Cover Image
close this bookActivity, Energy Expenditure and Energy Requirements of Infants and Children (International Dietary Energy Consultative Group - IDECG, 1989, 412 pages)
close this folderThe desirable upper limits of energy intake in childhood: Short- and long-term consequences
View the document(introductory text...)
View the documentAbstract
View the document1. Introduction
View the document2. A conceptual approach to defining desirable intakes in infancy
View the document3. Childhood obesity and energy intake
View the document4. Individual susceptibility to obesity
Open this folder and view contents5. Desirable intakes in infancy
View the document6. Ambient temperature and diet-induced thermogenesis
View the document7. Should energy requirements be based on data for breast-fed children?
View the document8. The fat cell hypothesis
View the document9. The Dutch famine study: An early programming of adiposity?
View the document10. Links between childhood and adult obesity
View the document11. Experimental findings
View the document12. The effects of early feeding practices on the programming of metabolism
View the document13. Infant growth rates and long-term survival
View the document14. Conclusions
View the documentReferences
View the documentDiscussion (summarized by W. Dietz)

11. Experimental findings

It seems reasonable to consider some related studies on the long-term control of adiposity in primates. LEWIS et al. (1986) reported effects of feeding baboons three different formulations of milk for the first 4 months of life, i.e., until they were weaned (Table 1). Standardized volumes were fed, and the energy and other nutrient intakes were either increased or decreased by 40%. After normal feeding, underfeeding or overfeeding, all the infant baboons were weaned on to a freely available high-fat diet. Table 1 presents data recalculated to highlight the conclusion that adult adipocyte mass in all regions was affected by early dietary intake, but only in the external abdominal region was there a clear effect on adipocyte number. It would appear that hypercellularity did occur in infancy if the specific depots were still undeveloped at birth.

Table 1. Early feeding effects on adult baboon adipose tissue. Ratios of depot masses and adipocyte numbers in overfed and underfed animals

Fat depot

Male

Female


Total mass

Adipocyte numbers

Total mass

Adipocyte numbers

Omentum

2.0 *

0.9

5.7 *

0.8

Mesenteric

5.9 *

1.9

11.4 *

1.8

Perirenal

3.0

1.2

5.9 *

1.0

Posterior flank

5.7 *

2.5 *

24.3 *

3.5 *

Axillary

2.2

1.3

11.8 *

2.8

Popliteal

1.6

1.1

3.3 *

1.4

Recalculated from data by LEWIS et al. (1986) where baboons are fed milk formula for 16 weeks providing 94.5 kcal/100 g or 40.5 kcal/100 g. Total adipose triglyceride mass and cellularity in each depot were assessed at 5 years after ad libitum feeding on the same high-fat diet.

* p < 0.05

In baboons, most adipocyte regions had developed, as in man, in late foetal life, so only the groin, flank and mesenteric depots were poorly developed at birth. Female animals also seemed much more susceptible to the influence of early feeding, but whether this reflected sex-specific changes after weaning in intake or activity was unknown. By 1 year of age, animals fed differently in infancy were of similar weight, and this similarity was maintained in males through to adulthood. Marked differences in the weights of females only reappeared at almost 3 years of age implying a role for pubertal events in allowing obesity to be revealed once more.

These findings lend support to the proposition that different levels of food intake in early life can indeed have a marked influence on adult adiposity but this is unlikely to be mediated by the induction of new adipocytes. How the effect is achieved remains unclear. Since the experimental findings manipulated total nutrient intake and not just energy intake, it is by no means certain that differences in energy intake were responsible.