foods to table foods, the associated affects on energy and nutrient intakes, and their implications on young children's health and long-term eating patterns. These changes are best seen when comparing the opposite ends of the table food energy intake continuum, i.e., food and nutrient consumption patterns of those infants and toddlers taking in the greatest and least amounts of energy from table foods in a day.
Examining the Current Trends in Young Children's Diets
While parents may intend to feed their young children foods that will support healthy growth and development, the diets of most children over the age of 2 do not satisfy current Dietary Guidelines.7-9 In fact, despite recent improvements in the nutrient density of diets for children 1 to 18 years old, diet quality has declined as age increases among 2 to 9 year olds. Most children in this age range have diets rating as "needs improvement" or "poor," according to standards set by the US Department of Agriculture via its assessment tool, the Healthy Eating Index.9 The USDA findings highlight the importance of establishing healthy eating habits during the critical years of very early childhood.
For the most part, pediatric nutrition studies have focused on the eating patterns of older children and adolescents, who have already made the transition to foods from the family table. In order to determine what infants and young children in the US are eating, FITS researchers collected 24-hour dietary recall for over 3,000 4 to 24 month olds6 which captured energy and nutrient information from all foods and beverages (baby and non-baby), as well as breast milk and dietary supplements.10-11 Percentage of energy derived from each of the food categories of breast milk, infant formula, cow's milk, infant cereals, baby foods and baby juices (only those marketed for infants and toddlers), other beverages, and table foods was estimated for each age group. To examine the diets of those transitioning to table foods, the infants and toddlers surveyed were divided into the age groups of 9 to 11, 12 to 14, 15 to 18, and 19 to 24 months.
Of great interest are the differences between and among age groups regarding the percentage of energy derived from table foods vs. milks and/or formula and distinctively baby foods (Figure 1). As would be expected, the percentage of energy consumed from commercial baby foods, baby beverages, and infant cereals peaks at 29% at 7 to 8 months, then declines with age thereafter as more and more table foods enter the diet. While infants 9 to 11 months of age only obtain a mean percentage of 25% of their energy from table foods, parents of toddlers ages 19 to 24 months attribute 63% of their children's energy intakes to these foods, illustrating how rapidly diets change in only a few short months.
In general, as age increases so does the percentage of energy acquired from table foods, and with that the mean intakes of energy, macronutrients and total grams of food also increase. In order to take a closer look at how the transition to table foods affects both consumption patterns and nutrient intakes, FITS researchers divided infants and toddlers in each age group into quartiles based on the percentage of energy they consume in a day from table foods. A "high" quartile refers to infants and toddlers within a given age group who consume the highest percentage of energy from table foods. A "low" quartile refers to those in each age group who consume the lowest percentage of energy from table foods. Segmenting the data in this way clearly illustrates that infants and toddlers in the highest quartile of daily energy from table foods add table foods to their diets in higher proportions and at faster rates than infants and toddlers in the lowest quartile (Figure 2).
Given that table foods have different nutrients than baby foods and are eaten in different proportions, the difference in the rate of table food introduction has an associated impact on the nutrient intakes of infants and toddlers within each quartile. For example, compared with infants and toddlers in the lowest quartiles, those in the highest quartiles have significantly higher intakes of energy, carbohydrate, protein, total fat, sodium, folate, and fiber. In contrast to these findings, young children 9 to 24 months in the lowest quartiles have higher intakes of some nutrients — particularly vitamin C and calcium — than those in the highest quartiles.
These data suggest that parents of older infants and toddlers who are consuming higher percentages of their daily energy intake from table foods need to make very careful choices about which foods they offer at snacks and meals. Like all humans, infants and toddlers have relatively finite daily energy and nutrient requirements. Infants' requirements, however, are paired with a uniquely small stomach capacity. The food choices, serving sizes, and proportion of nutrients offered to fulfill those requirements may vary, but total volume remains relatively constant. As a practical matter, that means every calorie counts.
Figure 3 compares the mean energy intakes from table foods between infants in the highest and lowest quartiles, which essentially mirrors total daily energy intake from all table foods within each age group. However, significant differences in nutrient and specific food intake patterns between quartiles exist. For example, 9 to 11 month-old infants in the lowest quartile of energy intake from table foods consume 862 kcal of energy each day. Of those, up to 8% — or 70 calories — are from table foods. This number of calories equates to half of a serving of sugary soft drink or French fries, or a medium-sized apple. On the other hand, 9 to 11 month-old infants in the highest quartile consume 1,138 kcal of energy each day and, of those, 39 to 92% — or 444 to 1,047 calories — are from table foods. This pattern holds true throughout the second year of life, a time when increased energy intake from table foods correlates with an increase in calories in the overall diet. For toddlers in the highest quartile of energy intake from table foods, this means that not only are table foods added to their diets faster and in greater proportions than toddlers in the lower quartile, but that table foods make up a higher proportion of their total daily calorie intake. Once table foods make up more than half of all energy consumed, which occurs among toddlers 19 to 24 months old across all quartiles, this discrepancy fades.
FITS data suggest that infants and toddlers in the highest quartiles of energy intake from table foods may be consuming more energy-dense table foods and/or more food in general. For the most part, the mean intake of total grams of food follows energy intake patterns. Toddlers aged 19 to 24 months are an exception to this trend, as those in the lowest quartile consume significantly more grams of foods but about the same level of calories as toddlers in the highest quartile of table food intake. This finding suggests a higher consumption of energy-dense food items among those who consume more table food energy. Compared to those in lower quartiles, young children aged 9 to 14 months in the highest quartiles are more likely to consume cheese, yogurt, mixed dishes, macaroni and cheese, presweetened cereals, bread, rolls, and biscuits.
Eating Foods from the Family Table
To arrive at an understanding of how consuming different proportions of table foods affects nutrient intakes at different stages, the foods eaten by FITS infants and toddlers were segmented and analyzed for each group by table food energy quartiles. Between the ages of 9 to 11 months and 19 to 24 months, a progression from breast milk or infant formula to cow's milk, from baby food meats to table food meats, and from infant cereals to ready-to-eat cereals, breads, pasta, rice, and other grain products was observed across all quartiles. Food consumption patterns were analyzed by focusing on the percentage of children consuming foods from the various food groups, rather than the amounts of food consumed. (It should be noted, however, that nutrient estimates take into account the amounts of food consumed.)
Importantly, for most every food group analyzed, the often significant differences in consumption patterns between quartiles in the early months of table food introduction fade by the second birthday. This suggests that across the board, the healthy eating habits initiated during the transition from an all-milk diet to baby foods are not maintained once toddlers make the transition to foods from the family table.
Many infants and toddlers consume two or more types of milk (breast, infant formula, and cow's) at least once in a day (Figure 4). Infants and young toddlers 9 to 14 months consuming a larger percentage of their calories from table foods are more likely to be breastfeeding and/or consuming cow's milk, and are less likely to consume formula than those in the lowest quartile. These findings suggest that 9 to 14 month old infants fed formula are likely taking in more of their daily calories as formula, thus have a lower percentage of calories from table foods.
Of interest to pediatric professionals is the finding that the majority of parents are heeding AAP advice to delay cow's milk introduction until 12 months of age. There are exceptions, however, with older infants in the highest quartile of energy from table foods more likely to consume cow's milk before their first birthday. Very few differences were seen in cow's milk consumption patterns between those in the upper and lower quartiles. However, 10 to 40% of infants and toddlers 12 to 24 months old are being fed reduced-fat or skim milk, contrary to AAP recommendations to offer only whole milk for the first two years of life.12 Whole milk is a good source of fat, which aids in the absorption of vitamin E.
Cereal is commonly consumed by children regardless of age or quartile of table food energy intake. The expected pattern of reduced infant cereal consumption during the transition to table foods is shown in Figure 5. The data also show an inverse relationship between infant cereal and a high percentage of calories from table foods. In other words, older infants and toddlers consuming the least amount of energy from table foods in a day are more likely to consume infant cereals. Furthermore, 9 to 11 month-old infants in the lowest quartile are more likely than those in the highest quartile to consume infant cereal as opposed to non-infant, ready-to-eat (RTE) cereal. This pattern begins to reverse around the first birthday when non-infant cereals figure more prominently in the diet. Pre-sweetened RTE cereals are consumed by children in all quartiles of energy intake. Not surprisingly, toddlers in the high table food energy intake quartiles are more likely to consume pre-sweetened RTE cereals.
Fruits and Vegetables
Most children do not eat the recommended five servings of fruits and vegetables a day,13,14 a sad realization in light of mounting research indicating that a diet high in fruits and vegetables is associated with reduced risk of several chronic diseases later in life.15 In fact, regardless of table food energy intake quartile, roughly one quarter of all infants and toddlers did not consume a single fruit or vegetable on the day of the sample (Figure 6).
Arguably, the single most important "food finding" of FITS is the decrease in overall fruit and deep yellow vegetable consumption during the second year of life. Specifically, as older infants make the transition from baby food fruits and vegetables to table food fruits and vegetables, there is an associated drop in deep yellow vegetable consumption and vitamin A and C intake. Moreover, as these healthy foods exit the diet, they are replaced with less healthy alternatives (e.g., French fries).
For example, vitamin A and C-rich deep yellow baby food vegetables such as carrots and squash are popular among 9 to 14 month-old children who consume the least amount of energy from table foods in a day. But very few infants and toddlers across all age groups (<1% to 14%) consume any deep green vegetables, such as spinach and broccoli. Toddlers in the highest table food energy quartile consume more vegetables than toddlers in the lowest quartile. However, the vegetables they are most likely to eat are potatoes, particularly in the form of fatty, salty French fries.3,13 This alarming trend begins in infants as young as 9 to 11 months old, and is especially prevalent in children who incorporate a greater percentage of table foods into their diets at a comparatively early age. This suggests that the earlier table foods are introduced into the diet, the more likely a young child is to consume potatoes and eat fewer deep yellow vegetables than when they are consuming jarred baby vegetables.
While young children may be consuming adequate quantities of micronutrients, this fact cannot compensate for the glaring lack of fruits and vegetables in the diets of many children today.3,8,13,14,16 From an infant's first experience with table foods, there exists the opportunity to introduce a variety of forms and types of fruits and vegetables. Pureed vegetables and very soft vegetable dices represent easy ways to include vegetables in even a very young child's diet on a regular basis.
Lean meats are a healthy food choice, rich in protein, iron and zinc. Figure 7 shows that non-baby food meats are added to the diet later than any other kind of food. When they do become an established component in the diet during the second year of life, both toddlers in the highest and the lowest quartiles for table food energy intake are consuming hot dogs and sausages at a significant rate. When these higher fat, lower nutrient meat choices come into the diet, they displace the nutritional contributions that could be made by plain lean meats, such as beef, poultry, pork, and fish.
Sweets, Sweetened Beverages and Salty Snacks
For nearly all young children, energy-dense, nutrient-poor foods, such as candy, carbonated sodas, fruit-flavored drinks, and salty snacks are introduced into the diet as the transition from baby foods to table foods occurs (Figure 8). Greater and greater percentages of children consume these foods as age rises, until by 15 to 24 months, 90% of toddlers in the top quartile consume a sweet such as cookies, cakes, and candy in a day. Up until 18 months of age, the percentage of infants and toddlers drinking carbonated sodas and fruit-flavored drinks is higher in the highest quartile; this difference levels out in the oldest age group. Although those in the highest quartile in all age groups are more likely to consume chips and other salty snacks such as cheese puffs, by 19 to 24 months of age about one quarter of all toddlers consume these snacks in a day.
While strictly prohibiting the consumption of any sweets or salty snacks is not recommended, parents should be cautioned to be less liberal with the high-calorie, low-nutrient foods they offer to their young children. Instead, they should offer nutritious snacks such as yogurt, pretzels and cheese. Similarly, carbonated sodas and other sweetened beverages can be sources of unnecessary sugars and caffeine, and can contribute to risk of dental caries. Parents should be advised to limit their young children's intake of these beverages.
Overall Nutrient Assessment
Regardless of which quartile they fell into, nearly all children included in FITS met their nutrient requirements, perhaps due to the wide availability of fortified foods. However, several possible gaps in the diets of different segments of the population surveyed presented themselves.
For example, data from other smaller studies of toddlers suggest that deficiencies resulting from low intakes of zinc, vitamin C, vitamin E, and fat may be of concern for some toddlers.17,18 Potential iron deficiency — which has been documented with high prevalence among 1- to 4-year-old children — is an issue in the diets of infants and toddlers transitioning to table foods that parents and caretakers should be made aware of.17,19
FITS data analysis suggests that, as 9 to 11 month-old infants begin to eat more table foods, consumption of iron-fortified infant cereals and formula may taper off, contributing to the lower iron intakes documented in the highest quartile for this age group (Figure 9). Since the transition period of young children's food patterns occurs at a stage when adequate iron intake is critical, special attention should be paid to ensure that intake is sufficient.17,19,20
Lower calcium intake is observed for toddlers aged 15 to 24 months who obtain a greater percentage of their total energy from table foods (Figure 9), related to the fact that fewer toddlers in this quartile are consuming milk as compared with their peers in the lower quartiles. Unfortunately, it may be that the milk lacking in the diets of those toddlers in the highest quartiles is being replaced by sweetened beverages, which is becoming commonplace in the diets of almost half of toddlers 19 to 24 months old. This trend may lead to a general preference for soft drinks and sweetened beverages over milk,3,20,21 perhaps contributing to the inadequate intake of calcium that is prevalent in older children and adolescents today.7,9,16
Obesity in Young Children
Much attention is rightfully being paid to the increasing prevalence of overweight and obesity among very young and preschool-aged children. Based on national 1999-2000 data, 10% of 2 to 5 year olds in the US are overweight, and that percentage may be climbing.22 For the health of these children now, and the health of our country in the long term, the nutritional attitudes and habits that are shaped as young children transition from an all-milk diet to the varied diet of the family2,18,23 must be carefully managed. In particular, special care must be taken not to overfeed and increase energy intake above what is needed for optimal growth and development.
Infants and young children are very capable of regulating their energy intake if permitted to eat when they are hungry and stop when they are full. However, emerging toddler independence and a keen willingness to express it can lay the foundation for overfeeding and mealtime power struggles. Parents and other caregivers can avoid these undesirable by-products of normal toddler development by offering a variety of healthy, colorful foods at meals and snacks, then respecting their child's innate knowledge of how much of each to eat.
Importantly, FITS infants and toddlers in the higher quartiles of energy intake from table foods do not exhibit any trends of being heavier or older than others within their age groups, which indicates that the food and nutrient intakes, as recorded, relate to the percentage of the total energy that these children derive from table foods and to which table foods are consumed. Alternatively, it may be that the children's intake of table foods was overestimated by their parents or caregivers relating the information for the 24-hour recall. One certain conclusion, however, is that most infants and toddlers consume more energy than current recommendations allow.24 While this may be due to caregivers 1) mistakenly overreporting their infant's or toddler's food intake or thinking that "more is better", or 2) under-estimating how much energy their infants and toddlers may need,25 overfeeding appears to be an important issue in young children's diets for parents and pediatric professionals to address.
Shaping Food Attitudes and Preferences, One Day at a Time
Parents should be made aware that they have a great influence on their children's food preferences, and that these preferences are shaped early on.2,18,23,26 In fact, it has been shown that once food preferences are established — around two to three years of age — they remain fairly stable until at least 8 years of age.21 So, whether infants and toddlers transitioning to table foods are exposed to fruits and vegetables, or to foods of little nutritional value and high in energy, sugar, and fat, future food preferences and consumption will likely reflect those early exposures.18,23
It is important to note that between 9 and 24 months of age, children's self-feeding skills will reflect their individual readiness to incorporate certain foods into the diet at appropriate times.27 Neglecting to observe these natural stages of development, and feeding a child too many different table foods too quickly, may eventually lead to the feeding of fewer foods and a less varied, less balanced diet. Further research on which foods are consumed as table foods account for greater and greater percentages of a child's total energy intake at various stages of development will help to explain this connection more fully.
During the transition to table foods, parental feeding practices help mold their children's predispositions for self-regulating energy.2 For the benefit of toddlers' eventual dietary self-selection, it is vital that parents strive to offer their children highly nutritious — and delicious — foods, moderate the consumption of energy-dense foods, and allow their children's own appetites to guide how much they eat at each meal.1,2,4,5,18
While food choices and habits may be influenced by numerous factors over the course of a lifetime, early childhood is the time when a foundation is laid for all that is to come.2,18,28 Clearly, many parents would benefit from enhanced guidance on the timing of various transitions, how to transition, which foods to emphasize, and which foods to moderate as children progress toward family fare.
As FITS is the first study to examine increasing energy from table foods at various stages of development, supplementary information on how the transition to table foods affects nutrient intakes and consumption of various foods is scant. The data collected in this study are cross-sectional, and do not reflect nutritional intakes over a period of time as infants are weaned and slowly transition to table foods. However, insight may be gained into the possible influence that acquiring a lesser vs. greater percentage of energy from table foods at different ages has on the nutrient intakes and food consumption of infants and toddlers.
As infants and toddlers transition to table foods, parents should be made aware that repeatedly offering a wide variety of nutritious, developmentally appropriate foods — particularly fruits and vegetables — will help establish healthy habits in both childhood and into adulthood. Also, since the second year of life is a particularly vulnerable period in terms of iron deficiency, parents should be alerted to a potential lack of iron in the diets of their toddlers, and be encouraged to offer foods that are good sources of iron, such as meats, iron-fortified infant cereals, unsweetened ready-to-eat cereals, and other high-iron grain products. Calcium intake is another concern during this critical period of growth and development; parents can encourage adequate intake by offering whole milk and other nutritious dairy foods, rather than sweetened beverages and low-nutrient snacks.
Being able to discern one's own hunger and satiety cues is an important lesson to learn, which parents can reinforce by feeding their infants and toddlers only when hungry, not forcing or bribing their children to eat, and stopping when their children indicate that they are full. Although parents may not realize it, as they feed their inquisitive infants and toddlers their first foods, they are helping to establish eating habits and food preferences that will stay with their children for many years to come, habits and preferences that could help support their children's good health today and well into the future.
Ronette Briefel is a senior fellow and nutritional epidemiologist at Mathematica Policy Research, Inc. in Washington, DC., and Co-Principal Investigator of the Gerber Feeding Infants and Toddlers Study (FITS). Dr. Briefel has over 25 years of experience in public health policy and epidemiologic research on the nutritional and health status of the US population and high-risk groups, and served on the Institute
of Medicine's Committee on Dietary Risk Assessment in the Special Supplemental Feeding Program for Women, Infants, and Children (WIC). Prior to coming to Mathematica in 1999, she was Nutrition Policy Advisor with CDC's National Health and Nutrition Examination Survey (NHANES).