Nutrient requirements by age group

HEALTH

A balanced diet is one that provides all nutrients in required amounts for maintaining health and general wellbeing.

However, it's difficult for some to identify the right foods for a specific nutrient, quantity required/ needed by different age groups.
Today we look at the main nutrients (briefly) and their use in the body then the most important at different age groups.

Major nutrients (proteins, carbohydrates, fats) are required in the body in large quantities while minor nutrients (vitamins, minerals) are required in the body in small quantities.
A.    Proteins
Required for growth, repair and maintenance of tissues and cells.
These have a secondary function of providing energy to the body.
sources; meat, fish, poultry and their products like eggs, milk and its products like yoghurt, cheese, nuts, beans, soya, sesame and amaranth seeds.
B.    Carbohydrates
These provide energy to the body in form of calories.
Sources; maize, millet, cassava, oats, rice, potatoes, sweet potatoes, yams, wheat and its products.
C.    Fats
Provide energy, facilitate digestion of vitamins (fat soluble), cushion to body organs and skin.
Sources; butter, ghee, margarine, plant oils like peanut, avocado, sunflower, coconut, olive, and palm oils or fat spreads made from these, they are also a good source of vitamin A, D and E and can provide a good balance of omega 3 and 6 essential fatty acids.
Fats high in saturated fats such as butter, lard, dripping and some hard vegetable fats should be limited / used only occasionally.
These are used in food preparation hence consumed within foods served.
D.    Vitamins
Required in the body in small quantities and support / facilitate body processes like vitamin k in blood clotting, vitamin A for vision, vitamin B1, B2, B3 in release of energy/glucose, proteins, fats to the blood after digestion, vitamin C, E -antioxidants protecting the body against cancer, facilitate mineral absorption like vitamin D in calcium absorption.
Sources; fruits and vegetables whole meals/grains meat, poultry and their products.
E.    Minerals
These facilitate body processes like calcium, phosphorus in formation of strong healthy, bones and teeth, magnesium in energy release, muscle construction and relaxation, hormonal functioning and release like zinc, anti-cancerous/anti-oxidants like selenium, potassium and sodium in transmission of nerve impulses and maintenance of body pressure.
Sources; mainly found in fruits and vegetables, whole meals/grains meat, poultry and their products.
F.    Water.
This is crucial for every system in your body and It's also the main making up the body (Approximately 62 percent of your body weight is water).
You can go for weeks without food, but you can't last more than a few days without water.
•    Water improves brain function and mood, acts as a shock absorber and a lubricant in the body.
•    Helps flush out toxins, carry nutrients to cells, hydrates the body, and prevents constipation.
A mild dehydration can make one tired, impairs concentration and physical performance.

You don't have to chug water to stay hydrated, Fruits and vegetables can also be a great source like spinach or watermelon, cucumber to stay hydrated.

 
1.       Babies (0-2years)
Breast milk (exclusive) is best for a new born baby for the first 6 months.
However, due to  work schedules, quantity of breast milk, this usually done for 3-4 months then formulae (a mix of different natural foods processed and reconstituted to much that of breast milk) can be introduced.
At birth colostrum a pre-milk secreted after a mother gives birth is rich in antibodies that increase a baby's immunity to disease.
It contains anti-infection agents, anti-inflammatory factors, growth factors, enzymes and hormones, essential for growth and development.
This is followed by a thicker mature milk supplying the baby's nutritional needs completely for 6 months which further boosts their resistance to infection.
This milk is composed of fine digestible globules, all proteins, vitamins, minerals that babies require at this age.
In cases of work schedules, low milk, illnesses or death that a baby can't exclusively breastfeed, substitute breast milk with;
•    Goats milk- has nutritional quality like human milk though expensive and rare.
•    Cow's milk- good but needed to be diluted before use since its content especially calories double for that of human milk and cause obesity etc.
•    Soya milk- after 1 year accept if a child is lactose intolerant (cannot digest lactose) or having galactosemia (cannot breakdown galactose sugar in milk).
•    Infant formulae- sold with labels specifying age groups however, consider authenticity of manufacture.
•   
As different foods are introduced, proteins take up the highest daily percentage compared to other nutrients.

A)    4-6 months
Offer a mixed diet by the age of 6 months- the onset of weaning accompanied by breast milk, formulae.
Introduced solid foods that are easy to digest and unlikely to provoke allergic reaction.

•    Milk (breast or cows)/diary- 600ml, milk products like yoghurt can be part of it to provide mainly the protein, some fat and carbohydrate.
Yoghurt not advisable because some contain artificial colours, flavours and additives like complex starches which cannot be handled in the baby's system unless lacking these.
•    Low fibre cereals like rice mixed with milk.
•    Fruit and vegetable - softly cook, sieve/ purée so as to eliminate indigestible husks e.g. peas.
Sweets, cakes can be given occasionally but avoid high salt foods and puddings containing artificial colours or flavours.



B)    6-12 months
•    Milk (can be mixed with porridge), eggs (well cooked), soft cooked minced or pureed chicken, meat or fish.
•    A more solid/ lumpier texture can be introduced like whole meal bread and cereals like oats (cereal/porridge).
•    Fruits and vegetables- lightly cooked or raw and soft like bananas, water melon, tomato.
Unsweetened and diluted orange juice with meals to facilitate iron absorption especially for meat-free meals
•    Occasionally provide savoury foods rather than sweet ones. Fruit juices are not necessary but can be diluted to four parts of water or just water offered and restricted at meal time.
Moderate amounts of butter can be used preferably unsalted and small amounts of jam on bread occasionally.
Cow's milk to children under 12 months doesn't provide enough iron hence incorporate soy, eggs (yolk)to increase iron content.

Infants (2-5 years)
Calorie needs increase with age as well as amount of food type they need to fuel growing bones and muscles.
These changes in nutrient requirement differ between sexes and the child may need less or more than the average.
1.    Carbohydrates
Provide these at each meal with at least one snack during the day as they are a good source of calories, provide B vitamins essential for growth, rich in dietary fibre preventing constipation, intestinal diseases and prolong satiety.  
2.    Proteins
From milk, beef, fish, poultry, soya, eggs, cheese, yoghurt, beans, nuts.
3.    vitamin and minerals
Main vitamins at this stage are A, C and D along minerals zinc, calcium, Iron.  However, good quantities of these are incorporated within protein and carbohydrate foods.
Milk (skimmed) in moderation for calcium with alternatives like calcium-fortified soy milk, tofu or tofu pudding, dark-green leafy vegetables and other calcium-rich foods.
Less milk is required if there's consumption of a larger amount of other calcium-rich foods.
-    Vitamin A is important for your toddler's visual development and to see in dim light, supports the immune system, maintains healthy skin.
Sources; Cheese, Eggs, Fortified low-fat spreads, dark green /orange vegetables and fruit like carrots, sweet potatoes, mango, spinach and kale.
-    Vitamin D from fortified breakfast cereals, eggs, fortified margarine.
-    The skin-healing properties of vitamin C help to repair bumps and scrapes on your toddler helps the body absorb iron and encourages the development of white blood cells, which help to fight infection.
(Oranges, Tomatoes, mangoes, strawberries, passion fruits, Peppers, Broccoli).
-    Zinc aids healing and plays a role in the creation of new cells, from Meat, Milk, Cheese, Bread, Cereals, pumpkin (porridge, seeds), grains, nuts.
          -      Iron (meats, fish, egg yolk, liver, avocado, soya, millet) due to rapid growth and development.  
-    Calcium for building strong and healthy teeth, bones, efficient nervous system and for muscle action. 
Vegetarian /vegan sources include tofu, nuts and nut butters, seeds, figs, beans, lentils and pulses, okra, oranges, spinach, flax seeds, lentils, cracked wheat and barley, fruits and vegetables.
4.    Fat- providing lots of calories in a small amount consumed, without making the diet of the child bulky.
Foods of high fat, salt or sugar content, like fried chicken, chips, soft drinks or sugar added drinks should be chosen least/given with limitation.

5.    Water -the best drink to keep one hydrated, don't substitute to water tea, coffee or other caffeinated drinks.


Children 5-12 years
Nutrient needs increase with the sources as given in age groups mentioned, more quantities are required and these also differ depending on the sex.
Servings increase approximately by two after 5 years. Males likely require more than the females but one may take in more or less than the average values given.
Carbohydrates, Proteins, Calcium and Iron mainly needed at this stage.
Provide/encourage health snacks as these tend to start eating away of home and have the luxury of making their own choices for the first time.

Adolescents (12-24 years) boys and girls
The same diet with increase in quantity required due to growth and increase in appetite.
    Increase fibre in the diet and decrease the use of salt.
    Drink water, avoiding drinks that are high in sugar.
Requirements for iron, calcium, zinc, and Vitamin D are particularly increased in adolescence, due to rapid physical growth during adolescence.
Regular exercise in the teen years builds a strong skeleton for life.
-    Calcium needs during adolescence increase due to rapid increase in lean body mass and skeletal growth.
-    Zinc is especially important in adolescence because of its role in growth and sexual maturation while a deficient diet results in growth failure and delayed sexual maturation.
Inadequate nutrition during adolescence can potentially retard growth so that the adolescent remains short and thin, full height potential may not be reached hence one remains stunted.
Sexual maturation may be delayed with late onset of puberty, impairs work capacity and one may feel tired all the time.
Adolescent /teenage girls and young women (above 20 years) become conscious about their body changes and hence tend to avoid food causing conditions like anorexia and iron deficiency anaemia set in.

Anorexia nervosa, often referred to simply as anorexia, is an eating disorder, characterized by low weight, food restriction, fear of gaining weight, and a strong desire to be thin.
These see themselves as overweight even though they are, in fact, underweight.
They often deny that they have a problem with low weight, weigh themselves frequently, eat small amounts, and only eat certain foods.
Some exercise excessively, force themselves to vomit, or use laxatives to produce weight loss.  Complications may include osteoporosis, infertility, heart damage, stopping of menstrual periods.

Causes
Environment mainly triggers eating disorders this eating disorder can also be due to is based on genetic predisposition, personality traits, and environmental factors.
Examples of environmental factors include:
-    Effects of the thinness culture in media, that constantly reinforce thin people as ideal stereotypes.
-    Professions and careers that promote being thin and weight loss, such as ballet and modelling.
-    Family and childhood traumas like childhood sexual abuse, severe trauma.
-    Peer pressure among friends and co-workers to be thin or be sexy.
-    Anxiety, low self-esteem, an obsessive personality as a perfectionist (even in body shape/size).
Physical signs and symptoms of anorexia may include:
•    Extreme weight loss or not making expected developmental weight gains
(A low body mass index for one's age and height)
•    Abnormal blood counts
•    Fatigue
•    Insomnia
•    Dizziness/ fainting
•    Bluish discoloration of the fingers
•    Soft, downy hair covering the body
•    Amenorrhea, a symptom that occurs after prolonged weight loss; causes menstruation to stop, hair becomes brittle, and skin becomes dry, yellow and unhealthy.
•    Constipation and abdominal pain
•    Intolerance of cold
•    Irregular heart rhythms
•    Low blood pressure
•    Dehydration
•    Swelling of arms or legs
Behavioural symptoms of anorexia include attempts to lose weight by:
•    Severely restricting food intake through dieting or fasting
•    Exercising excessively
•    Bingeing and self-induced vomiting to get rid of food, which may include the use of laxatives, enemas, diet aids or herbal products
Emotional signs and symptoms may include:
•    Preoccupation with food, which sometimes includes cooking elaborate meals for others but not eating them
•    Frequently skipping meals or refusing to eat.

Anaemia sets in as a result of on not taking in the right foods with components to help in formation and release of blood with intentions of losing / maintaining weight and these include;

    Iron
This is involved in manufacture of haemoglobin the red pigment in red blood cells which helps in transportation of oxygen from the blood stream to other body parts.
It's also required for manufacture of myoglobin, pigment that stores oxygen in muscles.
Sources; - organ meats especially liver and kidney, poultry and other meats, fish, egg yolk, whole grains, beans, nuts, lentils, dark green leafy vegetables.
Plant based foods should be taken with vitamin C food/ drink like peppers, orange juice so as to break down the plant iron to simpler form absorbable by the human body.

    Copper
Facilitates iron absorption and makes stored iron available for red blood cell formation, lack causes iron-deficiency anaemia.
Sources; - liver, shellfish like oysters, mushrooms, nuts, cocoa,

    Folate/folic acid
This is involved in formation of iron- containing protein in haemoglobin needed to make red blood cells.
Folate plays an integral role in DNA, RNA and protein synthesis. Thus, adolescents have increased requirements for folate during puberty.

Sources; - liver, yeast, green leafy vegetables, broccoli, wheat germ, pulses, fortified breakfast cereals, orange juice, bread, milk, and dried beans or lentils.

    Vitamin B12 (cobalamin)
Involve in red blood cell formation and transportation of folate into cells
                                Sources; -meat, fish, poultry, eggs and dairy products.

6.    Adults 24-60 years (men and women)
The nutritional needs in adults differ slightly according to gender with calcium essential for both.
Eating a well-balanced diet with lots of calcium (low-fat dairy products, canned fish with soft bones which you eat, and fortified orange juice).
Vitamin D (fortified milk and sunlight exposure) to facilitate calcium absorption
Phosphorous (animal products, dairy, and beans) can help provide the minerals that will be stored in the bones for the rest of her life.

Males - vitamins C, K, B1, B2 and B3, and zinc as below respectively;
-For carrying out anti-oxidative activities in the body and iron absorption.
-Formation of some body proteins and also normal blood clotting.
-Release of energy from carbohydrates, fats and also prevent built up of toxic substances in the body.
-Release energy from foods and for the functioning of B3 and B6 (releases energy from proteins).
-Zinc aids in functioning of many body enzymes.

Females - iron, and folic acid compared with males of similar age.
Iron can help build more haemoglobin to replace blood lost through menstruation.
This is a stage of ‘child bearing cycle' hence folic acid recommended (essential for a baby's development).



For menopausal women
Sets in between 45 to 50 years, thinning of the bones is common in postmenopausal women because of hormone-related changes.
Recommendations include:
  Calcium rich foods or calcium supplements as prescribed by a doctor.
  Weight-bearing exercises - like walking or weight training strengthen bones and help maintain a healthy body weight.
  A high-fibre, low-fat and low-salt diet - a diet high in phytoestrogens reduces many symptoms of menopause, such as hot flushes.

7.    Elderly 60+
These require less energy than a younger individual due to reductions in muscle mass and physical activity however, whatever your age, it's important to eat a healthy, balanced diet.
Emphasise healthy foods, seconded with supplements. However, supplementary doses of micronutrients can both prevent deficiency and support immune functions, very high dose supplementation (example, high dose zinc) may have the opposite effect and result in immune-suppression.
Daily requirements for elderly people differ due to;
- Difficulty in getting adequate nutrition because of age or disease related impairments in chewing, swallowing, digesting and absorbing nutrients.
- Decreased production of chemicals (digestive enzymes) to digest food, changes in the cells of the bowel surface and drug-nutrient interactions.
-Selenium deficiency, a mineral important for immune function. Impaired immune function affects susceptibility to infections and tumours. Include; mushrooms, legumes (beans and peas), oats, eggs, poultry, shell fish.
Vitamin B6 helps to boost selenium levels, higher intake for people aged 51-70 is recommended.
-Protein is similar to young adults for maintenance and repair of body cells and tissues.
Utilise law fat animal sources, fish and other plant based sources.
- vitamin D is important for bone health and prevents osteoporosis, increase intake to reduce risk for age related bone loss and fracture.
The best source of vitamin D is safe exposure to UV sunlight for a short period of time in the sun each day.
-Calcium for maintaining bone structure and mass.
Calcium requirement increases with age yet its absorption in the body reduces therefore one may need extra serves of low fat milk, yogurt and cheese.
Eating calcium-rich foods help prevent osteoporosis.
Avoid Using raw bran like wheat bran in cereal as this can reduce the absorption of calcium in foods such as dairy or when you take a calcium containing medication if taken at the same time. This may be an issue in managing healthy bones.
Choose lower fat varieties when you can, or eat higher fat varieties in smaller amounts.
-Iron intakes reduce after age 50 due to better iron conservation and decreased losses in postmenopausal women compared with younger women.
-Vitamin A reduces because too much increases risk of bone fracture.
Liver is high in vitamin A and a good source of iron, avoid liver or liver products, such as pate, more than once a week, or eat smaller portions avoiding supplements containing vitamin A or fish liver oils (which also contain high levels of vitamin A).
-Less salt
Too much salt can raise blood pressure, increasing risk of health problems such as heart disease.
Check food labels before you buy and choose ones containing less salt since most of it is consumed from processed foods.
-Drink more water
Along with fluids daily to keep hydrated at least 6 times a day and more in warmer weather or if exercising.
Drinks with a lot of caffeine, like strong tea and coffee, make the body produce more urine causing dehydration therefore if mostly drinking such drink also some water to keep hydrated.
-Eating fibre rich foods for digestion since constipation tends to become a ‘nuisance' as you get older and these prevent constipation and other digestive problems.
-Plenty of fruit and vegetables at least five portions of vegetables and two portions of fruit a day.

Lydia Kusasira is a Food Technologist