For instance, 10 percent of 6-year-olds weigh 55 pounds or more, and 10 percent weigh 36 pounds or less.
Average differences in height and weight between boys and girls increase during the preschool years. Although at age 2 the differences are relatively small, during the preschool years boys start becoming taller and heavier, on average, than girls.
Profound differences in height and weight between children in economically developed countries and those in developing countries.
Muscle size increases, and children grow stronger.
Bones become sturdier.
The sense organs continue to develop. For instance, the eustachian tube in the ear, which carries sounds from the external part of the ear to the internal part, moves from a position that is almost parallel to the ground at birth to a more angular position. This change sometimes leads to an increase in the frequency of earaches during the preschool years.
Providing a variety of foods, low in fat and high in nutritional and iron content –
Foods that have a relatively high iron content are particularly important: Iron deficiency anemia, which causes constant fatigue, is one of the prevalent nutritional problems in developed countries such as the United States.
High-iron foods include dark green vegetables (such as broccoli), whole grains, and some kinds of meat such as lean hamburger.
Allowing development of natural preferences
Exposing children to a wide variety of foods –
As long as their overall diet is adequate, no single food is indispensable. Exposing children to a wide variety of foods by encouraging them to take just one bite of new foods is a relatively low stress way of expanding children’s diets.
Healthy children have about7 to 10 colds and other minor respiratory illnesses in each of years from age three to five
Runny nose due to common cold is most frequent
Majority of US preschoolers are reasonably healthy
Minor illness permits children to understand their bodies better, to learn coping skills that will help them deal more effectively with future, more severe diseases. And to help them understand better what others who are sick are going through. This ability to put oneself in another’s shoes, known as empathy, may teach children to be more sympathetic and better caretakers.
Before the age of 10, children have twice the likelihood of dying from an injury than from an illness.
Children in the United States have a 1 in 3 chance every year of receiving an injury that requires medical attention.
Danger of injuries
High levels of physical activity - It is this physical activity, in combination with the curiosity and lack of judgment that also characterize this age group, which makes preschoolers so accident-prone.
Even tiny amounts of lead can permanently harm children.
Exposure to lead has been linked to lower intelligence, problems in verbal and auditory processing, and hyperactivity and distractibility.
High lead levels have also been linked to higher levels of antisocial behavior, including aggression and delinquency in school-age children. At yet higher levels of exposure, lead poisoning results in illness and death.
Poor children are particularly susceptible to lead poisoning, and the results of poisoning tend to be worse for them than for children from more affluent families.
Children living in poverty are more apt to reside in housing that contains lead paint, or to live near heavily trafficked urban areas with high levels of air pollution.
Many families living in poverty may be less stable and unable to provide consistent opportunities for intellectual stimulation that might serve to offset some of the cognitive problems caused by the poisoning. Consequently, lead poisoning is especially harmful to poorer children
Grows at faster rate than any other part of the body
Two-year-olds have brains that are about three-quarters the size and weight of an adult brain.
By age 5, children’s brains weigh 90 percent of average adult brain weight.
In comparison, the average 5-year-old’s total body weight is just 30 percent of average adult body weight.
Interconnections allow for more complex communication between neurons, and they permit the rapid growth of cognitive skills
Corpus callosum, a bundle of nerve fibers that connect the two hemispheres of the brain, becomes considerably thicker, developing as many as 800 million individual fibers that help coordinate brain functioning between the two hemispheres.
At birth and continuing in preschool years, boys and girls show some hemispheric differences associated with lower body reflexes and the processing of auditory information.
Baron-Cohen argues that children with autism (who are predominately male) have what he calls an “extreme male brain.”
Extreme male brain, while relatively good at systematically sorting out the world, is poor at understanding emotions of others and experiencing empathy for others’ feelings. To Baron-Cohen, individuals with an extreme male brain have traits associated with normal male brain, but display traits to such an extent that their behavior is viewed as autistic.
Functional differences data suggest that there are minor structural differences between males’ and females’ brains. For instance, a section of the corpus callosum is proportionally larger in women than in men. Furthermore, studies conducted among other species, such as primates, rats, and hamsters, have found size and structural differences in the brains of males and females.
Myelination of the reticular formation , an area of brain associated with attention and concentration, is completed by the time children are about 5. This may be associated with children’s growing attention spans as they approach school age.
The improvement in memory that occurs during preschool years may also be associated with myelination. During the preschool years, myelination is completed in hippocampus, an area associated with memory.
Significant growth in nerves connecting the cerebellum , a part of brain that controls balance and movement, to the cerebral cortex , the structure responsible for sophisticated information processing. The growth in these nerve fibers is related to significant advances in motor skills that occur during the preschool years, as well as to advances in cognitive processing.
Preschoolers should eat a well-balanced diet containing the proper nutrients, particularly foods containing sufficient protein. (The recommended energy intake for children at age 24 months is about 1,300 calories a day, and for those aged 4 to 6, it is around 1,700 calories a day.) Although some fruit juice, such as a glass of orange juice with breakfast, is fine, generally juice has so much sugar that it should be avoided. In addition, keep offering healthy foods, even if children initially reject them; they may grow to like them.
Encourage preschoolers to exercise. Children who exercise are less likely to become obese than those who are sedentary.
Children should get as much sleep as they wish. Being run-down from lack of either nutrition or sleep makes children more susceptible to illness.
Children should avoid contact with others who are ill. Parents should make sure that children wash their hands after playing with other kids who are obviously sick .
Ensure that children follow an appropriate schedule of immunizations. Current recommendations state that a child should have received nine different vaccines and other preventive medicines in five to seven separate visits to the doctor.
Finally, if a child does get ill, remember this: Minor illnesses during childhood sometimes provide immunity to more serious illnesses later on.