Proper nutrition is incredibly important all throughout a person’s life. As life progresses, nutritional needs and challenges can change dramatically. All of these changes, however, are linked throughout a human’s lifecycle. For instance, not getting enough calcium as an infant could eventually result in brittle bones or osteoporosis as an adult. For this reason, it is important to study the nutritional needs of all ages, and to be aware of the nutritional deficiencies that all people may face at some point in their lives.

Infants, children, adolescents, adults, and the elderly have similar basic nutritional needs, but at each time of life there are specific issues that affect nutritional requirements (eg, pregnancy and breastfeeding).

Nutrition in Pregnancy and Lactation

A woman’s nutritional needs increase during times of pregnancy and while breastfeeding. It is important for a woman to be in good health prior to and during pregnancy. The way to that optimal health is through good nutrition. It is recommended that a woman of normal weight at the beginning of pregnancy consume an extra 150 to 200 calories per day during the first few months of pregnancy. The recommended amount increases to about 300 extra calories per day during the third trimester and during lactation. Caloric intake beyond an extra 300 calories is not necessary in most cases and can result in excessive weight gain.

The global recommendation for at least five servings of fruits and vegetables, along with whole grains, protein, and low-fat dairy products applies during pregnancy and lactation as well. In addition, pregnancy and lactation increase the need for some nutrients, the most important of which are folic acid, iron, calcium, vitamin D, and protein.

A deficiency of folic acid can result in neural tube defects (eg, spina bifida) in the fetus. Sufficient folic acid is critical for at least three months before conception and during pregnancy and lactation; the recommendation is for 800 mcg. During pregnancy, a deficiency of iron, which is the most commonly deficient nutrient in the United States, can lead to underweight or preterm babies. For pregnancy, the recommendation is 27 mg per day; while breastfeeding, 10 mg per day. Calcium and vitamin D, which work together, are necessary for proper bone development of the fetus. Pregnant women over age 19 need 1,000 mg of calcium per day; under age 19, it increases to 1,300 mg per day. The recommendation for vitamin D is 600 International Units (IU) per day. Protein, of course, is necessary for the building of tissues in the fetus as well as for maintaining the mother’s body tissues; about 71 grams per day is recommended during both pregnancy and lactation. A deficiency of zinc also can lead to health problems for the infant. 

Infant and Childhood Nutrition

Infants and children must consume sufficient nutrients to sustain their growth. The rate of growth can vary considerably from one infant to another, but generally infants are expected to double their birth weight in six months and triple it in twelve months. For most infants, breastfeeding alone until four to six months of age will provide all the nutrients needed. Pediatricians recommend that infants begin receiving solid foods starting around four to six months of age.

When solid foods are introduced at around four to six months of age, one food at a time should be introduced with a period of about seven days between each food introduction. Introducing foods in this way will make it easier to identify possible food allergens. Certain foods that tend to cause allergies should not be given to infants; these include eggs, nuts, and shellfish. Honey should not be given to infants under one year of age because it can contain a botulism toxin that is not harmful to adults but can cause problems in infants.

Premature infants may need more supplementation than those born at full term; iron is one nutrient that may need to be supplemented earlier in premature infants. An infant receives enough iron from his or her mother during the last three months of gestation to last until about four months old. If an infant is born preterm, he or she may not have had the time needed in the womb to receive enough iron stores.

Prematurity can affect the nutritional status of an infant. An infant born prematurely may not have developed enough of a sucking reflex to breastfeed properly; yet breastfeeding, if possible, is the ideal for any infant whether premature or not. This problem can be overcome by pumping breast milk and feeding it to the infant with a bottle to ensure that it gets enough nourishment; at the same time, the infant should be breastfed as much and as often as possible to encourage development of the sucking reflex.

Failure to Thrive describes a situation when a child’s or an infant’s rate of weight gain is significantly less than normal. There can be wide variations in the rates of children’s growth, but with Failure to Thrive, usually the weight is below the third percentile in growth charts. If the condition is short-term and is treated, the child will develop normally. If Failure to Thrive lasts for a long time, however, normal growth and development will be affected. There can be many reasons for Failure to Thrive, including medical problems or environmental causes, which lead to psychosocial problems. Some of the medical reasons may include chromosome abnormalities, endocrine or central nervous system problems, and gastrointestinal problems. Environmental problems may be poor eating habits, poverty, emotional deprivation, and caregivers’ ignorance of proper feeding. If caregivers’ ignorance is a factor, nutritional education of the caregivers is necessary. 

Healthy food requirements for children are basically the same as for adults. Since children are growing, they may need more energy foods than adults do; however, those energy foods should be from healthy sources of food such as whole grains, fruits and vegetables, dairy, and protein. Childhood obesity is a widespread problem related to the consumption of high-fat and high-sugar convenience foods plus lack of regular exercise among children. It is estimated that one in three children in the United States is obese or overweight. The Department of Health and Human Services is attempting to address the epidemic of childhood obesity with educational and informational resources for parents.  

Issues in Adolescence

Adolescence, a period of roughly ten years from about age 11 to age 21, is a time of rapid growth. Infancy is the other time of life when growth is most rapid. In infancy, the growth is mainly physical, but with adolescence, there are rapid emotional and mental changes as well. It is during adolescence, particularly late adolescence, when the most bone mass is accumulated. It is estimated that 40% of total bone mass is accumulated during late adolescence. Studies suggest that if bone mass accumulation is not maximized during adolescence, it can lead to osteopenia and osteoporosis later in adulthood. 

For maximum bone accumulation, there must be sufficient calcium intake during adolescence. At present, the suggested level of calcium intake in adolescence is 1300 mg per day; that figure may increase in the near future. Many adolescents do not get enough calcium to ensure good bone mass levels. In addition, high-phosphate sugary soft drinks, which are popular with adolescents, work against the sufficient accumulation of calcium as bone forms.

Adolescence is a time of rapid emotional and physical change, when the body is changing from that of a child to an adult. The need for many nutrients increases during adolescence, but adolescence is also the time of life when eating disorders are most likely to appear. The rapid growth in adolescence with increased need for nutrients along with the extreme restriction of proper nutrients that the eating disorders produce can lead to severe consequences.   

Anorexia nervosa and bulimia nervosa are the two most common eating disorders seen in adolescence. These eating disorders are more common in female adolescents than in males, although there is some concern that they may be increasing among male adolescents. 

In anorexia nervosa, the individual severely restricts her food intake so that her weight drops to an unhealthy level. A sufferer of this condition has a distorted self-image; the adolescent believes that she is fat no matter how much weight she loses. Along with the severe weight loss, important macronutrients and micronutrients are missing and out of balance, which can lead to serious results—in extreme cases, even death. It is estimated that about 1% of the adolescent female population in the U.S. suffers from anorexia nervosa.

Bulimia runs a slightly different course. Binging and purging describes bulimia; the person regularly eats beyond satiation, then makes herself vomit or misuses laxatives to force her bowels to empty (purging). It is estimated that up to 20% of college-age females practice these techniques occasionally, but 2% to 4% engage in these activities regularly enough to meet the criteria for bulimia. While anorexics tend to be thin to the point of emaciation, bulimics often maintain a normal weight. The distorted self-image, however, is present in bulimia as in anorexia nervosa. 

Bulimia usually does not produce the extreme nutritional deficiencies that anorexia nervosa does, especially if the individual maintains a near normal weight. The psychological issues present in anorexia are also present with bulimia and must be addressed during treatment. In both conditions, the sufferers’ attitudes toward food are distorted, and treatment interventions must help them develop a more realistic and less obsessive attitude about food. The patient is not treated alone; interventions should include families and address family dynamics as well as focusing on the individual. This is true for both anorexia nervosa and bulimia.

There are oral signs that appear with bulimia. One oral sign of bulimia is a characteristic erosion of the lingual surfaces of the teeth, especially the maxillary teeth. This erosion is due to the acid produced by frequent vomiting. Other oral signs are cracked lips, irritation of the throat, and swollen salivary glands due to the acid reflux. If the enamel erosion is severe, restorations may protrude beyond the enamel surface. Patients may be suffering from pain in the oral cavity, which can make eating difficult and thus hamper recovery from either disorder. Dental professionals should be aware if these signs are present, question the patient carefully, and refer for treatment when necessary.  

For a patient who suffers from bulimia, there are suggestions that the dental professional can make to minimize the effects of vomiting. Rinsing with bicarbonate of soda as a mouthwash after vomiting will help neutralize the acids in the oral environment. Brushing immediately after vomiting episodes should be discouraged because brushing after vomiting can lead to abrasion. Fluoride treatments may be prescribed to help protect the teeth. 

Treatment for both anorexia nervosa and bulimia consists of a multi-disciplinary approach. The physical manifestations must be treated as well as the psycho-social aspects. At the root of these conditions are psychological issues that must be addressed. Treatment often continues for years into young adulthood. Relapses are quite common and patients are often resistant to treatment methods. The psychological and emotional issues can last into adulthood and can be very difficult to overcome.

Issues in Adulthood

Research over the past 60 to 70 years has challenged much of what was previously believed in the U.S. about diet and nutrition. The custom of three “square” meals a day, centered around meat, gravies, and heavy starches, has evolved into an emphasis on fruits, vegetables, and whole grains with some low-fat dairy as the basis for a healthy diet. The prevalence of obesity, diabetes, and heart disease today illustrates the problem that many still have not adopted the recommended changes in eating patterns. 

Recent and ongoing research studies are concentrating on the abilities of various types of food to prevent heart disease and cancer. Some results have suggested that certain foods play a role in prevention. Diets high in saturated fats are linked with high blood cholesterol levels, which are associated with heart disease. Studies have shown that diets containing more polyunsaturated fats, on the other hand, tend to lower the risk of heart disease. It is recommended that people limit saturated fats and increase their intake of polyunsaturated fatty acids like omega-3 fatty acids. This applies to everyone, but it is especially important for those who are at risk of heart disease.

Several foods have been linked with cancer prevention; garlic, red wine, and tea are a few. Foods high in anti-oxidants, calcium, and vitamins A, C, D, and E have also been the subjects of cancer prevention studies. Some studies have suggested that calcium and garlic, for instance, can help prevent colorectal cancer. Thus far, the research is inconclusive and more studies and clinical trials are needed to confirm the early results. At present, ingesting excessively high amounts of any of these substances or nutrients is not recommended (especially the fat-soluble vitamins A, D, and E). Even “good” nutrients like calcium can be toxic in very high doses. Supplements, while they may have a place for certain situations, are not a good replacement for nutrients that can be acquired through a varied diet. The best practice is to consume a varied diet centered on fruits, vegetables, and whole grains (the DASH diet is a good example), and to try to get as many nutrients as possible through diet rather than supplements.   

Proper nutrition is very important for healing after surgery or an injury. Poor nutrition can delay healing. For best results after surgery, health professionals now emphasize proper nutrition before as well as after a scheduled surgical procedure. Often, a dietician may be part of the surgical team, especially in cases where nutrition may be an issue (eg, chronic disease or alcohol abuse). In some cases, the surgical procedure may be postponed to give the patient—in concert with a health professional—time to get into a better health state. This is becoming a more common practice even in dental offices, especially periodontal and oral surgery practices. Some nutrients that have been suggested to directly affect wound healing include adequate protein, vitamins A and C, and possibly zinc.

A problem that has been receiving some attention recently is that of polypharmacy, which can be defined as prescribing or using several different drugs for different conditions. Polypharmacy generally applies to older adults, who may be more likely to have multiple health conditions and, therefore, several drug prescriptions. It can be a problem for younger adults as well. With polypharmacy, the interaction between the different medications can increase unwanted side effects, reduce the effectiveness of the medications, and even produce toxic effects. This becomes even more problematic if an individual is having prescriptions filled by multiple pharmacists. The different pharmacists may not be aware of all the medications being taken by that individual.

Nutritional Considerations in Aging

As people age, they experience changes that can affect their nutrient intake and how efficiently their bodies use nutrients. For instance, it is not unusual for an older person’s sense of taste and smell to diminish, which can lead to loss of interest in food and eating. This can become a vicious cycle because a lack of certain nutrients (eg, zinc) can affect a person’s sense of taste and smell, so the reduction in intake of nutrients further exacerbates the reduced taste sensations.

Xerostomia (ie, dry mouth) is another condition that is often found in the older population. Xerostomia is most often a side effect of medications, especially medications for hypertension and other conditions that affect older individuals. Autoimmune conditions, cancer, and cancer treatments can also cause this condition. A person’s sense of taste can be affected, and xerostomia can also be associated with changes in both the hard and soft oral tissues. Caries susceptibility increases with the condition, and soft tissue lesions and cracked lips can be found in individuals who are experiencing severe xerostomia. The discomfort and pain associated with the soft tissue lesions can make eating uncomfortable, which can lead to nutritional deficiencies.

Some suggestions that the dental professional can make to help reduce the effects of xerostomia include: sipping water often; Biotene products for dry mouth; artificial saliva products; using an alcohol-free mouthwash (there are many on the market today); and avoiding dry or chewy foods. Pilocarpine can be prescribed to help reduce xerostomia. Often a patient who is experiencing this condition will suck on hard candies or chew gum to stimulate saliva production. In such situations, suggest using candies and gum that are sweetened with xylitol instead of sugar. 

Gastrointestinal function generally does not change greatly in healthy elderly individuals because of the large functional reserve that is present in the gastrointestinal tract. Nevertheless, there are some gastrointestinal changes that accompany aging. Diverticulitis affects more than 50% of people over age 70, but not all experience symptoms. The digestive process tends to slow down in older individuals; as a result, about 35% of individuals over the age of 65 experience some constipation. Stomach and colon cancer rates increase in the older population.

Some studies have shown that nutritional status declines in the elderly due to gastrointestinal changes. This seems to be more of a problem in the elderly who live in care settings or are hospitalized. Declining nutritional status seems to be associated with factors other than gastrointestinal changes alone. Elderly people who feel isolated and who do not have much contact with others may suffer from depression or anxiety disorders. If they do not have help with meal preparation and other tasks, it can affect their nutritional health status.  

According to the American Psychological Association, elderly people generally are not as cognitively impaired as widely believed. There may be some slight decline, but usually it is not enough to affect daily living tasks. Also, according to the APA, six percent of older adults suffer from anxiety disorders, but depression is less prevalent among non-institutionalized older adults than it is in younger populations.

Research shows that aging has a significant effect on immunity, and that the immune response decreases as adults age. This decreasing immune response generally involves a diminishing production of T-cells because the thymus shrinks as an individual ages. This may be associated with the increased susceptibility to infection that some older people have. It may also play a role in the increased risk of cancer that is seen in the elderly.

Nutritional status has a definite effect on immune function, and many experts suggest that older adults take a vitamin/mineral supplement to increase immune function. Studies have shown that a nutritional supplement will increase the immune response and, therefore, improve the health of older adults. According to one study by the Council for Responsible Nutrition, many older adults are deficient in vitamins D and E, calcium, folate, and several minerals. Supplementation with these nutrients increased the immune response in these older individuals.

Summary

Nutritional resources are available online to help people with nutrition questions and with tools for ensuring that they get adequate nutrition in their diets. The Food and Nutrition Center, a division of the U.S. Department of Agriculture, has a very useful website (http://fnic.nal.usda.gov/) with information and resources for consumers as well as for professionals. The website is user-friendly and contains helpful suggestions for healthy eating.