Where a good and varied supply of food is available and affordable, everyone should be able to select and eat the foods that meet their nutritional needs.
Selecting a proper diet requires knowledge about changing nutrition needs throughout the life-cycle and how these needs can best be met from locally available foods. Encouraging family members to enjoy and choose a wide variety of foods can help them meet their needs. Choosing wisely is especially important when incomes are low and food supplies are insecure. Nutritional needs are influenced by age, sex, health status and activity levels, and the following groups often need special care.
Pregnant and Breastfeeding Mothers
Women need to eat enough before, during and after pregnancy to deal with the extra strain that pregnancy puts on the body. Babies - both before and after they are born also need to be well nourished. When a woman is pregnant or breastfeeding, she must meet the baby's nutritional needs as well as her own.
If the mother's diet does not satisfy the needs of her baby, the baby will draw on, and reduce, the mother's own stores of nutrients. This puts the mother at increased risk of illness and can affect the baby's development.
Pregnant and breastfeeding women should therefore be aware of the importance of obtaining additional foods to meet their and the growing baby's nutrient needs:
• Carbohydrates and fats: these supply the extra energy needed.
• Protein, vitamins and minerals (especially iron, iodine, calcium, folic acid and vitamins A, C and K): these are particularly important for building the baby's muscles, organs and tissues, bones and teeth and for the formation of haemoglobin and blood.
These needs can generally be met by eating a wide variety of foods including plenty of fresh fruits and orange coloured and dark green leafy vegetables. Fruit and vegetables are also a good source of fibre; this helps prevent constipation which is common during pregnancy.
Pregnant women should be encouraged to have regular medical checks to ensure that they are keeping themselves and the developing baby well nourished. If the mother is not getting enough of a particular nutrient relevant dietary advice should be given.
In some cases vitamin and mineral supplements might also be recommended, but these should be taken only as advised by a doctor. During pregnancy the requirement for iron is particularly high and supplements are often needed. Folic acid is another common supplement, as is iodine in certain areas.
Breastfeeding mothers need a varied, nutritious diet too. They should have adequate supplies of energy and protein. Lots of fluids, such as fruit juices and soups are also important.
Babies
Breastmilk is the natural food for babies. Breastmilk has the added advantage of boosting the baby's resistance to disease. It is safe, inexpensive and provides all the nutrients most babies need for the first six months of life. Breastfeeding can continue up to two years.
While breastmilk is the basic food of the baby, milk alone is not enough to meet the increased nutritional needs as the baby grows older. By six months babies should be introduced to other foods to supplement the energy, protein, vitamins and minerals provided by breastmilk. This will also accustom the baby to varieties in food flavours and textures.
Foods for babies require special preparation to make sure that they are soft, clean and easy to digest. To meet all of the baby's nutritional needs it will be necessary to add foods high in energy and other nutrients (oil, fruit, vegetables, legumes and animal products) to the family's staple food. Once the baby is accustomed to liquid and soft foods, and as the teeth appear, semi-solid and then solid foods can gradually be introduced to the diet.
Preparing safe and nutritious supplementary foods can take a lot of time and effort. Many mothers and fathers, especially young and first time parents, need practical advice and assistance to help them provide their babies with the foods they need.
Young Children
Young children are often the most at risk of being malnourished. They have very high energy and nutrient needs for their body size in comparison to adults. Proper care and feeding is essential for their normal growth, development and activity.
Children can eat many of the same foods as their parents. They should be encouraged to eat enough of a variety of energy and protein-rich foods and fruit and vegetables for growth and body maintenance.
Children cannot eat the same amount of food in one meal as adults. They also expend a lot of energy throughout the day. They should sustain energy requirements by eating small meals and snacks spread over the day.
Children need to maintain their diet of energy-rich and body-building foods throughout their growing years until they reach adulthood. They should be encouraged to exercise and stay active so that the high energy intake does not result in obesity.
Sick children must be encouraged to eat and drink, even if they have little appetite. They should be offered softer textured foods and the foods they like best. Lots of fluids milk, fruit juice, soups and clean water - are especially important when a child has diarrhoea.
Children recovering from fevers and sickness should also be given plenty of energy and nutrient-rich foods to eat.
Eating habits are established early on, so it's important to teach children at an early age how to get the best from food.
Adolescents
Adolescents grow rapidly and so have very high energy and nutrient needs. They need adequate intakes of vitamins and minerals, especially iron, calcium, vitamins A, C and D. In addition, adequate amounts of energy and protein are needed to sustain growth and development.
Special attention should be given to adolescent girls who need to be well nourished both for their immediate development and the future stresses of childbearing. Anaemia and calcium deficiency are common problems. Foods rich in calcium and iron should be encouraged.
Adolescent girls who become pregnant are at particular risk and must have additional nutrients for their baby's growth as well as for their own.
The Elderly
There is no set age at which a person is elderly. The ageing process is significantly influenced by culture, individual activity levels and general health status.
As people begin to feel the effects of old age, illness and loss of taste and thirst sensation can reduce appetite; loss of teeth can make chewing difficult; a variety of stomach and intestinal disorders can lead to digestive problems; disabilities and infirmities, coupled with poverty, loneliness and depression can make acquiring and preparing food difficult. All older people should therefore pay attention to their nutritional needs; many will need special help to do this.
Even though most people need less energy as they get older, the elderly need adequate protein, carbohydrates, fat, vitamins, minerals and dietary fibre. Women should have an adequate calcium intake throughout life to reduce bone loss.
Foods for the elderly should include a wide variety of grains, fruits, vegetables, legumes, meats and dairy products.
Consumption of high energy foods may be particularly important if appetite fails and overall food intake is limited. Maintaining adequate fluid intake is also important.
For those who find it harder to eat and digest foods, special preparation might be needed to make these foods more appealing and easier to digest.
For example:
• Boiling, steaming or baking food may be preferable to frying.
• Fatty meat should be avoided in favour of lean meat and poultry.
• More food should be eaten at the start of the day; food intake at the end of the day should be limited to a light supper.
People with High/Low Activity Levels
Food is the body's fuel. It therefore follows that the more active people are the more fuel they need, whereas less active people will need less fuel. For most people their work-related activities determine energy expenditure.
Those who eat more food energy than they use will put on weight. Those who eat less than they use up in energy will lose weight. When dietary energy intake balances with energy requirements, body weight remains fairly constant.
Measuring Dietary Energy
Dietary energy is measured in kilocalories (kcal for short).
• 1 g carbohydrate gives 4 kcal.
• 1 g fat gives 9 kcal.
• 1 g protein gives 4 kcal.
• 1 g alcohol gives 7 kcal.
Fat is a concentrated source of energy. It contains twice as many kilocalories per gram as carbohydrate (starch and sugar) or protein. Carbohydrate and fat are the main sources of energy for the body. When more is eaten than is needed any excess is converted into fat. This fat is stored and can be broken down and used for energy in the future.
The amount of energy needed to maintain a healthy body weight depends on a person's age, sex, physiological condition and physical activity level. Energy needs vary widely. The larger and more active a person is the more energy or calories is needed. Further information about the energy used up during different activities is contained in Section 4.
Weight Control
Having a proper body weight is important to good nutrition. Body weight can also affect the happiness and enjoyment of life. Being underweight can lead to malnutrition. Malnutrition often results in poor growth, lack of energy, reduced ability to work and other nutritional problems. Being very overweight (obese) is also a form of malnutrition and can lead to serious health problems including cardiovascular disease, diabetes and hypertension. Overweight people often find it harder to do physical work, exercise and stay fit.
What is the Right Weight?
An individual should not be too fat or too thin, but how much weight is too much and how little is not enough? There are several ways of evaluating the appropriate weight for an individual. Two of the most common methods use the body mass index (BMI) for adults and the weight-for-height index for children.
Body Mass Index
This index is a measure of fatness or leanness, and is calculated by dividing one's weight in kilogrammes by the square of their height in metres.
The formula is:
BMI = Weight in kg/(Height in metres)2
For example, an adult weighs 75 kg and is 1.7 metres tall. His BMI is:
If the BMI of an adult (except a pregnant woman) is:
• below 18.5, they are underweight;
• 18.5-25, they are within the normal range;
• 25-30, they are probably overweight;
• over 30, they are probably obese.
Therefore, the person in the above example would probably be over his desirable or appropriate weight.
Approximate Weights-for-Heights of Adults for Different Body Mass Indexes (BMIs) - Table 2.a
Weight (Kg) | |||
Height |
Body mass index | ||
(cm) |
18.5 |
25 |
30 |
146 |
39 |
53 |
64 |
148 |
41 |
55 |
65 |
150 |
42 |
56 |
68 |
152 |
43 |
58 |
69 |
154 |
44 |
59 |
71 |
156 |
45 |
61 |
73 |
158 |
46 |
62 |
75 |
160 |
47 |
64 |
77 |
162 |
49 |
66 |
79 |
164 |
50 |
67 |
81 |
166 |
51 |
69 |
83 |
168 |
52 |
71 |
85 |
170 |
53 |
72 |
87 |
172 |
55 |
74 |
89 |
174 |
56 |
76 |
91 |
176 |
57 |
77 |
93 |
178 |
59 |
79 |
95 |
180 |
60 |
81 |
97 |
182 |
61 |
83 |
99 |
184 |
63 |
85 |
102 |
186 |
64 |
86 |
104 |
188 |
65 |
88 |
106 |
190 |
67 |
90 |
108 |
192 |
68 |
92 |
111 |
Adapted from Felicity Savage King and Ann Burgess, Nutrition for Developing Countries, 1993.
Table 2.a can be used to work out an adult's BMI, based on the above formula. The first column is height in centimetres (cm). The second, third and fourth columns indicate the weights equal to a BMI of 18.5, 25 and 30 respectively, for each height.
To evaluate a person's weight, find their height in the first column and compare their weight to the weights in the next three columns along that line. If the weight is less than that in the «18.5» column, then the person is underweight. If the weight falls between the weights in the «18.5» and «25» columns the BMI is within the normal range. If the weight is over the number in the «25» column, the person is probably overweight; if over the number in the «30» column, the person is obese.
Care needs to be taken when utilising BMI to determine what is an appropriate weight for an individual. Desirable body weight is related to age and sex as well as height. For example, men are generally heavier than women of the same height because men tend to have a larger bone structure and greater muscle mass.
Whilst body weight will fluctuate to a certain extent, it is advisable to avoid extremes of weight loss or weight gain. The real risk to health comes from being over-fat, not just from being overweight. It is much harder to lose and keep excess weight off, than never to gain it.
Weight-for-Height Charts
While BMI is a valuable tool for monitoring nutritional status of adults, it is not as useful for children whose bodies are constantly changing and growing. Weight-for-height tables and charts are commonly used to see if a child may be either too thin or too fat in relation to their height.
Figures 2.1 and 2.2 provide weight-for-height curves that correspond to the 97th, 80th, 50th, 20th and 3rd percentiles of an internationally recognised reference group of children. The weights-for-height of well-nourished children generally fall between the 3rd and 97th percentile lines. The use of percentiles allows us to compare a given child's weight-for-height to those of other children.
Figure 2.1 - Weight by Stature (55-145 cm in Height)
Figure 2.2 - Weight by Stature (55-135 cm in Height)
For example, if a child's weight-for-height corresponds to the 80th percentile, then that child is heavier than 80% of the other children of the same height.
To use the charts, determine a child's weight-for-height by finding, on the appropriate chart for boys (Figure 2.1) or girls (Figure 2.2), their height (cm) along the horizontal axis and their weight along the vertical axis and marking the point where they meet. Then determine where that point falls in relation to the percentile curves drawn on the charts.
When a child's weight-for-height is below the 3rd percentile, the child is probably undernourished and needs special attention. In such cases the child should be referred to a doctor or local health unit and evaluated to find out the cause. A child whose measurements are above the 97th percentile is very likely to be overweight, and the child's physical activity and food intake should be monitored.
Healthy, well-fed babies and children grow normally and they should be weighed and measured regularly. In many countries growth charts based on weight-forage measures are commonly used for monitoring children's growth.
A child's body undergoes rapid changes during growth, and caution must always be used when trying to assess a child's nutritional status, especially on the basis of a single measurement. Just as good nutritional status is not assured when a child's measurement falls within a normal range, neither is poor nutrition always confirmed when it falls outside this range.
Gaining Weight
Being significantly underweight can be a serious problem for anyone, especially children, adolescents, pregnant and breastfeeding mothers and the elderly. Underweight in children is usually caused by a combination of inadequate food intake and recurrent episodes of infections.
Health problems can also lead to underweight among older people, and these should be investigated if people fail to gain weight by eating more.
To gain weight people should try to:
• eat more of their regular foods
• eat more frequent meals and snacks
• eat a greater variety of food
• make sure they are eating enough protein and energy
• increase the energy content of their food by adding fats, oils and sugar.
Although activity uses up energy, it's still important to keep fairly active even when trying to gain weight. Exercise helps stimulate appetite and is important for all round good health.
Relaxation is also important. Worry and stress can cause weight loss, so stressful situations should be avoided or minimised if possible.
Losing Weight
In many countries, particularly in urban areas, more people are becoming overweight and obese (more than 20% above the normal weight-for-height, or BMI >30).
Losing weight means eating less food or less high energy containing foods and exercising more. But it doesn't mean starving oneself; everyone has a basic nutritional requirement to meet each day. Rather than going without meals altogether, the way to lose weight is by changing the diet and exercising on a regular basis.
Maintaining one's proper weight, when attained, is nutritionally preferable to periodic cycles of weight gain and crash-dieting to lose weight again.
Those who need to lose weight should:
• eat less energy-dense foods, especially ones high in fat
• eat more foods rich in fibre, ea. fruit, vegetables and whole grain products
• substitute foods rich in starches, ea. rice, pasta, bread and potatoes for some of the more energy-rich foods
• eat regular meals; constantly going hungry is not the answer
• drink water whilst eating; that will help them feel full too
• drink less alcohol
Most importantly, exercise should be increased to use up energy stores. The best advice is to start off by being more active in everyday life, for example, by simply walking more. Then, providing one is in general good health, more vigourous exercise sessions can be gradually introduced as part of a daily routine.
Applying this Information at the local level For a greater understanding of how this information applies at the local level the following might be examined: • Which population groups in your community require special dietary attention? • What are the most Important local dietary and nutrition problems? Are many people either underweight or overweight? • Are there local hod customs or feeding practices that are particularly Important in promoting or hindering adequate dietary Intakes? • How do most people in your community learn about their nutrition needs and how to choose good diets? • How does your community promote and monitor children's growth and development? |
