ENERGY INTAKES OF CHILDREN BY AGE GROUPS  

(Prepared by FAO)

1. The First and Second FAO Committees proposed an evaluation of the calorie requirements of reference man and woman based on a factorial analysis, taking into consideration four variables: Physical activity, body mass, age, and climate. Estimations of children's requirements, however, have by and large taken into account actual intake as revealed by individual surveys carried out on children of different ages in a certain number of countries. It would appear important to examine data from surveys made in developed and developing countries so as to compare these with requirements as determined by the FAO Group of Experts. The comparison seems justified in that the committee did not feel it necessary to propose adjustments for height or weight of children differing from adjustments made for the adult reference group.

2. The adjusted data in Table 1 were established by Leitch and Widdowson. They were drawn from the two most important surveys available. The survey made in Great Britain (Widdowson, 1939) covers 916 girls and boys between the ages of 1 and 18. The Iowa survey (Eppright, Sidwell and Swanson, 1954), considers 1188 children and adolescents between the ages of 6 and 18 (1) (2). Intake levels, according to the authors, "were found to be in such excellent agreement that a smooth line could be drawn to fit both." (3)

Table 1

Calorie Intake of Children and Adolescents in Great Britain and the United States (Iowa) compared to FAO Requirements

3. A longitudinal study on 78 boys and 82 girls between the ages of 1 and 6 was carried out by the Harvard School of Public Health (Table 2) (4).

Table 2
Mean daily Calorie Intake per Person with individual Variations

4. The level of intake is slightly below that of previous data. No noticeable differences in intake were noted between boys and girls before the age of 5.

5. These results led the Second FAO Committee on Calorie Requirements to raise the calorie requirements of children in age groups 1 - 3, 4 - 6 and 7 - 9 by 100 calories with relation to the estimates of the First Committee and to lower the requirements of boys in age group 16 - 19 by 200 calories (5) and (6).

6. A dietary survey by the weighing method over a 7-day period and covering 9000 families was carried out by Euratom/AEC in 1963/65 in 11 regions of the European Community (7). The authors worked out a mathematical model based on per family intake which made possible an estimate of intake by age groups in each region. The values in Table 3 were determined year by year from smoothed curves using a polynominal model and represent mean calorie intake by age groups. The number of children surveyed ranges from 2132 to 3581 in the different age groups and represents a total of 16 247 children and adolescents.

7. It may be noted that mean intake by age groups varies rather noticeably by regions. In the same way, calorie intakes within the groups deviate quite markedly from the mean. This concurs with observations made during the British and American surveys which show "enormous differences between individuals", sometimes ranging from simple to double, as well as marked variations from one day to the next for the same individual. Means by age groups (boys and girls) determined for all of the 11 regions in the survey were plotted on the graph. The slope of the curve is slightly flattened with relation to that of the American and English children. Indeed, over-intake among the younger age groups and underintake among the adolescents is observed. With regard to proposed FAO requirements, age groups between 13 and 20 years show an average calorie "deficit" of 10 percent, which seems inadmissible. Nevertheless, the lack of anthropometric data makes it impossible to determine to what extent these differences may be explained by differences of weight and stature.

8. If the concept of requirements based on the intake of individuals in good health is accepted, there might be a temptation - in view of these data - to make a slight increase in requirements for children between 1 and 6 and once again downgrade the requirements for boys between 13 and 20 years. At any rate it is possible that the application of FAO requirements to the populations of the developing countries may not lead to overestimations of energy expended. In fact, the adolescents - or at least most of them - in these countries engage in agricultural activities which may perhaps require a greater expenditure of calories than that of children living in mechanised civilizations.

9. Table 4 presents the results of surveys carried out in developing countries. These surveys dealt with a limited number of individuals and half of them were concerned only with the intake of pre-school children (8), (9), (10), (11), (12), (13), (14), (15), (16). It is difficult to make comparisons from one survey to another as they were determined on varying age groups which usually differ from those proposed by the FAO Committee. In order to facilitate the interpretation of Table 4, calorie intakes are shown in a rectangle whose height corresponds to the age groups surveyed. When several figures appear in the same rectangle, they correspond to different population groups in the country under consideration.

Table 3

Estimated Intake by Age Groups in 11 Regions of the European Community
(Average calories per person and per day) (7)

Table 4

FAO Calorie Requirements and Mean Energy Intake by Sex and Age Groups
according to Individual Surveys

10. These data also appear on the graph as points. Intake in each survey and for all age groups is clearly below required levels. It was possible in some surveys to trace mean intake curves of the various age groups: India (21), New Guinea (19), Basutoland (17) and Puerto Rico (18). The slope of these curves is comparable to that obtained on European and American children. But they are clearly displaced throughout their length towards the base line and very marked calorie deficiencies, with relation to FAO requirements, are observed. It may be said roughly that about 50 percent of the requirement is met between 1 - 3 years of age, 70 percent from ages 4 - 6, 65 percent between 7 and 12 and less than 60 percent between the ages of 13 and 15.

11. Is this deficit a real one? Or is it partially due to an overestimation of requirements? The answer to this question could only have been provided had clinical and anthropometric studies been made of the same sampling of children and had reliable data on the "normal" height and weight of children in the country under consideration been available.

12. The Puerto Rican survey, lasting one day, was carried out by the weighing method and covered 81 children ... the authors concluded that calorie intake was low. In comparison with U.S. and Puerto Rican standards, the weight and height of the group examined were found to fall below the norm: "The mean per cent standard weight shows that moderate, 10 to 20 percent, underweight was the rule from pre-school age to adolescence. Although adolescents were under the expected weight average for their age, their weight for attained height was very satisfactory." (18).

13. In Basutoland (Lesotho), 112 children were studied for from 3 to 7 days by the weighing method (17). Dietary intakes were judged by the author to be deficient in all nutriments with relation to INCAP requirements. Antropometric measurements made on a much larger group (3350 children) than in the above survey showed that 62 to 85 percent of children and adolescents, according to age groups, are underweight - a weight deficit of over 10 percent when compared with INCAP standards determined on well-nourished children. In the same way, these standards when used in Guatemala, showed that almost all pre-school children in the survey "fell below the sixteenth percentile in weight and more than one standard deviation below the mean in height." (10).

14. Twenty-three children in the Chimbu region of New Guinea were surveyed over a six-day period by the weighing method (19). A larger sampling of children's weights (776 children) showed these to be slightly below the weights of Bastuoland children (Table 5). It is therefore quite probable that the children in the above survey are also markedly underweight.

15. The Nigerian survey covered 108 rural children in two age groups. With respect to American children (standards Stuart and Meredith), children between the ages of 4 and 6 have a mean weight deficit of 2.5 kgs, and the 10 to 12 year olds are 5 kgs. underweight. They are also smaller. Nicol feels that "in determining the height and weight of the children a greater part is played by the intake of calories than by the amount of protein in the diet, provided that the deficiency of protein, quantitative and qualitative, is not severe." (22).

16. In India, the survey, which was carried out by interview, covered 177 children from poor families in the southern part of India. There are no data on the heights and weights of the children interviewed (21).

Table 5

Average Weight in kgs by Age and Sex

* Values determined on graph to coincide with FAO age groups (point of curve corresponding to mid-period of age group under consideration).

Table 6

Calorie Intake by Sex and Age
According to kg of Body Weight

* Values determined on graph to coincide with FAO age groups (point of curve corresponding to mid-period of age group under consideration).

17. The average weights of children by age groups are quite comparable from one survey to the other (Table 5) despite the fact that the surveys deal with very different racial groups. With respect to the weight curve of English children, weight retardation is very marked and corresponds clearly to an age group. Thus a child in Basutoland, Puerto Rico or New Guinea does not attain before the age of 10 or 12 the weight of an 7 to 9 year old English child.

18. The chart shows that calorie intake in these countries is 30 to 50 percent, according to age groups, below that of Europe or America. When intake is expressed in terms of kgs of body weight the gap narrows (Table 6). Seen in this light, the intake of Puerto Rican children, according to age groupings, is only 20 to 28 percent below that of British children. Whatever may be the country of origin of the survey, calorie intake per kg of body weight diminishes regularly with age and at adulthood falls to 50 percent (boys) and 40 percent (girls) of what it was between the ages of 1 and 3.

19. There is a temptation to attribute weight (and statural) retardations to calorie deficiency and consequently to nutritional deficiency. There is, however, no scientific evidence demonstrating diet as the sole determining factor since it is not possible to determine what share to assign to hereditary factors and to sanitary conditions.

20. Given the fact that the height and weight of adults in these countries differ from that of the reference adult, it would appear sensible to conclude that adjustments should be made for children and adolescents with respect to the "ideal" weight - which does not necessarily correspond to that of European children. The Second Committee on Protein Requirements has proposed adjustments based on adult weights for 16 to 19 year old adolescents (6). This could be extended to other age groups. One might conceive of a series of growth curves which would produce a variety of reference men and women from which weight by age groups might be derived by interpolation. Calorie as well as protein requirements would then be expressed per kg of body weight.

Recommendations

21. Given the lack of data at the present time, it would appear urgent that dietary surveys be made on children and adolescents. These surveys should be carried out in different ecological zones so that different diet patterns may be studied. At least 500 children of each sex should be covered by the surveys, and there should be equal distribution into age groups. It is imperative that age groups should include just one year in each group in order to avoid errors of interpolation and facilitate comparisons. The survey should be matched by a clinical survey and include multiple anthropometric data, measurements of energy expenditure, so that correlations may be drawn between intake levels, physical activity, and nutritional status.

Bibliography

(1) Widdowson, E.M. A Study of Individual Children's Diets. Med. Res. Council Report No. 257. HSO 1947.

(2) Eppright, E.S., Sidwell, V. D. and Swanson, P. P. Nutritive Value of the Diets of Iowa School Children. J. Nutr. Vol. 54, pp 371-388. 1954.

(3) Leitch, I. and Widdowson, E.M. Energy Needs of Boys and Girls. Memo to FAO 1956.

(4) Burke, B.S. Unpublished Data in Mayer J. Working Paper No. 7. FAO 1956.

(5) FAO. Calorie Requirements. Report of the Committee on Calorie Requirements. FAO Nutritional Studies No. 5. 1950.

(6) FAO. Calorie Requirements. Report of the Second Committee on Calorie Requirements. FAO Nutritional Studies No. 15. 1957.

(7) Cresta, M., Ledermann, S., Garnier, A., Lombardo, E. and Lacourly, G. Détermination des régimes alimentaires des populations de 11 régions de la Communauté Européenne en vue de l'étude des niveaux de contamination radioactive. Report EUR 4218 F, Euratom CEA 1969.

(8) Flores, Marina; Menchu, Maria Teresa; Lara, Marta Yolanda y Guzman, M.A. Relación entre la ingesta de calorias y nutrientes en prescolares y la disponibilidad de alimentos en la familia. Archivos Latino Americanos de Nutrición. Vol. 20, No. 1, 1970.

(9) Flores, Marina & Garcia, Berta. The Nutritional Status of Children of pre-school Age in the Guatemalan Community of Amatitlán. 1. Brit. J. Nutr. 14, pp 207-215. 1960.

(10) Béhar, M., Arroyave, G., Flores, Marina and Scrimshaw, N.S. The Nutritional Status of Children of pre-school Age in the Guatemalan Community of Amatitlán. 2. Brit. J. Nutr. 14, pp 217 - 230. 1960.

(11) Hueneman, R.L., Bruch, H.A., Scholes, R.T. Investigación alimenticia en el area de Montero Bolivia. Report SCISP 1955.

(12) Encuesta clinico nutricional concepción tarija. Informe Ministerio de Salud Publica. La Paz. 1969.

(13) Sotelo, L.V. y col. Resultado de las encuestas nutricionales: Santiago de Llallagua y San Benito. Informe Dept. Nacional Nutr. No. 5-67. La Paz. 1967.

(14) Fox, H.C., Campbell, V.S. and Morris, J.C. The Dietary and Nutritional Status of Jamaican Infants and Toddlers. Bull. Sc. Research Council. Vol. 8 No. 2-4, pages 33-51. 1968.

(15) Pérez Hidalgo, C., Chávez, A., Martinez, C. Metodologia simplificada de encuestas nutricionales. Salud Publica de Mexico. Vol. XI No. 2 Mexico 1969.

(16) Davey, P.L.H. The Nutrition of Children aged one to four Years. Rep. mimeo. National Food and Nutr. Board. Accra 1961.

(17) Muñoz, J.A., Anderson, M.M. Report on a Nutrition Survey in Basutoland from 1956 to 1960. Rep. mimeo. WHO Reg. Off. Africa. 1962.

(18) Fernández, N.A., Burgos, J.C., Plough, I.C., Roberts, L.J., and Asenjo, C.F. Nutritional Status of People in Isolated Areas of Puerto Rico. Am. J. Cl. Nutr. Vol. 19, No. 4, pages 269-284. 1966.

(19) Venkatachalam, P.S. A Study of the Diet, Nutrition and Health of the People of the Chimbu Area, New Guinea Highlands. Monograph No. 4. Dept. Pub. Health, Territory of Papua and New Guinea. 1962.

(20) Malcom, Sheila, H. A Study of Food Intake in two Areas of New Guinea. Report South Pacific Commission. Noumea 1958.

(21) Bhavani Belavady, Swaran Pasricha and Kalpakam Shankar. Studies on Lactation and Dietary Habits of the Nilgiri Hill Tribes. Ind. J. Med. Res. Vol. 47, No. 2. 1959.

(22) Nicol, B.M. The Nutrition of Nigerian Children with Particular Reference to their Energy Requirements. Br. J. Nutr. Vol. 10, pp 181-197. 1956.