Recommendations

The 1985 FAO/WHO/UNU recommendations for dietary energy intake of healthy infants seem too high based on reported measurements of energy intake or energy expenditure and estimates of the energy deposited for growth. Because observed energy intakes may not reflect desirable intakes, measurements of energy expenditure are preferred as the basis for estimating energy requirements. Estimated energy requirements of infants based on total energy expenditure and growth are 9-39% lower than the 1985 FAO/WHO/UNU recommendations and provide strong evidence that current estimates should be revised. However, confirmation of this observation will require expansion of the available database on total energy expenditure of healthy infants, in terms of sample size, age range and geographic distribution across the entire age range of infancy. Data are particularly scarce in the second 6 months of infancy. Estimated energy requirements should be consistent with the growth reference endorsed by WHO. To better define the energy deposited during growth, changes in body composition during infancy must be confirmed.

Given the relative uniformity of behavior, physical activity and growth of healthy infants from different geographic origins, estimates of energy requirements can be applied universally to healthy infants. It should be appreciated that energy requirements of infants are a function of age, gender, body size and feeding mode. Stipulation of estimated energy requirements by these factors will depend on the application.

More data must be sought on the energy expenditure of infants in populations at risk of high rates of infection and exposed to other environmental sources of stress to determine if energy requirements are altered under these circumstances. The energy needs for adequate catch-up growth also must be considered.

Table 6 Energy requirement estimated from total energy expenditure and energy cost of growth

	Total energy expenditure						Energy deposition
Age (months)	ALL (kcal/d)	BFa (kcal/d)	FFa (kcal/d)	ALL (kcal/d)	BFa (kcal/d)	FFa (kcal/d)	(kcal/d)	(kcal/kg/d)
Boys
0-1	248	228	268	65	61	68	113	26
1-2	320	300	340	67	64	70	113	26
2-3	389	368	409	70	67	73	136	24
3-4	454	434	474	72	69	76	90	14
4-5	516	495	536	75	72	78	62	9
5-6	574	553	594	78	74	81	49	6
6-9	684	664	705	83	80	86	28	3
9-12	843	822	863	91	87	94	19	2
Girls:
0-1	241	220	261	65	61	68	102	22.5
1-2	306	286	326	67	64	70	102	22.5
2-3	369	349	389	70	67	73	108	20
3-4	431	411	451	72	69	76	79	13
4-5	492	472	513	75	72	78	65	10
5-6	552	532	573	78	74	81	56	8
6-9	666	645	686	83	80	86	26	3
9-12	820	799	840	91	87	94	21	2

Energy requirement
Age (months)	BFa (kcal/d)	FFa (kcal/d)	ALL (kcal/kg/d)	BFa (kcal/kg/d)	FFa (kcal/kg/d)
Boys
0-1	341	381	91	87	94
1-2	413	453	93	90	96
2-3	504	545	94	91	97
3-4	524	564	86	83	90
4-5	557	598	84	81	87
5-6	602	643	84	80	87
6-9	692	733	86	83	89
9-12	841	882	93	89	96
Girls:
0-1	322	363	88	84	90
1-2	388	428	90	86	92
2-3	457	497	90	87	93
3-4	490	530	85	82	89
4-5	537	578	85	82	88
5-6	588	629	86	82	89
6-9	671	712	86	83	89
9-12	820	861	93	89	96

^a BF = breast-fed; FF = formula-fed infants.

FIGURE 6 Energy requirements if infants estimated from total energy expenditure and energy deposition (kcal/kg/d).

FIGURE 7 FAO/WHO/UNU energy requirements compared against requirements (1) based on energy intakes observed after 1980 and (2) total energy expenditure (TEE) and energy deposition during growth (kcal/d).

FIGURE 8 FAO/WHO/UNU energy requirements compared against requirements (1) based on energy intakes observed after 1980 and (2) total energy expenditure (TEE) and energy deposition during growth (kcal/kg/d).

Acknowledgements - I wish to thank Drs PSW Davies, Cambridge, UK; KG Dewey, University of California-Davis; KF Michaelsen, The Royal Veterinary and Agricultural University, Copenhagen,
Denmark; AM Prentice, Dunn Nutrition, Cambridge, UK; AS Ryan, Ross Laboratories, Columbus, Ohio, and JE Stuff, Children's Nutrition Research Center, Houston, Texas for their contribution of data used in this manuscript, as well as Dr C Garza, Cornell University, Ithaca, New York, for his thoughtful review. I would also like to thank I Tapper for manuscript preparation, and L Loddeke and R Klein for editorial review.

This work is a publication of the USDA/ARS Children's Nutrition Research Center, Department of Pediatrics Baylor College of Medicine and Texas Children's Hospital, Houston, TX. Funding has been provided from the U.S. Department of Agriculture, Agricultural Research Service under Cooperative Agreement No. 58-6250-1-003. The contents of this publication do not necessarily reflect the views or policies of the U.S. Department of Agriculture, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government.