The topic ‘Protein and Energy Requirements in Infancy and Childhood’ was
chosen for the 58th Nestlé Nutrition Pediatric Workshop, which took place in
November 2005 in Ho Chi Minh City, Viet Nam. In 1993 the 33rd Nestlé
Nutrition Workshop on ‘Protein Metabolism during Infancy’, chaired by Prof.
Niels Raïhä, was held in South Africa. In this workshop, Prof. Raïhä
introduced a new concept in terms of protein requirements, proposing a
reduction in the protein level of infant formulas in order to come closer to that
of human milk.
Some 30 years ago, Günter Dörner stated that the concentrations of hormones,
metabolites and neurotransmitters during critical periods of early development will
program disease risk in human adulthood, a concept that since has received enormous
scientific support and broad attention. Evidence has also accumulated showing that
early nutrition programs later obesity risk.
The energy requirements of infants and children are defined as the amount of
food energy needed to balance total energy expenditure (TEE) at a desirable level of
physical activity, and to support optimal growth and development. New TEE data
from doubly labeled water and heart rate monitoring are available to derive the
energy requirements. Compared with the 1985 FAO/WHO/UNU recommendations,
the 2004 FAO/WHO/UNU and 2002 IOM recommendations are ~12–20% lower during
infancy. The 2004 FAO/WHO/UNU recommendations are on average 18% lower for
boys and 20% lower for girls 7 years of age, and 12% lower for boys and 5% lower
for girls 7–11 years of age. From 12 to 18 years of age, the requirements are 12%
higher for boys and girls. The 2002 IOM recommendations are 8% lower for children
7 years of age, 2% lower for children 7–11 years of age, and 8% higher for children
12–18 years of age.
During the last 35 years there have been various published assessments of human
protein needs, including those of infants and children. Most recently, the Institute of
Medicine of the US National Academies has published its report on Dietary Reference
Intakes (DRI) for Macronutrients, and WHO/FAO/UNU have convened a new Expert
Consultation, which is due to be published soon.
Growth and nutrition during infancy are being viewed with renewed interest
because of the possibility that they may be linked to cardiovascular and metabolic
health in later life. Of particular interest are differences between breast- and formulafed
infants with regard to nutrient intake and growth because breastfeeding has been
shown to be associated with a reduced risk of obesity in later life. During the first 6–8
weeks of life there is little difference in growth (gain in weight and length) between
breast- and formula-fed infants. However, from about 2 months of age to the end of the
first year of life formula-fed infants gain weight and length more rapidly than breast-fed
Knowledge of changes in body composition is of great potential benefit to the understanding
of the nutritional needs and functional outcome of nutritional management for
both healthy and sick infants. This review evaluates the different methods presently
available to evaluate whole-body composition analysis based on different models, i.e. 2,
3, or more compartments.
Nutrient reference values provide guidance for maintaining and enhancing health
via standard setting and development of nutritionally improved products to decrease
the risk of disease. Since 1941, the Food and Nutrition Board (FNB) of the National
Academy of Sciences in the United States has developed and periodically revised recommendations
for nutrients; the last (10th) edition of the Recommended Dietary
Allowances (RDA) was released in 1989.
The portal-drained viscera (stomach, intestine, pancreas and spleen) have a much
higher rate of both energy expenditure and protein synthesis than can be estimated on
the basis of their weight. A high utilization rate of dietary nutrients by the portal-drained
viscera might result in a low systemic availability which determines whole-body growth.
From studies in our multiple catheterized piglet model, we conclude that more than half
of the dietary protein intake is utilized within the portal-drained viscera and that amino
acids are a major fuel source for the visceral organs.
Nitrogen balances have been conducted in preterm infants, preschool children, and
6- to 10-year-old children to determine dietary indispensable amino acid. A recent
review concluded that the data, being sufficiently uncertain, could not be used as the
basis for defining amino acid requirements in infants and children. Therefore, it was
decided to use a factorial approach (basal plus growth).
Among other nutrients of breast milk, the amino acid pattern is considered normative
throughout infancy. Exclusive breastfeeding by a healthy mother should be the
standard from birth to 6 months. During the breastfeeding period the protein intake is
low in the human being compared too many other animals.
Food intake is regulated in both the short- and long-term by a complex physiological
system that involves neuroendocrine pathways that are both distinct and overlapping.
The underlying causes and mechanisms of the dysregulation of food intake in
obesity is poorly understood; however, it is clear that dietary components interact
with the physiological determinants of food intake and can cause profound alterations
during the development of control mechanisms.
The possible role of early dietary habits as the origin of later consequences on
health has raised questions on the optimal macronutrient intakes of the growing
infant. Infants and toddlers in developed countries usually show a high dietary protein:
energy ratio during the complementary feeding period, averaging 2.5–3, because
of the protein density of solid weaning foods and the low percentage of mothers still
breastfeeding beyond the first 6 months of life.
In 2001, a WHO Expert Consultation concluded that waiting until 6 months to
introduce complementary foods to breastfed infants confers several benefits for both
infants and mothers. Nonetheless, there is still controversy about this issue. In developing
countries, the reduced risk of infant gastrointestinal illness and increased duration
of maternal lactational amenorrhea associated with exclusive breastfeeding for 6
months make the benefit-risk ratio of this recommendation highly favorable. In industrialized
countries, the case is less clear-cut, but the benefit-risk ratio is also likely to
be favorable with regard to infant infectious morbidity, motor development and maternal
weight loss postpartum.
Thirty years ago, protein deficiency was perceived to be the major nutritional problem
of children in developing countries. Later on increasing the energy intake of
young children during the complementary feeding period became a priority. Early
studies on the pathophysiology of malnutrition are now turned into strategic and practical
consequences for the prevention and treatment of severe malnutrition, four of
which are presented. (1) Almost half of the deaths worldwide are due to being underweight.
Nowadays, well-defined preventive and curative interventions have been identified.
The development of infant formula with optimized protein quality and quantity has
been, and still is, the subject of intense investigation. A better understanding of the
protein composition of breast milk and infant needs in association with technological
breakthroughs in cow’s milk fractionation, has led to the development of infant formulas
with a protein content that is closer to that of human milk.
Human milk provides proteins that benefit newborn infants. They not only provide
amino acids, but also facilitate the absorption of nutrients, stimulate growth and
development of the intestine, modulate immune function, and aid in the digestion of
other nutrients. Breastfed infants have a lower prevalence of infections than formulafed
infants. Since many women in industrialized countries choose not to breastfeed,
and an increasing proportion of women in developing countries are advised not to
breastfeed because of the risk of HIV transmission, incorporation of recombinant
human milk proteins into infant foods is likely to be beneficial.
I would like first to thank you all for sharing your experiences and
exchanging knowledge; we all have benefited from it. We all shared the objectives
and the goal that we wish to further the lot of children in the world. To
that goal these exciting 3 days have enhanced our ability to carry out our
objectives. It is appropriate that we thank the sponsors who have brought us
together here, and that is the Nestlé Nutrition Institute, its director, Dr.
Ferdinand Haschke and Dr. Denis Barclay who have organized this meeting,
and we must also not forget Dr. Philippe Steenhout who conceived this conference
and organized it initially before he turned things over to Dr. Barclay
and we are grateful for all their efforts. We also express our gratitude to the
local organizers, Pierre Schaufelberger; we thank Vipapan Panitantum and
Montip Nagsevi and all the other staff of Nestlé Viet Nam for organizing this
so splendidly and for feeding us so excellently.