Theoretical Total Metabolic Costs of Pregnancy

Compared to many other mammals, humans have a relatively small and usually single infant, which develops during a long gestation period. The energy stress to the mother is therefore low per unit time. The 49 MJ of energy deposited as the products of conception represents only 4 or 5 days of food intake for the mother. Humans also differ from most other mammals because their large fat stores can help meet some of these costs. The theoretical total metabolic costs (i.e., due to extra tissue and increased metabolism) of pregnancy are approximately 335 MJ (80 000 kcal), or 1.25MJ/day (300kcal). This value does not make any allowance for changes (increases or decreases) in energy expended on physical activity. It is assumed that the majority of the energy costs of human pregnancy are met by behavioral adjustments in energy metabolism rather than increased energy intake. This assumption has formed the basis for energy intake recommendations, some of which are summarized in Table 3. It should be noted that the 1985 estimates used by WHO/FAO/UNU are under revision. Future recommendations may separate the obligatory costs (e.g., by fixed increments for basal metabolic rate (BMR) and tissue deposition) and differences in physical activity (based on PAL values).

How To Reduce Acne Scarring

How To Reduce Acne Scarring

Acne is a name that is famous in its own right, but for all of the wrong reasons. Most teenagers know, and dread, the very word, as it so prevalently wrecks havoc on their faces throughout their adolescent years.

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