The nutritional requirements differ to some extent during the different periods of life. Women of reproductive age have additional needs because of menstruation and, of course, during pregnancy and lactation. Babies and children have higher needs per unit weight than adults, mainly because they are growing. Older people are a vulnerable group, are exposed to greater risk of malnutrition than younger adults.
Deficiency diseases are prevalent in specific population groups. (The diseases are described and discussed in Part III.) This chapter discusses the various energy needs of people in various life stages.
Humans get energy from food and liquids they consume. The nutrient requirement of women of reproductive age (especially during pregnancy and breastfeeding), children and young adolescents, and older people are different from those of men between 15 and 60 years, so not everyone needs the same amount of food.
Women of reproductive age
Women of reproductive age have more nutritional needs than men adults. One reason is that blood loss during menstruation leads to a regular loss of iron and other nutrients, and that women are more prone than men to anemia (see Chapter 13). Moreover, in many developing countries women are much stronger than men. In rural areas, are usually very involved in agriculture and in urban areas, work long hours in factories and other places, at home, field or factory, still have much work to do at home including food preparation and childcare. Often the burden of collecting water and fuel falls on women. All this work increases the nutritional needs of energy and other nutrients.
Nutritional status of women before, during and after pregnancy contributes to their own welfare, but also to their children and other family members. The field of maternal nutrition focuses attention on women as mothers. Often focuses on nutritional status as it relates primarily to the welfare of children and their capacity to engender nurse, sustenance and care. The health and welfare of the mother as such have been relatively neglected. This is so, the field of maternal health and child emphasize providing services and care of women so that they can have successful pregnancies and lactation, also in the interest of the child, without caring much for the mother. The dual function of the women as mothers and productive workers is affected by poor diet and ill health, not just their own welfare but for the whole family. The excessive burden of work can lead to women with low food consumption at the edge of malnutrition.
A poor diet, infections and some common acute chronic, repeated pregnancy, lactation and an excessive burden of work, are factors that can contribute to serious physiological exhaustion and sometimes malnutrition. It has been suggested the term "maternal depletion syndrome." In many countries young women before the age of 20 are happy, healthy and attractive, but 10 or 15 years later, still young at the end of their thirties, are prematurely aged, exhausted, sick and discouraged. Often, young women cannot even reach the 20 years without having a first pregnancy. Figure 3 illustrates the months of pregnancy and lactation a woman in Kenya, not to represent the African mothers, it is not atypical.
During pregnancy the nutritional needs of women are higher than in other stages of life. The diet should provide all the necessary elements for growing the fertilized egg or ovum, becoming a viable fetus and then a baby to term (see Table 4). As the female feeds on itself also nourishes the growing fetus and placenta that binds to the fetus by the umbilical cord in utero. At the same time their breast tissue is prepared for breastfeeding.
During the first half of pregnancy is needed additional food for the mother's uterus, breasts and blood - all of them increase in size or quantity - as for the growth of the placenta. The increased need for food continues in the latter half of pregnancy, but during the last quarter, additional nutrients are especially needed for the rapidly growing fetus, which also needs to store some nutrients, especially vitamin A, iron and other micronutrients, and energy by storing fat. A proper diet during pregnancy helps the mother to gain additional weight that is physiologically desirable weight and to ensure the baby's birth.
Healthy women gain weight during pregnancy if they do not work too much. As a heavy person needs more energy to perform the same amount of physical work that a thin person, a pregnant woman also needs more energy. In industrialized countries, many women have an easy life during pregnancy, rest frequently and therefore reduce their energy needs. However, in much of Africa and some other regions, pregnant women are still active, even during the last months of pregnancy (Photo 4). The basal metabolic rate (BMR) almost always increases during pregnancy, which increases further the energy needs. Therefore, most women need more energy when they are pregnant, including those not working excessively. Women's overloaded in the developing world with little food and insufficient rest, weight loss is a real and dangerous possibility.
No doubt that abortions, losses and stillbirths are more common in poorly nourished women than in those with good nutrition. Dietary deficiencies may also increase the risk of fetal malformations. Acute malnutrition reduces fertility and thus the likelihood of conception. A woman with severe malnutrition stops menstruating. This is clearly a natural device to stop the loss of nutrients in the menstrual flow and to protect women from the rigors of pregnancy and childbirth. However, it is not clear lack of fertility in undernourished women as less serious. Moderately malnourished women are the majority in parts of Asia and Africa.
Nutrition of the mother influences the child's weight at birth: malnourished mothers can only expect low weight babies. Even a modest increase in energy consumption during pregnancy tends to increase the child's weight at birth.
In many developing countries from 50 to 75 percent of pregnant women have anemia. Anemia often contributes to high maternal mortality rates. All pregnant women must attend a clinic at regular intervals to undergo a prenatal test, which should include checking the levels of hemoglobin. They should receive practical advice on nutrition, taking into account the foods that are available in the locality and who may become mothers. It is generally accepted policy in many countries that pregnant women should be advised to take supplements of medicinal iron, or sometimes iron-folate.