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When should semisolid foods be fed to infants?
When Should Semisolid Foods Be Fed to Infants?
P E
R S P E
Peggy Pipes Developmental readiness, rather than chronological age, is the important criterion. There is today a wide range of opinions as to the appropriate time for the introduction of semisolid foods to infants and the long-term effects of the early introduction of these foods. Fomon estimated in 1975 that 71110 of energy consumed by infants in the United States was derived from semisolid foods-e.g., cereals, strained meats, vegetables and fruits, eggs and other foods-in the fIrSt month of life and that percentage increased to nearly 30% at five to six months. Concurrently, table food consumption increased during the first six to nine months. After this, the percentage of energy derived from semisolid foods decreased while that from table food increased to 46% at one year (1). Many feel that the addition of semisolid foods to infants' diets in the fIrSt weeks and months of life may contribute to obesity in infancy and later life. Others are concerned about allergic reactions or that salt, sugar and other additives in commercially prepared infant foods may predispose susceptible individuals to hypertension and poor food habits. On the other hand, there are those with years of experience in counseling mothers of young infants who feel that the early introduction of semisolid foods is appropriate. Parents often introduce semisolid foods without professional advice. Many respond to suggestions of relatives, neighbors and friends, often feeding semisolid foods to their infants in the belief that early addition of these foods will encourage their infants to sleep through the night. However, several studies have shown that addition of semisolids does not influence the infant's sleep patterns and does not result in an uninterrupted nights sleep for the caregiver (2,3). A number of criteria have been used as a basis for recommending the addition of semisolid foods to the infant's diet, such as chronological age, volume of milk the infant consumes, the need for iron-containing foods and developmental readiness (4-6). Some, such as chronological age alone, are quite arbitrary and ignore individual differences among infants and patterns of physical growth.
Development of Feeding Behavior Neurological maturation during infancy causes changes in the manner by which the infant secures food from the nipple or spoon. The young infant obtains milk by a rhythmic suckle with an up and down movement of the tongue. Semisolid foods fed by spoon in the fIrst months of life are ingested with these same stroking movements, the tongue projecting as the spoon is withdrawn. Frequently food is expelled from the mouth. At approximately 16 weeks, a more mature sucking pattern develops with the tongue moving back and forth instead of the earlier up and down motions. Spoon feeding is then easier because the
THE A UTHOR is Assistant Chief, Nutrition Section, Child Development and Mental Retardation Center, also Lecturer, School of Home Economics, University of Washington, Seattle, WA 98195.
C T I V E
child can draw in the lower lip as the spoon is removed. Infants are thus better prepared to consume semisolid food at 16 to 18 weeks than they have been previously. Foods no longer have to be diluted to an almost liquid consistency to achieve their acceptance (7). Infant's acceptance of semisolid food. Cereal is consistently reported to be the fIrst food added to the infant's diet; rice cereal is commonly the fIrst cereal grain to be offered. Parents thin the cereal to an almost liquid consistency, which permits the infant to suckle the mixture. Beal reported that cereal was generally accepted without problems between two and one half and three months. However, 32% of 37 infants willingly accepted cereal when it was first offered at an average age of one month (8). Harris and Chan reported that only 22 of 383 mothers indicated problems with the introduction of cereal, including dislike or refusal, stomach ache, loose stools and constipation (9). Strained fruits are consistently reported to be well liked by all infants; applesauce and bananas are the favorites.' Strained vegetables as a group are also accepted; yellow vegetables are reported to be favorites, while beets and spinach are often refused. More problems have been reported with acceptance of meat than other infant foods. Fifty percent of 383 infants were reported by their mothers to refuse or spit out meat of any kind. Beef and chicken were the best accepted (9). Infants at birth appear able to distinguish solutions of sugar water from water and consume greater amounts of sugarsweetened solutions. This fact may account for the preference of many infants for fruit. They are indifferent to solutions of citric acid, urea or sodium chloride (10). The addition of salt does not appear to influence food acceptance by infants. Fomon and associates found that foure and seven-month-old infants consumed equivalent amounts of salted or unsalted semisolid foods (11). Allergy. Guthrie reported that 10% of the parents of infants she studied volunteered information that physicians had advised eliminating some or all semisolid foods to alleviate problems with food allergies (12). It has been suggested that infants of parents who have allergic responses to food not be offered the more allergenic foods, such as milk, eggs, or wheat, for the fIrst
A number of criteria . .. are quite arbitrary and ignore individual differences among infants and patterns of physical growth.
April-June 1977
Vol. 9
No.2
Journal of Nutrition Education
57
six to nine months of life. Results of the approach have, however, not indicated it to be a useful routine procedure (13).
Weight Gain and Later Obesity There is current concern that excessive weight gain in infancy may be an important factor in the etiology of later obesity. It has been hypothesized that the early addition of semisolid foods results in excessive energy intakes and weight gains during that period. Charney and associates found that infants who attained the 90th percentile in weight during the fIrst six months of life were 2.6 times more likely to be overweight or obese as adults than those who were average or light weight (14). They suggested that absolute weight gain, not the rate of weight gain, was the critical factor. The risk of later obesity was found to be closely linked to body weight and independent of body length. British studies have also indicated that weight gain ininfancy was important to future obesity. Eid found that 7.4070 of infants who were growing rapidly (weight above the 90th percentile) at six weeks of age, and 16.7% of those who had experienced excessive weight gain by six months, were obese at six to eight years of age. An additional 18.5% of those with rapid weight gain by six weeks and 26.7% of those who had experienced excessive weight gains by six months were overweight in the early school years (15). Shukla and associates in a cross sectional study of intakes of infants found that those who consumed semisolid foods during the first three months consumed an average of 240 kcalories per day more than the recommended energy intake, while infants who received .only a liquid intake consumed an average of 40 kcalories per day more than the recommended intake (12). Since rapid changes in infants' energy intakes occur in the fmt three months of life, total energy intakes increasing as calorie intakes per kilogram of body weight
58
Journal of Nutrition Education
Vol.9
No.2
April-June 1977
Normal infants can be well nourished and grow appropriately, consuming a variety of milks, with or without the addition of semisolid foods. are decreasing, the data are difficult to evaluate. No comparisons were made as to the kcall kg I day for infants receiving semisolid foods versus those receiving only a milk diet. Data, however, indicated that overnutrition during the first three months of life led to increased levels of body weight maintained throughout the fIrSt year in the population studies. Guthrie found the early introduction of semisolid foods to infants significantly increased intakes of iron and thiamin in the fIrSt seven weeks. After this age, all infants studied were consuming semisolid foods, and no differences were noted in nutrient intakes. Since there were no differences noted in energy intakes of infants studied, it was concluded that those who consumed semisolid foods had reduced their milk consumption (16).
Studies by Fomon and associates with formula-fed infants have indicated that during the first 41 days of life, volume is the determining factor in the infant's intake (17, 18). Infants fed calorically concentrated formula during that time reduced their volume of intake but consumed more calories than did those who ingested formulas of normal caloric concentration. After the fIrSt six weeks of life, the calorie intakes of infants fed formulas of concentrated, dilute or normal calorie concentration
were similar. Female infants who had been fed formula concentrated to 30 kcal! oz during the study period were heavier for their length at 111 days than were those fed a more dilute formula which contained 16.5 kcal/oz., even though average calorie intakes for the Ill-day period were comparable for both groups. It is reasonable to hypothesize from these studies that the caloric concentration of semisolid foods offered to infants during the first six weeks of life can increase or decrease energy intakes. Cereal mixed with milk and strained fruits, often the first semisolid foods fed to infants, are calorically concentrated compared to milk, while strained vegetables and vegetable/meat mixtures generally added after the 41st day are calorically more dilute. Many have hypothesized that infants who are fed only breast milk consume fewer calories and grow less rapidly than those who are bottle fed because parents are unaware of volumes consumed and feel no compulsion to have bottles and/or jars emptied. However, will lack of knowledge of intake by parents achieve the desired result? Infants eventually are offered semisolid or table foods. If parents are not well prepared to recognize satiation in their children, overfeeding has only been delayed.
Recommendations Wide ranges of nutrient and energy intakes of normal, healthy infants have been noted by many researchers. Normal infants can be well nourished and grow appropriately, consuming a variety of milks, with or without the addition of semisolid foods, a fact observed by many clinicians. Breast-fed infants who receive iron, appropriate vitamins, and flouride supplements, and are growing as expected, will receive all the energy and nutrients they need. Appropriately supplemented formula-fed infants can be considered to be in the same situation. No nutritional or developmental advantage will be derived from the introduction of semisolid foods prior to the time infants are developmentally four to six months of age. In fact, the introduction of amounts of semisolid foods which appreciably reduce an infant's intake of milk can have serious nutritional consequences. Parents eager to achieve an infant's acceptance of milk or semisolid foods can reinforce excessive energy intakes and thereby pattern excessive food intakes which may lead to overweight and obesity. It is important to introduce food sources of iron and vitamin C before these nutrients are deleted from the diet when the transition is made from breast or bottle feeding to fluid milk. The introduction of semisolid foods when the mature sucking pattern becomes evident provides sensory stimuli and experiences which desensitize the gag reflex. It is important for infants to have these experiences by the developmental age of six months. When semisolid foods are introduced, attention must be paid to the quantity consumed and its effect on the infant's total energy and nutrient intake and rate of growth. Recommendations to increase or decrease the quantity or type of semisolid foods may need to be made for individual infants. Parents decide what their infants will be offered. They need information on which to base that decision, not arbitrary instructions on what and when to feed their infants or judgments made when they "do their own thing." Instructions should be educational in nature and provide help, not only in the selection of milks and foods for infants, but also with individual parents' adaptation to their infants and recognition of their infants' cues of hunger and satiation. 0
References I 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18
Fomon, S. J., What are infants fed in the United States? Pediatrics, 56:350,1975. Beal, V. A., Termination of night feeding in infancy, J. Pediat., 75:690,1969. Grunwaldt, E., T. Bates and D. Guthrie, The onset of sleeping through the night in infancy, Pediatrics, 26:667, 1960. Bakwin, H., Infant feeding, Am. J. Clin. NutL, 1:349, 1953. Stevenson, S. S., Some thoughts on the present status of infant feeding in the United States, Q. Rev. PediaL, 14:162, 1959. Mayer, H. F., Infant Foods and Feeding Practice, Charles C. Thomas, Springfield, Ill., 1960, p. 183. Gesell, A. and F. L. Ilg, Feeding Behavior of Infants, J. B. Lippincott Co., Philadelphia, 1937. Beal, V. A., On the acceptance of solid foods and other food patterns of infants and children, Pediatrics, 20:448, 1957. Harris, L. E. and J. C. M. Chan, Infant feeding practices, Am. J. Dis. Child., 117:483, 1969. Maller, O. and J. A. Desor, Effect of taste on ingestion by human newborns, in Oral Sensation and Perception, Bosma, J. F., Ed., DHEW publication No. (NIH) 73-546, Department of Health, Education and Welfare, Bethesda, Md., 1973. Fomon, S. J., L. N. Thomas and L. J. Filer, Acceptance of unsalted strained foods by normal infants, J. Pediat., 76:242, 1970. Shukla, A., H. A. Forsyth, C. M. Anderson and A. Mafwah, Infantile overnutrition in the first year of life: A field study in Dudley, Worcestershire, Brit. Med. J., 4:507,1972. May, C. D., Food Allergy, in Infant Nutrition, Fomon, S. J., Ed., W. B. Saunders Co., Philadelphia, 1974, p. 435. Charney, E., H. C. Goodman, M. McBride, B. Lyon and R. Pratt, Childhood antecedents of adult obesity, New Eng. J. Med., 295:6, 1976. Eid, E. E., Follow-up study of physical growth of children who had excessive weight gain in the first six months of life, Brit. Med. J., 2:74,1970. Guthrie, H. A., Effect of early feeding of solid foods on nutrient intake of infants, Pediatrics, 38:879, 1966. Fomon, S. J., et ai, Influence of formula concentration on caloric intake and growth of normal infants, Acta Paediat. Scand., 64:172,1975. Fomon, S. J., et ai, Relationship between formula concentration and rate of growth of normal infants, J. NutL, 98:241, 1969.
April-June 1977
Vol. 9
No.2
Journal of Nutrition Education
59
P E
R S P E
Peggy Pipes Developmental readiness, rather than chronological age, is the important criterion. There is today a wide range of opinions as to the appropriate time for the introduction of semisolid foods to infants and the long-term effects of the early introduction of these foods. Fomon estimated in 1975 that 71110 of energy consumed by infants in the United States was derived from semisolid foods-e.g., cereals, strained meats, vegetables and fruits, eggs and other foods-in the fIrSt month of life and that percentage increased to nearly 30% at five to six months. Concurrently, table food consumption increased during the first six to nine months. After this, the percentage of energy derived from semisolid foods decreased while that from table food increased to 46% at one year (1). Many feel that the addition of semisolid foods to infants' diets in the fIrSt weeks and months of life may contribute to obesity in infancy and later life. Others are concerned about allergic reactions or that salt, sugar and other additives in commercially prepared infant foods may predispose susceptible individuals to hypertension and poor food habits. On the other hand, there are those with years of experience in counseling mothers of young infants who feel that the early introduction of semisolid foods is appropriate. Parents often introduce semisolid foods without professional advice. Many respond to suggestions of relatives, neighbors and friends, often feeding semisolid foods to their infants in the belief that early addition of these foods will encourage their infants to sleep through the night. However, several studies have shown that addition of semisolids does not influence the infant's sleep patterns and does not result in an uninterrupted nights sleep for the caregiver (2,3). A number of criteria have been used as a basis for recommending the addition of semisolid foods to the infant's diet, such as chronological age, volume of milk the infant consumes, the need for iron-containing foods and developmental readiness (4-6). Some, such as chronological age alone, are quite arbitrary and ignore individual differences among infants and patterns of physical growth.
Development of Feeding Behavior Neurological maturation during infancy causes changes in the manner by which the infant secures food from the nipple or spoon. The young infant obtains milk by a rhythmic suckle with an up and down movement of the tongue. Semisolid foods fed by spoon in the fIrst months of life are ingested with these same stroking movements, the tongue projecting as the spoon is withdrawn. Frequently food is expelled from the mouth. At approximately 16 weeks, a more mature sucking pattern develops with the tongue moving back and forth instead of the earlier up and down motions. Spoon feeding is then easier because the
THE A UTHOR is Assistant Chief, Nutrition Section, Child Development and Mental Retardation Center, also Lecturer, School of Home Economics, University of Washington, Seattle, WA 98195.
C T I V E
child can draw in the lower lip as the spoon is removed. Infants are thus better prepared to consume semisolid food at 16 to 18 weeks than they have been previously. Foods no longer have to be diluted to an almost liquid consistency to achieve their acceptance (7). Infant's acceptance of semisolid food. Cereal is consistently reported to be the fIrst food added to the infant's diet; rice cereal is commonly the fIrst cereal grain to be offered. Parents thin the cereal to an almost liquid consistency, which permits the infant to suckle the mixture. Beal reported that cereal was generally accepted without problems between two and one half and three months. However, 32% of 37 infants willingly accepted cereal when it was first offered at an average age of one month (8). Harris and Chan reported that only 22 of 383 mothers indicated problems with the introduction of cereal, including dislike or refusal, stomach ache, loose stools and constipation (9). Strained fruits are consistently reported to be well liked by all infants; applesauce and bananas are the favorites.' Strained vegetables as a group are also accepted; yellow vegetables are reported to be favorites, while beets and spinach are often refused. More problems have been reported with acceptance of meat than other infant foods. Fifty percent of 383 infants were reported by their mothers to refuse or spit out meat of any kind. Beef and chicken were the best accepted (9). Infants at birth appear able to distinguish solutions of sugar water from water and consume greater amounts of sugarsweetened solutions. This fact may account for the preference of many infants for fruit. They are indifferent to solutions of citric acid, urea or sodium chloride (10). The addition of salt does not appear to influence food acceptance by infants. Fomon and associates found that foure and seven-month-old infants consumed equivalent amounts of salted or unsalted semisolid foods (11). Allergy. Guthrie reported that 10% of the parents of infants she studied volunteered information that physicians had advised eliminating some or all semisolid foods to alleviate problems with food allergies (12). It has been suggested that infants of parents who have allergic responses to food not be offered the more allergenic foods, such as milk, eggs, or wheat, for the fIrst
A number of criteria . .. are quite arbitrary and ignore individual differences among infants and patterns of physical growth.
April-June 1977
Vol. 9
No.2
Journal of Nutrition Education
57
six to nine months of life. Results of the approach have, however, not indicated it to be a useful routine procedure (13).
Weight Gain and Later Obesity There is current concern that excessive weight gain in infancy may be an important factor in the etiology of later obesity. It has been hypothesized that the early addition of semisolid foods results in excessive energy intakes and weight gains during that period. Charney and associates found that infants who attained the 90th percentile in weight during the fIrst six months of life were 2.6 times more likely to be overweight or obese as adults than those who were average or light weight (14). They suggested that absolute weight gain, not the rate of weight gain, was the critical factor. The risk of later obesity was found to be closely linked to body weight and independent of body length. British studies have also indicated that weight gain ininfancy was important to future obesity. Eid found that 7.4070 of infants who were growing rapidly (weight above the 90th percentile) at six weeks of age, and 16.7% of those who had experienced excessive weight gain by six months, were obese at six to eight years of age. An additional 18.5% of those with rapid weight gain by six weeks and 26.7% of those who had experienced excessive weight gains by six months were overweight in the early school years (15). Shukla and associates in a cross sectional study of intakes of infants found that those who consumed semisolid foods during the first three months consumed an average of 240 kcalories per day more than the recommended energy intake, while infants who received .only a liquid intake consumed an average of 40 kcalories per day more than the recommended intake (12). Since rapid changes in infants' energy intakes occur in the fmt three months of life, total energy intakes increasing as calorie intakes per kilogram of body weight
58
Journal of Nutrition Education
Vol.9
No.2
April-June 1977
Normal infants can be well nourished and grow appropriately, consuming a variety of milks, with or without the addition of semisolid foods. are decreasing, the data are difficult to evaluate. No comparisons were made as to the kcall kg I day for infants receiving semisolid foods versus those receiving only a milk diet. Data, however, indicated that overnutrition during the first three months of life led to increased levels of body weight maintained throughout the fIrSt year in the population studies. Guthrie found the early introduction of semisolid foods to infants significantly increased intakes of iron and thiamin in the fIrSt seven weeks. After this age, all infants studied were consuming semisolid foods, and no differences were noted in nutrient intakes. Since there were no differences noted in energy intakes of infants studied, it was concluded that those who consumed semisolid foods had reduced their milk consumption (16).
Studies by Fomon and associates with formula-fed infants have indicated that during the first 41 days of life, volume is the determining factor in the infant's intake (17, 18). Infants fed calorically concentrated formula during that time reduced their volume of intake but consumed more calories than did those who ingested formulas of normal caloric concentration. After the fIrSt six weeks of life, the calorie intakes of infants fed formulas of concentrated, dilute or normal calorie concentration
were similar. Female infants who had been fed formula concentrated to 30 kcal! oz during the study period were heavier for their length at 111 days than were those fed a more dilute formula which contained 16.5 kcal/oz., even though average calorie intakes for the Ill-day period were comparable for both groups. It is reasonable to hypothesize from these studies that the caloric concentration of semisolid foods offered to infants during the first six weeks of life can increase or decrease energy intakes. Cereal mixed with milk and strained fruits, often the first semisolid foods fed to infants, are calorically concentrated compared to milk, while strained vegetables and vegetable/meat mixtures generally added after the 41st day are calorically more dilute. Many have hypothesized that infants who are fed only breast milk consume fewer calories and grow less rapidly than those who are bottle fed because parents are unaware of volumes consumed and feel no compulsion to have bottles and/or jars emptied. However, will lack of knowledge of intake by parents achieve the desired result? Infants eventually are offered semisolid or table foods. If parents are not well prepared to recognize satiation in their children, overfeeding has only been delayed.
Recommendations Wide ranges of nutrient and energy intakes of normal, healthy infants have been noted by many researchers. Normal infants can be well nourished and grow appropriately, consuming a variety of milks, with or without the addition of semisolid foods, a fact observed by many clinicians. Breast-fed infants who receive iron, appropriate vitamins, and flouride supplements, and are growing as expected, will receive all the energy and nutrients they need. Appropriately supplemented formula-fed infants can be considered to be in the same situation. No nutritional or developmental advantage will be derived from the introduction of semisolid foods prior to the time infants are developmentally four to six months of age. In fact, the introduction of amounts of semisolid foods which appreciably reduce an infant's intake of milk can have serious nutritional consequences. Parents eager to achieve an infant's acceptance of milk or semisolid foods can reinforce excessive energy intakes and thereby pattern excessive food intakes which may lead to overweight and obesity. It is important to introduce food sources of iron and vitamin C before these nutrients are deleted from the diet when the transition is made from breast or bottle feeding to fluid milk. The introduction of semisolid foods when the mature sucking pattern becomes evident provides sensory stimuli and experiences which desensitize the gag reflex. It is important for infants to have these experiences by the developmental age of six months. When semisolid foods are introduced, attention must be paid to the quantity consumed and its effect on the infant's total energy and nutrient intake and rate of growth. Recommendations to increase or decrease the quantity or type of semisolid foods may need to be made for individual infants. Parents decide what their infants will be offered. They need information on which to base that decision, not arbitrary instructions on what and when to feed their infants or judgments made when they "do their own thing." Instructions should be educational in nature and provide help, not only in the selection of milks and foods for infants, but also with individual parents' adaptation to their infants and recognition of their infants' cues of hunger and satiation. 0
References I 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18
Fomon, S. J., What are infants fed in the United States? Pediatrics, 56:350,1975. Beal, V. A., Termination of night feeding in infancy, J. Pediat., 75:690,1969. Grunwaldt, E., T. Bates and D. Guthrie, The onset of sleeping through the night in infancy, Pediatrics, 26:667, 1960. Bakwin, H., Infant feeding, Am. J. Clin. NutL, 1:349, 1953. Stevenson, S. S., Some thoughts on the present status of infant feeding in the United States, Q. Rev. PediaL, 14:162, 1959. Mayer, H. F., Infant Foods and Feeding Practice, Charles C. Thomas, Springfield, Ill., 1960, p. 183. Gesell, A. and F. L. Ilg, Feeding Behavior of Infants, J. B. Lippincott Co., Philadelphia, 1937. Beal, V. A., On the acceptance of solid foods and other food patterns of infants and children, Pediatrics, 20:448, 1957. Harris, L. E. and J. C. M. Chan, Infant feeding practices, Am. J. Dis. Child., 117:483, 1969. Maller, O. and J. A. Desor, Effect of taste on ingestion by human newborns, in Oral Sensation and Perception, Bosma, J. F., Ed., DHEW publication No. (NIH) 73-546, Department of Health, Education and Welfare, Bethesda, Md., 1973. Fomon, S. J., L. N. Thomas and L. J. Filer, Acceptance of unsalted strained foods by normal infants, J. Pediat., 76:242, 1970. Shukla, A., H. A. Forsyth, C. M. Anderson and A. Mafwah, Infantile overnutrition in the first year of life: A field study in Dudley, Worcestershire, Brit. Med. J., 4:507,1972. May, C. D., Food Allergy, in Infant Nutrition, Fomon, S. J., Ed., W. B. Saunders Co., Philadelphia, 1974, p. 435. Charney, E., H. C. Goodman, M. McBride, B. Lyon and R. Pratt, Childhood antecedents of adult obesity, New Eng. J. Med., 295:6, 1976. Eid, E. E., Follow-up study of physical growth of children who had excessive weight gain in the first six months of life, Brit. Med. J., 2:74,1970. Guthrie, H. A., Effect of early feeding of solid foods on nutrient intake of infants, Pediatrics, 38:879, 1966. Fomon, S. J., et ai, Influence of formula concentration on caloric intake and growth of normal infants, Acta Paediat. Scand., 64:172,1975. Fomon, S. J., et ai, Relationship between formula concentration and rate of growth of normal infants, J. NutL, 98:241, 1969.
April-June 1977
Vol. 9
No.2
Journal of Nutrition Education
59