Nutrition through the lifecycle

An individual's needs for nutrients and energy change over the life span. For example, while a typical adult woman may need only 6.7 milligrams of calcium per pound of body weight, a nine-month-old infant needs 27 milligrams of caclcium per pound of body weight.

It is during a body's growth periods that the need for nutrients is greatest. These occur during infancy, adolescence, and pregnancy. Once the growth period stops, energy needs and the need for certain nutrients declines.

The reasons behind a person's food choices also varies across the life span because social, psychological, economic, and leisure roles change during that time period. For example, during the teenage years, the opinions of peers and body image concerns become especially important. On the other hand, adults are more likely to be influenced by their health needs.

 

Infants
The member's manual discusses breastfeeding and bottlefeeding options. Research shows that breastfeeding is good for both baby and mother. If teenagers learn about the benefits of breastfeeding, they may be more likely to consider it when they are parents.

Generations ago, breastfeeding was the preferred feeding method. As formula became readily available, bottlefeeding became more popular. At the same time, a trend toward feeding babies solid food at an early age became popular as well. Today, trends in infant feeding are changing again. Breastfeeding has gained in popularity because of the nutritional benefits and antibodies (to protect againt infection adn allergies) that breast milk provides for the baby.

Food for the first year
Age Food
Birth to 12 months
Breastmilk or formula is the most important food
  • Begin and continue breastmilk or formula.
4 to 6 months
Babies can hold up their heads and move them around. The suck-swallow reflexes are not as strong, and food is no longer automatically pushed out of their mouths with their tongues during feeding.
  • Start cereals.
  • Start vegetables, fruits, and juices. Use real fruit juices, not a sweetened fruit drink. Use commercial baby food or unseasoned strained and mashed table foods.
5 to 6 months
Babies can sit up in a high chair with support.
  • Start plain meats which have more iron and protein than combination dinners or soups.
6 to 9 months
Babies begin to use their thumb and forefinger in a pincer-like movement. They pick up pieces of food and grab what they want.
  • Start finger foods. Teething crackers and other foods such as toast, or dry, unsweetened cereal are good choices.
  • Practice using a cup to drink milk, juice, or water as an adult holds it. Two handle cups and a spout are easiest to use.
9 to 12 months
Babies are able to chew soft foods. Muscle control and hand-eye coordination is good. They may still need help drinking from a cup.
  • Start table foods that are well chopped or mashed. Avoid giving hard foods, such as nuts, popcorn, or raw vegetables; babies easily choke on these items.
All ages
Sugary desserts, candy, and liquids containing few nutrients, such as soda pop are not good for weight or teeth.
  • Avoid or limit sweets and sugary liquids.

For a printer-friently version of this chart, click on the icon to download.
Note: Must have Acrobat Reader.

Early Childhood
Young children like to feed themselves just like they like to do everything else for themselves. It's easy to spill milk and make other messes as they learn how to eat! Parents and babysitters can help young children learn to eat and feed themselves by providing:

Children who have positive experiences during family meals are more likely to develop healthy attitudes. This is an opportunity to reinforce good eating habits and to introduce a wide variety of foods. However, food should not be used to calm or cheer up children. That may result in children associating food with emotions and not hunger.

Children have small stomachs and cannot eat a lot of food at one time. It is easier to eat several snacks and meals than to eat three large meals a day. Bite-size pieces of raw fruits and vegetables and cheese cubes are ideal snacks. Other delicious, nutritious snacks include the following.

Nutrients in snack foods
Snack Major nutrient (s)supplied
Low-fat peanut butter and low-salt wheat crackers
  • Protein
  • Complex carbohydrates
Whole-grain muffins and bagesl
  • Fiber
  • Complex carbohydrates
  • B-vitamins
Raw vegetables with a nonfat yogurt dip
  • Vitamin A
  • Calcium
  • Fiber
Unsalted pretzels
  • B-vitamins
  • Iron
Air-popped popcorn
  • Fiber
  • B-vitamins
Rice cakes with fruit preserves
  • Complex carbohydrates
Frozen nonfat fruit yogurt
  • Calcium
  • Protein
Fresh fruit mixed into nonfat yogurt
  • Vitamins A and C
  • Calcium
  • Fiber
String cheese
  • Calcium
  • Protein
Dried fruit bits (raisins, etc.)
  • Vitamin A and C
  • Iron

For a printer-friendly version of this chart, click on the icon to download.
Note: Must have Acrobat Reader.

Overall health does not depend on a single food or a single meal, but on making good nutritional choices over a period of time. Usually there are nutritional equivalents that can be substituted for the foods a child refuses to eat. The following tips can help make foods fun.

Another factor that contributes to food selection is television. Children are influenced by the foods advertised on television. Before the age of seven or eight, few children can think critically about those advertised foods and may beg parents to buy a frequently advertised food.

Some children do not like milk or certain dairy products. Although some parents may be very concerned, there are nutritional alternatives to “sneak” milk in a child’s diet.

Consider certain dishes and combination foods that include milk and/or other dairy products, such as:

What about ice cream? Ice cream, ice milk, and frozen yogurt are made from milk so they have calcium and other nutrients found in milk. However, they are also higher in fat and sugar. On occasion, ice cream can count as a serving from the Milk, Yogurt, and Cheese food group, but when this happens, the use of other fats and sweets should be reduced.

If a child has trouble digesting milk, some alternatives include:

Teenage Years
A child’s body begins a period of rapid change in size and shape approximately around the age of 10 years in girls and 12 years in boys. This is called the “adolescent growth spurt.” During the next four years, an average girl may grow 10 inches taller and gain 40 to 50 pounds. An average boy may grow 12 inches taller and gain 50 to 60 pounds. At the same time, their body shape begins to change, too.

The adolescent growth spurt requires many different nutrients. Calcium is especially important for bone growth and health because 45% of the bone an adult has is built up during adolescence. See the chart below for sources of calcium and what to do if a teen has trouble digesting milk or doesn’t like milk.

Alternative Sources of Nutrients in Milk
Nutrients in Milk
Alternative sources
Calcium Yogurt, cheese (low amounts in cottage cheese), dark green leafy vegetables (especially broccoli), kale, eggs, dried beans, tofu (soybean curd), salmon, and tortillas made with cornmeal fortified with calcium.
Vitamin A Deep yellow fruits and vegetables (such as carrots, squash, peaches, and cantaloupe), dark green leafy vegetables, watermelon, cheese, eggs, and liver.
Vitamin D Eggs, tuna, liver, salmon, (and sunshine on skin).
Protein Chicken, beef, fish, dried beans or lentils, nuts and seeds (peanut butter), eggs, cheese, yogurt, and breads and creals.
Riboflavin Whole-grain cereals and breads, meat (especially liver), dark green leafy vegetables, and eggs.

For a printer-friendly version of this chart, click on the icon to download.
Note: Must have Acrobat Reader.

Although some teenagers become concerned that they are not changing as rapidly as their friends or other classmates in school, there is wide variation in the age at which the adolescent growth spurts starts. It is generally more dependent on the hereditary characteristics than on being a certain age.

How an adolescent feels about their body is closely related to how they feel about themselves. It is important for teenagers to:

It is important to emphasize that changes in body size and shape are part of normal adolescent development. Females gain proportionally more body fat during this time, while males gain proportionally more muscle and bone mass.

One of the changes taking place during adolescence is the varying hormonal levels in the body. These hormones are responsible for the changes seen in the physical development of the body and secondary characteristics such as facial hair growth and deepening voices.

Pregnancy
Pregnancy is a special time in a woman’s life. Healthy eating can increase the chances of having a healthy baby. Gradual weight gain is important; 2-4 pounds during the first three months, then a little less than 1 pound per week for the remainder of the pregnancy. A total gain of 25-35 pounds is recommended.

If a woman is overweight at the beginning of the pregnancy, she should not diet, but instead limit the amount of desserts and other “extras.” She needs to continue a gradual line of weight gain parallel to the lines on the Weight Gain during Pregnancy chart in Member’s Manual Level D (p. 9).

If a woman is underweight at the beginning of pregnancy, she should increase her food intake and continue a gradual line of weight gain parallel to the lines in the above mentioned chart.

In addition, a pregnant woman has specific water and fluid needs, including to:

All the weight gained goes directly to the baby and the mother’s tissue stores. Since the majority of the weight gain goes to the baby, a small weight gain can mean too small a baby. The following chart describes the location of the weight gain.

Weight gain in pregnancy
Time Where
First trimester blood volume and uterus
Second trimester tissue storage
Third trimester growing fetus and its brain development

For a printer-friendly version of this chart, click on the icon to download.
Note: Must have Acrobat Reader.

A pregnant woman’s lifestyle and poor nutrition habits can lead to a low birth weight baby (less than 5 1/2 pounds). Low birth weight babies are more likely to have medical complications including:

Low birthweight babies are related to 70% of infant deaths. In particular, the following habits are associated with low birthweight babies:

Substance abuse during pregnancy
Risks associated with substance use in pregnancy
Substance Unborn baby Infant/child
Alcohol
  • Stillbirth
  • Prematurity
  • Low-birth weight
  • Fetal Alcohol Syndrome (FAS)
  • Failure to thrive
  • Mental retardation
  • Lenaing disabilities (FAS related)
Caffeine
  • Low-birth weight
 
Cocaine
  • Stillbirth
  • Prematurity
  • Physical abnormalities
  • Addiction
  • Low-birth weight
  • Neurobehavioral changes
  • Sudden Infant Dealth Syndrome (SIDS)
  • Withdrawal symptoms (seizures, irritability, feeding difficulties, tremors, etc.)
Heroin
  • Stillbirth
  • Prematurity
  • Brain hemorrhages
  • Addiction
  • Low-birth weight
  • Withdrawal symptoms (seizures, irritability, feeding difficulties, vomiting, diarrhea, sweating, etc.)
Marijuana
  • Prematurity
  • Low-birth weight
  • Facial abnormalities
  • Labor and delivery effects
  • Neurobehavioral changes
Tobacco
  • Stillbirth
  • Low-birth weight
  • Sudden Infant Death Syndrome (SIDS)
  • Growth deficits
  • Learning problems in school
  • Respiratory illness

For a printer-friendly version of this chart, click on the icon to download.
Note: Must have Acrobat Reader.


Older Adults
Throughout a lifetime, three of the keys to good health have been to:

Although these keys cannot guarantee good health, they can help an individual stay healthy as they grow older or perhaps improve health. However, older adults often have special nutritional needs because:

After the teen years, the need for calories decreases approximately 5% every 10 years. Thus, a 60-year-old needs 20% fewer calories than a 20-year-old of the same weight. The best way for older adults to stay at the same weight is to:

The vitamin and mineral needs of healthy older adults appear to be similar to those of younger adults, although few studies on the nutrient requirements of the elderly have been conducted. Recent studies have shown that although older adults need fewer calories, the requirements for protein and calcium were somewhat higher in older adults than in younger adults. One explanation for these results could be that older adults absorb these nutrients less efficiently. Thus, older adults should be encouraged to consume recommended amounts of protein foods including milk, especially since a common problem among older adults is their rejection of meat and milk. However, as with other age groups, excess protein should be avoided.

Many older adults have difficulty chewing and swallowing food. Resolving these problems is critical to the nutritional status of the elderly. The following suggestions for easy to chew and swallow protein-rich foods may be helpful:

Another problem characteristic of the elderly is diminished thirst. Although the kidney usually concentrates the urine to conserve body water, the elderly tend to excrete a more dilute urine. In addition, an aging kidney loses functioning units and is less able to cope with stress. This situation may result in a decreased amount of body fluids; the composition of these body fluids may change as well which can be potentially fatal.

It is extremely important to make certain that older persons drink sufficient fluids to replace fluid losses. Dehydration is a serious threat to the elderly. Fruit juices, milk, and even coffee, tea, soft drinks, “ades,” popsicles, ices, and gelatin desserts are mainly water. Fluids should not be allowed to replace food at mealtimes but should be offered at meals and encouraged between meals.

 

Back to top

 

© Copyright (2002) Purdue University, West Lafayette, Indiana, 47907. All Rights Reserved.