Poultry see Meat Poultry and Meat Products

first 8 weeks of life, and the fetal period, which lasts from the 9th week of gestation until term. During the latter period the fetus is entirely dependent on the placenta for its supply of nutrients. The fetus has an absolute requirement for the same essential nutrients as the adult but the adequacy of supply is particularly critical during in utero life when all the structures of the body are being established. In addition, because of the particularly high demand for some strictly nonessential nutrients these may be considered as 'conditionally essential' if the rate of utilization exceeds the fetal capacity for de novo synthesis.

The placenta has to maintain the supply of all nutrients at a rate adequate to allow unrestricted fetal growth. It also has to provide an appropriate mix of nutrients to meet the needs of the fetus at the different stages of pregnancy. For example, in the first two-thirds of pregnancy the fetus deposits mainly protein, while in late gestation fat takes over as the dominant form of deposition (Figure 1).

The availability of individual nutrients to the fetus depends not only on the maternal dietary intake but also on the function of the placenta and the many physiological and biochemical adaptations that occur during pregnancy (Figure 2). An understanding of placental function and its interaction with diet is essential to the setting of appropriate dietary guidelines for pregnancy.

ra ffi ra

-1—'—i—'—i—'—i—'—i—'—i— ■ • ■ 0 Surface area

-1—'—i—'—i—'—i—'—i—'—i— ■ • ■ 0 Surface area

12 16 20 24 28 32 36 40 Gestational age (weeks)

12 16 20 24 28 32 36 40 Gestational age (weeks)

12 16 20 24 28 32 36 40 Gestational age (weeks)

12 16 20 24 28 32 36 40 Gestational age (weeks)

Quick Permanent Weight Loss

Quick Permanent Weight Loss

A Step By Step Guide To Fast Fat Loss. Do you ever feel like getting rid of the extra weight of your body? If you do, it‟s quite normal because

Get My Free Ebook


Post a comment