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Nutrition for Nurses

8.1 The Impact of Nutrition on Endocrine Wellness Across the Lifespan

Nutrition for Nurses8.1 The Impact of Nutrition on Endocrine Wellness Across the Lifespan

Learning Outcomes

By the end of this section, you should be able to:

  • 8.1.1 Describe the impact of nutrition on the endocrine system during pregnancy.
  • 8.1.2 Describe the impact of nutrition on the endocrine system during infancy.
  • 8.1.3 Describe the impact of nutrition on the endocrine system during childhood.
  • 8.1.4 Describe the impact of nutrition on the endocrine system during adolescence.
  • 8.1.5 Describe the impact of nutrition on the endocrine system during adulthood.
  • 8.1.6 Describe the impact of nutrition on the endocrine system during later adulthood.

Pregnancy

A cascade of endocrine-related changes occurs during pregnancy. Many of these physiologic changes occur in the endocrine system (Figure 8.2) to prepare the pregnant individual for fetal growth and bodily changes during pregnancy. The placenta drives these changes by producing human chorionic gonadotropin (HCG) (Kepley et al., 2023). This hormone stimulates the corpus luteum to produce the progesterone necessary for growing and maintaining a fetus, and it changes the pregnant individual’s immune function to protect the fetus from immune rejection. HCG also stimulates the ovaries to increase estrogen and progesterone production until weeks 10–12 of pregnancy, when the maturation of the placenta is complete (Herrick & Bordoni, 2023). The placenta then takes over the production of those hormones throughout the pregnancy. In addition, the pregnant individual’s hypothalamus creates and releases thyrotropin-releasing hormone (TRH) to stimulate thyroid-stimulating hormone and prolactin from the pituitary gland (sometimes called the master gland).

A diagram of a human body shows the seven organs that make up the endocrine system. They include pineal gland, hypothalamus, and pituitary gland (all found in the brain); thyroid; adrenal glands; pancreas; uterus; ovaries; and testes.  Within the thyroid are the thyroid cartilage of the larynx, thyroid gland, parathyroid glands (on the posterior side of the thyroid), and trachea.
Figure 8.2 The endocrine system is made up of eight major glands: the adrenal glands, hypothalamus, pineal gland, pituitary gland, pancreas, ovaries or testes, thyroid gland, and parathyroid glands. (credit: modification of work from Anatomy and Physiology 2e. attribution: Copyright Rice University, OpenStax, under CC BY 4.0 license)

The placenta increases TRH, thus stimulating the pituitary gland, which then increases thyroid-stimulating hormone (TSH), a hormone that triggers secretion of thyroid hormones by the thyroid gland. Thyroid hormone production increases by 50% throughout pregnancy (Singh & Sandu, 2023). These hormones include triiodothyronine (T3) and thyroxine (T4), which regulate weight, energy levels, and metabolism. The influx of thyroid hormones is required for fetal brain development and thyroid function (Kepley et al., 2023). The parathyroid gland (Figure 8.3) secretes parathyroid hormone (PTH) to generate and maintain sufficient calcium levels for fetal growth (Hysaj et al., 2021). PTH allows adequate calcium absorption during pregnancy by maintaining ionized blood calcium phosphate levels by monitoring extracellular calcium concentrations (a lower calcium concentration triggers the release of PTH). Other functions of PTH include conserving calcium, decreasing phosphate reabsorption, and stimulating vitamin D production needed for the intestinal absorption of calcium. Vitamin D deficiency in pregnant clients is associated with elevated PTH levels (Hysaj et al., 2021). PTH concentration during the first trimester is in the lower normal range, but during the pregnancy, PTH levels increase to reach mid-normal range by the third trimester (Hysaj et al., 2021). The pituitary gland increases by approximately 136% because of lactotroph hyperplasia, which results in an influx of prolactin (Nana & Williamson, 2022). Prolactin levels increase by 10 times during pregnancy to promote breast tissue development for later milk production.

The corpus luteum and placenta release a peptide called relaxin, which affects the connective tissue in the body. It has several effects in pregnancy (Kepley et al., 2023). Relaxin softens the birth canal, supports growth of mammary glands, and prevents premature uterine contractions. Relaxin also facilitates the release of nitric oxide, which promotes systemic vasodilation resulting in decreased maternal blood pressure. In addition to the changes caused by relaxin, cortisol levels increase during pregnancy, which is vital for fetal brain development (Kepley et al., 2023). However, excessively elevated glucocorticoid levels impair neurodevelopment in the fetus. To combat pain during labor, endorphin and enkephalin levels increase.

A diagram of the parathyroid glands show the small, oval shaped glands located next to the thyroid glands in the neck. They are below the cricoid cartilage.
Figure 8.3 The parathyroid glands are small oval glands located next to the thyroid gland in the neck. (credit: modification of work from Anatomy and Physiology 2e. attribution: Copyright Rice University, OpenStax, under CC BY 4.0 license)

Impact of Nutrition on the Endocrine System During Pregnancy

Nutrition during pregnancy is vital for the health of both the pregnant client and the fetus. Normal hormonal changes cause disruptions in the pregnant individual’s body, and nutritional requirements change throughout the pregnancy with the need to support the nutrition of both the client and the fetus. A balanced diet, micronutrients, and intake of omega-3 fatty acids promote a healthy pregnancy during hormonal changes. To prevent a vitamin D deficiency, the National Institutes of Health (2022c) recommends a daily intake of 15 mcg during pregnancy and lactation.

Pregnancy requires proper nutrient-rich foods to support optimal endocrine function and ensure the health of both the pregnant client and the fetus (Jouanne et al., 2021). The pregnant client needs carbohydrates to fuel the increased energy demands of the growing fetus (U.S. Department of Agriculture, 2020). These carbohydrates support proper hormone production, including insulin, which regulates blood glucose levels. The growing fetus needs adequate protein to develop and to produce hormones. Healthy fats play a role in hormone synthesis, fetal development, and absorption of fat-soluble vitamins (Jouanne et al., 2021). Table 8.1 lists macronutrient intake ranges for the pregnant client. A registered dietitian specializing in prenatal nutrition can guide the pregnant client to support the fetus, client, and the endocrine function of both.

Macronutrient Percentage of Total Daily Calories Food Sources
Complex carbohydrates 45–65% Whole grains, fruits, and vegetables (preferred carbohydrate source)
Protein 10–35% Lean meats, poultry, fish, eggs, legumes, and dairy products
Healthy fats 20–35% Avocados, nuts, plant-based oils, fatty fish, flaxseed, and walnuts
Table 8.1 Macronutrient Intake to Support Pregnant Client and Fetus (sources: Jouanne et al., 2021; U.S. Department of Agriculture, 2020)

Pregnancy Complications: Hyperemesis Gravidarum

Some pregnant clients experience hyperemesis gravidarum, a condition during pregnancy characterized by extreme, persistent nausea and vomiting. Although the exact cause is unknown, genetic predisposition and hormonal and gastrointestinal changes may play a part. The hormonal change theory involves the dramatic increase in HCG because some correlational studies show elevations in HCG with hyperemesis gravidarum. Estrogen is also believed to be a contributing factor. As estrogen levels rapidly increase, so does vomiting. Estrogen-containing medications are known to cause nausea and vomiting as a side effect, which supports this theory. Lower esophageal sphincter relaxation during pregnancy is the basis for the gastrointestinal change theory. Even though the basis for this theory is structural, hormones still play a role. It is theorized that the increased levels of progesterone and relaxin hormones circulating in the bloodstream contribute to the relaxation of the lower esophageal sphincter. The lower esophageal sphincter closes to prevent acid from traveling back up the esophagus, as occurs during acid reflux. However, the relaxin hormone limits the functionality of the esophageal sphincter, contributing to heartburn.

Hyperemesis gravidarum complicates pregnancy because it can prevent the client and fetus from absorbing vital nutrients. Nutritional recommendations for a client with hyperemesis gravidarum include switching the prenatal vitamins to folic acid supplements only and the inclusion of a ginger supplement. There is limited research on diets changes that can minimize nausea and vomiting during pregnancy. One correlational study found fewer symptoms among women who consumed vegetables, fruits, and beans or legumes. However, women with elevated HCG levels in the same study who consumed increased amounts of processed white bread had a higher incidence of hyperemesis gravidarum (Tan et al., 2021).

Pregnancy Complications: Gestational Diabetes

Pregnant clients may have preexisting diabetes (either type 1 or type 2) or may develop diabetes during pregnancy, which is known as gestational diabetes (GD). GD is a disorder that occurs as the result of changes caused by human placental lactogen, a hormone that helps regulate insulin secretion, which leads to dysfunction or delayed response of the beta cells to blood glucose, thereby producing glucose intolerance (Quintanilla Rodriguez & Mahdy, 2022; Rasmussen et al., 2020). Other hormones associated with GD include corticotropin-releasing hormone and progesterone because these hormones are associated with insulin resistance and elevated blood glucose levels. These changes typically occur around the 24th to 28th week of pregnancy, with some individuals having complete resolution after childbirth. However, clients who experience GD have an increased risk for type 2 diabetes later in life.

Risk factors for GD include obesity, family history, a history of GD with previous pregnancy, polycystic ovary syndrome, and high-risk race or ethnicity (Quintanilla Rodriguez & Mahdy, 2022). A recent study of live births in the U.S. found that the rates of gestational diabetes among pregnant women with their first live birth increased across all race and ethnicity groups between 2011 and 2019 (Shah et al, 2021). However, rates were significantly higher among most non-Hispanic Asian and Hispanic/Latina subgroups compared to non-Hispanic White individuals.

Special Considerations

Greater Risk for Gestational Diabetes

In the U.S., American Indian and Alaska Native (AI/AN) women have higher rates of GD compared to non-Hispanic white women (Stotz et al., 2021). A recent study found AI/AN women were aware of the role of nutrition for maintaining a healthy weight during pregnancy and decreasing the risk for type 2 diabetes, but they were not aware that these principles could be applied to reduce their risk for GD. These findings highlight the need for culturally relevant diet instruction and interventions to address this disparity.

Nutritional considerations are the main factors for glucose control (Rasmussen et al., 2020). Pregnant clients with GD should receive recommendations from their obstetrician and counseling from a registered dietitian and diabetes expert. The nurse maintains sacred relationships with their clients, and this opportunity gives the nurse an advantage in educating them on the correct micronutrient and macronutrient consumption before diabetes counseling occurs. Many clients believe that blood glucose is solely related to sugar consumption and do not understand that the body breaks down carbohydrates to glucose, thus affecting blood glucose levels (Chen et al., 2020; Rasmussen et al., 2020). In addition, when individuals consume insufficient carbohydrates and increase their fat intake, they can develop elevated levels of serum fatty acids. This increase in serum fatty acids results in increased insulin resistance as well as higher than expected fetal fat accumulation and infant adiposity (Rasmussen et al., 2020).

Low-glycemic, high-fiber foods such as vegetables, legumes, nuts, fruits, and whole grains are recommended (Rasmussen et al., 2020). Other healthy diet options include lean proteins such as chicken, turkey, and salmon (which contains omega-3 fatty acids) and healthy fats such as avocados and nuts. Pregnant clients also need to consider portion control when consuming carbohydrates. The California MyPlate for Gestational Diabetes provides a visual example of recommendations for the pregnant client (California Department of Public Health, 2018). Pregnant clients should consume the recommended amounts of folic acid, vitamin D, iron, and calcium. Currently, there is no evidence to suggest that taking additional amounts of these micronutrients affects GD (Rasmussen et al., 2020).

The glycemic index is a system that ranks carbohydrate-containing foods based on their ability to raise blood sugar levels quickly or significantly (Rasmussen et al., 2020). Different carbohydrates vary in their ability to raise blood sugar levels based on the chemical structure of the food and their digestibility and absorbability. The scale goes from 0 to 100, with higher values indicating faster and higher blood sugar levels. Although this tool is valuable, it does not consider the amount of carbohydrates consumed, only the number of carbohydrates per serving size. In contrast, glycemic load considers a food item’s glycemic index and total carbohydrate content. It accurately represents how specific foods in specific quantities affect blood sugar levels.

Nurses should instruct clients to consume foods on the lower end of the glycemic index spectrum because these foods will help them manage their blood glucose properly. Nurses should also advise clients to check the glycemic load before consuming a meal to know how those foods will impact their blood glucose. Pregnant clients with GD also need to be advised on the frequency and consistency of meals. Three main meals and 2 or 3 smaller meals or snacks eaten at the same time each day are recommended to avoid excessive food intake and ensure steady blood glucose levels throughout the day. Rasmussen et al. (2020) suggest carbohydrate intake at breakfast of 30 g maximum (equivalent to 2 slices of bread or 1 bowl of cereal), based on limited research that shows elevated blood glucose levels in the morning.

Unfolding Case Study

Part A

Read the following clinical scenario and then answer the questions that follow. This case study will evolve throughout the chapter.

Sarah goes to the laboratory before her 24–28-week check for her oral glucose tolerance test (OGTT). Her results show an elevated level, indicating a need for further testing, so a second OGTT is ordered for confirmation. Following the second OGTT, Sarah is diagnosed with GD. Sarah is referred to a registered dietitian who specializes in GD. Sarah and the dietitian develop a personalized meal plan:

  • Morning: 30 g of carbohydrates—2 slices of toast with poached eggs
  • Snack: a serving of vegetables and hummus
  • Lunch: 60 g of carbohydrates—sandwich on whole grain bread with lean shredded chicken and vegetables such as lettuce; she eats a serving of fruit such as an apple, and drinks mainly water
  • Snack: ¼ cup of almonds
  • Dinner: Lean protein with vegetables and 60 g of brown rice

Sarah is taught to monitor her blood glucose levels and to engage in some physical activity. Her health care provider started her on a low dose of 500 mg metformin twice daily. Her subsequent examination will occur at 32 weeks’ gestation. The nurse encourages Sarah to call the office if she has any questions or concerns before her next appointment and to adhere to the treatment plan. The nurse also encourages her to communicate openly with her health care team throughout the pregnancy.

1.
The consumption of which nutrient should Sarah most closely monitor to manage her blood glucose levels?
  1. Water
  2. Fats
  3. Proteins
  4. Carbohydrates
2.
The nurse asks Sarah about her protein intake. Sarah reports that she has been regularly craving and eating cheeseburgers. Why should the nurse be concerned about this finding?
  1. Sarah is not choosing lean protein sources.
  2. Sarah is eating too much cheese.
  3. Eating a lot of red meat can indicate anemia.
  4. This is not a concerning finding as long as Sarah is consuming adequate amounts of food.

Chronic Pregnancy Complications: Thyroid Disease

Thyroid hormones change during pregnancy, especially when the pregnant individual already has a chronic thyroid condition (National Institute of Diabetes and Digestive and Kidney Diseases [NIDDK], 2017; Singh & Sandhu, 2023). Long-term thyroid disorders such as hypothyroidism (the thyroid gland does not produce enough thyroid hormone) or hyperthyroidism (the thyroid gland produces and excretes too much thyroid hormone) require careful management and oversight during pregnancy to ensure proper fetal growth and overall well-being of both the pregnant client and fetus. Proper thyroid hormone levels ensure the baby’s brain and nervous system develop correctly. As previously discussed, during normal pregnancy T4 levels remain unchanged; during hypothyroidism, T4 levels register as low, and TSH levels elevate as the pituitary gland attempts to trigger the thyroid to release more T4. Sometimes, T4 can remain within normal limits, and only TSH is elevated (NIDDK, 2017; Singh & Sandhu, 2023). Some signs of hypothyroidism include exhaustion, cold intolerance, muscle cramps, constipation, and memory or concentration problems.

The goal of treatment during pregnancy is to maintain maternal hyperthyroidism at the expected upper limits using the lowest effective prescribed dose of medication while avoiding fetal hypothyroidism. The treatment modality remains based on the etiology of hyperthyroidism. Graves’ disease is treated with antithyroid, beta blockers, and surgical interventions while monitoring for gestational thyrotoxicosis during pregnancy.

Nurses must remain cognizant of nutritional recommendations as they develop teaching and discharge plans. Nutritional recommendations for pregnant clients include sufficient iodine intake. Good nutritional sources of iodine include dairy, seafood (watch out for elevated mercury–seafood options), eggs, meat, and poultry (NIDDK, 2017; U.S. Food and Drug Administration, 2023). Iodine is added to table salt and to some prenatal vitamins. Nazeri et al. (2021) found that iodine supplementation can improve iodine levels in pregnant individuals, but the effects on the fetus have not yet been established.

Safety Alert

Mercury Consumption

Pregnant individuals need to be aware of mercury consumption during pregnancy. Mercury is a toxic metal with serious adverse effects for the developing nervous system. Fish containing high levels of mercury include shark, swordfish, and king mackerel; fish with low levels mercury include salmon, trout, and shrimp (U.S. Food and Drug Administration, 2023).

Unfolding Case Study

Part B

Read the following clinical scenario and then answer the questions that follow. This case study is a follow-up to Case Study Part A.

Sarah delivers a baby girl at 38 weeks’ gestation weighing 9 lb 1 oz. Sarah followed the recommendations of her nurse, dietitian, and health care provider, and her blood glucose levels are now at baseline pre-pregnancy levels. Because Sarah is at increased risk for developing type 2 diabetes, her nurse needs to incorporate this information into Sarah’s postpartum education.

3.
Sarah asks if her diabetes will recur now that she is no longer pregnant. How should the nurse respond?
  1. “You need to be monitored 6 weeks after delivery for the signs of diabetes.”
  2. “Now that you are no longer pregnant, your diabetes has resolved and is no longer an issue.”
  3. “Having gestational diabetes increases your risk for developing type 1 diabetes later.”
  4. “Having gestational diabetes increases your risk for developing type 2 diabetes later.”
4.
The nurse reviews diet strategies with Sarah to decrease her risk for developing type 2 diabetes. Which of the following statements indicates additional instruction is needed?
  1. “I will limit my intake of concentrated sweets.”
  2. “I will avoid eating nuts.”
  3. “I will try to eat different fruits and vegetables.”
  4. “I will incorporate protein into my meals and snacks.”

Infancy

The endocrine system undergoes extensive development during infancy. The hypothalamus and pituitary gland’s primary function encompasses controlling and releasing hormones that regulate growth and metabolism. These two glands are in the brain and mature during infancy to allow for appropriate hormone secretion. Growth hormone encourages growth and development. Growth hormone is at a high level during infancy and contributes to rapid developmental alterations during the first year of life (Murray & Clayton, 2022). The thyroid gland produces the hormones triiodothyronine (T3) and thyroxine (T4), which are required for cellular proliferation and differentiation, energy balance, cardiovascular physiology, and overall growth and development.

During the first few weeks of life, infants use hormones acquired from their mothers via the placenta until their thyroid gland takes over hormone production and secretion. The adrenal glands (located above the kidneys) produce cortisol and aldosterone. Cortisol regulates metabolism, the stress response, and immune function, and aldosterone maintains salt and fluid balance (Kiebzak et al., 2021). Insulin and glucose are hormones regulated by the beta cells in the pancreas. Infants remain sensitive to insulin, which allows for glucose stability. As with the other endocrine glands, the pancreas continues its development during infancy, and hormonal regulation and overall control continue to mature throughout infancy.

Macrosomia refers to a newborn who is significantly larger than average for their gestational age (Akanmode & Mahdy, 2023). This condition is seen more frequently in infants whose mothers are obese, had GD, or had a postdate pregnancy (Akanmode & Mahdy, 2023). Sustained elevations in a pregnant client’s blood glucose levels transfer through the placenta to the fetus, resulting in fetal hyperglycemia. This causes hyperplasia of the beta islet cells in the infant’s pancreas, leading to overutilization of glucose and storage by the fetus, resulting in increased fetal weight (Akanmode & Mahdy, 2023). Other factors affecting the fetus with fetal hyperglycemia include fetal adiposity and hyperinsulinemia.

Impact of Nutrition on the Endocrine System During Infancy

Blood glucose problems take the form of neonatal hypoglycemia or hyperglycemia. The definition of hypoglycemia is a blood glucose level at or below 40 mg/dL in the first 4 hours of life and a level below 45 mg/dL between the 4th and 24th hours (target level is 90–100 mg/dL; Kurtoglu et al., 2019; Rozance, 2023). Clients experiencing hypoglycemia during these time frames are categorized as having transient neonatal hypoglycemia. Hypoglycemia that persists longer than 60 minutes despite medical interventions is referred to as prolonged hypoglycemia.

Hypoglycemic conditions can develop among infants in the following situations: small for gestational age, sepsis, asphyxia, premature birth, transient hyperinsulinemia, diabetes during pregnancy, intrauterine growth restriction, toxemia, and increased metabolic requirements. The signs and symptoms in a newborn include tremors, irritability, diaphoresis, tachypnea, decreased sucking ability, and high-pitched cry leading to lethargy, hypertonicity, convulsions, and coma.

When treating hypoglycemia, oral feedings are preferred. However, if the infant is unable to take an oral feeding, or if no improvement occurs after 30 minutes, then 2 mL/kg 10% dextrose is given intravenously over 1 min; if the infant has a seizure, 4 mL/kg should be given. Subsequently, glucose is given intravenously at 6–8 mg/kg/min (Kurtoglu et al., 2019). Discontinue intravenous glucose supplementation and resume solely oral feedings after clearance by the pediatrician or neonatologist.

Hyperglycemia in a newborn refers to a blood glucose level greater than 125 mg/dL or a plasma glucose level greater than 150 mg/dL (Kurtoglu et al., 2019). Before the development of the pancreas and beta cells, the insulin receptors are not mature, and insulin production and secretion remain low. Neonatal hyperglycemia may be seen in preterm babies following bouts of hypoglycemia resulting from glucose and lipid infusion. Hyperglycemia increases the preterm infant’s susceptibility to infection, oxidative stress, bronchopulmonary dysplasia, prolonged hospitalization, retinopathy, and mortality (Kurtoglu et al., 2019). Continuous monitoring remains important during this situation. Treatment includes decreasing the rate of glucose administration and adjusting the rate of insulin administration to keep the plasma glucose level between 150 and 200 mg/dL (Kurtoglu et al., 2019).

Clinical Tip

Macrosomia

Infants with macrosomia require lab work and close monitoring after birth for respiratory and metabolic issues. Clinical evaluation of the infant’s respiratory effort following delivery is vital because meconium aspiration (when the newborn breathes in a mixture of stool and amniotic fluid during delivery) and transient tachypnea are more frequently seen in infants with macrosomia. Blood work should also be drawn immediately after delivery. These infants are at risk for hypoglycemia, hypocalcemia, hypomagnesemia, increased bilirubin (due to increased hemolysis and inefficient enterohepatic circulation), and polycythemia.

Childhood

A child’s growth, health, and development depend on a functioning endocrine system. The hormones act as chemical messengers to control physical functions and physiologic development, including growth, metabolism, sexual development, and other physical functions. As children undergo critical and rapid alterations, the main hormonal signals are sent from the hypothalamus and the pituitary gland. These two endocrine organs stimulate the production and release of specific hormones that target the other endocrine glands.

A child’s endocrine system goes through many phases as it is stimulated during the growth and development of the thyroid, adrenal glands, pancreas, and gonads (testes in males and ovaries in females). The hormones are necessary for optimal development as the child prepares for puberty (a stage of development in which sexual maturation and reproduction capabilities refine and mature). The pituitary gland produces growth hormone, which plays an integral role in the child’s growth. Insulin-like growth factors (IGF) play a role in mediating growth hormones; both growth hormone and IGF are peptide hormones that effect growth, maintain bone mass, and aid in cellular differentiation (Caputo et al., 2021).

Growth hormone and IGF promote bone and tissue growth, adequate nutrients, and hormone balance, which all play integral roles in overall growth and development across the lifespan (Caputo et al., 2021). Without IGF, the utilization of nutrients at the cellular and tissue levels would be compromised. Growth hormone and IGF maintain a correlational relationship with insulin secretion, leading to the possibility that growth hormone and IGF affect carbohydrate metabolism (Caputo et al., 2021). IGF enhances insulin sensitivity because it prompts glucose uptake.

Dietary guidelines for this age group recommend plant-based fiber because it incorporates amino acids that impact nutrient metabolism and absorption. Protein (lean meat and dairy products) and amino acids are essential for healthy growth and development because they play an anabolic role similar to that of growth hormone and IGF. The recommendation is 5–20% for children ages 2–3 and 10–30% for older children and adolescents (U.S. Department of Agriculture, 2020).

Impact of Nutrition on the Endocrine System During Childhood

Children are not immune to endocrine dysfunction. The nurse must recognize that proper balanced nutrition is vital in supporting optimal endocrine function and development in children and across the lifespan. Children require balanced nutrition to support the production and regulation of hormones (Caputo et al., 2021; U.S. Department of Agriculture, 2020). Proteins are the building blocks of neurotransmitters and hormones. Amino acids used to construct proteins stimulate growth hormone and IGF secretion.

A balanced diet includes a wide selection of nutrient-rich foods. When children do not get the proper nutrition they need, they may be diagnosed with failure to thrive, meaning their weight gain is significantly below that of other children of the same age and sex. A mix of fruits and vegetables, whole grains, lean proteins, and healthy fats encourages growth, development, and proper endocrine function (Caputo et al., 2021). The U.S. Department of Agriculture recommends that children consume 2 or 3 servings of vegetables per day, 2 or 3 servings of fruit, 3 servings of dairy products, 4–6 oz of lean proteins per day, and limited sugary, processed, and fried foods (Figure 8.4). Fruits and vegetables provide many anti-inflammatory and vital vitamins and nutrients for proper endocrine function. Diets high in protein increase growth hormone and IGF secretion levels, ensuring adequate growth (Caputo et al, 2021). Protein comes from lean meats, poultry, fish, eggs, dairy, legumes, and plant-based protein sources such as tofu.

A dessert cup filled with yogurt, granola, and honeydew, with the melon cut into the shape of evergreen trees. A plate contains flower-shaped pieces of cantaloupe and watermelon that have a single raspberry or blueberry as the flower’s center. Two slices of whole grain toast have a circle of chocolate spread to make a teddy bear face, using banana slices for ears and a nose and blueberries for the eyes.
Figure 8.4 A breakfast that includes fruits, whole grain, and dairy can be fun and encourage children to meet recommended daily nutritional guidelines. (credit: “Breakfast for kids: ‘Berry Bears’” by Ritas Safo/Flickr, Public Domain)

Healthy fats include avocados, seeds, nuts, and plant-based oils. These fats aid in hormone production and remain a supportive element of brain development.

Carbohydrates should be mainly whole grains, such as oats, brown rice, whole wheat bread, and quinoa. Refined sugars and processed foods should be avoided. These recommended carbohydrate options allow for slower energy release and limit blood glucose spikes while providing sustained energy. Children need micronutrients such as calcium, vitamin D, iron, zinc, selenium, and iodine for proper endocrine health. These micronutrients are found in a variety of fruits and vegetables. These recommendations are designed for the general population, but clients diagnosed with a medical condition may need a referral to a registered dietitian. The National Institutes of Health Office of Dietary Supplements provides recommendations on micronutrient intake by age.

Childhood Obesity and Malnutrition

Obesity in childhood is common, occurring in approximately 17% of youth ages 10–17 (Robert Wood Johnson Foundation, 2023). Although such children look overnourished, the opposite is true (Kobylinska et al., 2022). Malnutrition occurs when the body either does not receive sufficient nutrients or is unable to absorb essential nutrients. The individual’s body composition changes, and functions are impaired (Kobylinska et al., 2022). Obesity and malnutrition share a paradoxical relationship. Although obese children receive an abundance of calories, these calories may lack essential nutrients to promote daily performance, encourage proper growth and development, and encourage overall bodily homeostasis. Moreover, the child with obesity cannot fully absorb the essential nutrients because of systemic inflammation (Kobylinska et al., 2022).

Malnutrition in children with obesity may result from poor dietary choices (nutrient-poor foods), sedentary lifestyles, socioeconomic factors (limited access to healthy and wholesome foods), or lack of nutritional education. These children are at increased risk for developing chronic diseases such as type 2 diabetes, cardiovascular disease, and metabolic syndrome. Addressing this condition requires the collective efforts of family, caregivers, health care providers, nurses, dietitians, and communities.

Childhood: Precocious Puberty

Precocious puberty, also known as early development of secondary sexual characteristics, begins before the age of 8 years in females and 9 years in males (Breehl & Caban, 2023). Precocious puberty may be caused by many different endocrine-related factors, including obesity (Soliman et al., 2022). Several correlational studies show high-caloric intake with early puberty onset (Soliman et al., 2022). For example, excessive weight or obesity in childhood has a correlational relationship with the development of precocious puberty (Chen et al., 2017). The mechanism of the link between obesity and precocious puberty is still under investigation.

Adolescence

Many changes occur within the endocrine system during adolescence. As puberty progresses in adolescence, sexual maturation and reproduction capabilities refine and mature; these capabilities define puberty (Breehl & Caban, 2023). The primary physiological function of puberty is the production of mature adults capable of sexual reproduction. Hormonal changes trigger the onset of puberty, which occurs between the ages of 8 and 13 years in females and 9 and 14 years in males. The physical changes associated with puberty in females include breast development, menarche, and growth of pubic and axillary hair. In males, the changes include genitalia development, voice deepening, increasing height, and growth of pubic hair.

The endocrine glands involved in puberty include the hypothalamus, pituitary gland, adrenal glands, ovaries, and testes. All of the hormones affect nearly every organ system in the body. For example, in the musculoskeletal system, the muscles grow; the circulatory and respiratory systems see rapid growth. The nervous system is influenced by hormonal changes as well. The increase in estrogen and testosterone affects the limbic system through receptor binding, stimulating the sex drive and increasing the emotional roller coaster (Breehl & Caba, 2023). Children might undergo these changes earlier in life (precocious puberty) or experience delayed puberty (after age 13 in females or age 14 in males).

Impact of Nutrition on the Endocrine System During Adolescence

Nutritional recommendations are crucial for adolescents transitioning from childhood into sexual maturity (Soliman et al., 2022). The rapid changes and increasing energy demand for protein and micronutrients remain necessary for growth and development during this stage of life. Food insecurity, obesity, and body dysmorphia prevent this age group from getting the necessary nutrients. Evidence-based data supporting dietary recommendations for adolescents going through puberty are limited (Soliman et al., 2022). The Dietary Guidelines for Americans 2020–2025 recommend 3 servings of vegetables, 2–2½ servings of fruits, 7–10 servings of grains, 3 servings of dairy products, and 5–7 oz of lean protein (such as chicken, poultry, and seafood) per day (U.S. Department of Agriculture, 2020). The recommendations also include limiting fried, fatty, and processed foods.

The nurse should perform a thorough nutritional assessment by asking the adolescent client about their favorite foods, the foods they consume both at home and when they are with their peers, the number of servings of nutrient-dense foods they eat each day, and ways that social media may be influencing their dietary habits. Adolescents who do not consume enough nutrient-rich foods may be at risk for deficiencies of iron, folate, vitamin B6, and vitamin B12, which might delay their growth and development, as well as puberty.

Adulthood

The human body in adulthood continues to rely on the homeostasis, metabolic requirements, development, and reproduction function that the endocrine system provides through the secretion of hormones (Campbell & Jialal, 2022). Physiologic changes continue as adolescents transition into young adults and then into adulthood. These changes include peak physical growth; sexual maturation; brain development; and reproductive, metabolism, and hormonal stability. Women stop growing earlier than men do, between 20 and 35 years of age, whereas men continue to grow into adulthood and reach peak physical strength and stamina between 30 and 40 years of age.

Adults also reach sexual maturation. Sexual maturation and reproductive system markers include regular menstrual cycles for females and peak testosterone production for males. Secondary sexual characteristics such as breast development in females and facial hair growth in males reach full development. Growth hormone continues to play a role in adulthood, as male skeletal growth is typically completed during this stage of life. Growth hormone contributes to muscle growth, repair, and maintenance. Thyroid hormones, including T4 and T3, play a role in metabolism, heart function, and energy regulation. Insulin regulates blood glucose levels; during adulthood, nondiabetic adults respond effectively to the insulin their bodies produce, allowing them to fully use the carbohydrates consumed and aid in the metabolism process.

As in all stages of life, the body continuously attempts to achieve homeostasis. This hormonal balance is crucial for overall health, reproductive function, mood regulation, and metabolism. Hormonal changes vary based on individuals’ genetics, lifestyle, and overall health. Nutrition integrates within the system to help it reach homeostasis.

Nutrition plays a pivotal role in the health of adults for optimal endocrine function and prevention of endocrine dysfunction (Caputo et al., 2021). The role of healthy nutrients includes overall health and endocrine disorder prevention; energy-based performance; weight management; bone, mental health, and cognitive function; healthy aging; and disease management and healing. A balanced diet includes whole grains, lean protein, fruits, vegetables, healthy fats, and water. Micronutrient foods include antioxidant-rich foods, containing vitamins A, C, D, zinc, iodine, selenium, iron, and magnesium, which decrease inflammation and the inflammatory process, containing vitamins A, C, D, zinc, iodine, selenium, iron, and magnesium. Foods that contain these important micronutrients include leafy green vegetables, citrus fruits, berries, nuts, seeds, lean meats, fatty fish, dairy, and whole grains. The nurse should advise individuals to avoid processed and refined sugary foods and beverages to encourage optimal endocrine function. Heavily processed foods contribute to inflammation, insulin resistance, and hormonal imbalances.

Later Adulthood

Age-related changes affect every endocrine organ (van den Beld et al., 2018). As the function of the organ system begins to decline with age, other factors, such as inflammation and caloric intake, play a role in endocrine function. A study by van den Beld et al. (2018) found that regular aging changes were associated with an increase in the concentration of serum thyroid-stimulating hormone (TSH); but alterations in TSH concentration remained dependent on iodine status. T3 blood concentrations fluctuate depending on the individual. The overall decline in thyroid hormone activity resulted from hormone metabolism changes, inflammation, and energy restriction. Further research is needed to develop age-specific hormone reference ranges to guide health care providers in hormone replacement therapy (van den Beld et al., 2018).

The hypothalamic–pituitary–somatotropic axis remains responsible for growth hormone secretion into the blood from the pituitary gland (van den Beld et al., 2018). Average age-related growth hormone secretion decline is called somatopause. Somatopause is associated with adipose tissue increase and leads to the decline of growth hormone and insulin-like growth factor after puberty.

Undernutrition occurs as normal aging brings appetite suppression and limited food intake (Molfino et al., 2021; van den Beld et al., 2018). The endocrine system plays a role in appetite suppression and anorexia. Hormonal changes include increases in cholecystokinin, leptin, and cytokines and a decrease in ghrelin. Appetite suppression in older adults revolves around the increase in levels of cholecystokinin. Nurses and health care providers combat cholecystokinin with an antagonist to stimulate the appetite and increase nutritional consumption. Frail older adults can experience diminished leptin levels, while healthy older adults can have increased concentration levels of circulating leptin (van den Beld et al., 2018). Aging is also associated with glucose intolerance, elevated insulin levels, and vitamin and mineral deficiencies.

For older adults, consuming enough protein to minimize age-associated loss in muscle mass is important. The recommendation for protein intake includes 23–31 oz per week at the minimum or 35% of total calories (Molfino et al., 2021; U.S. Department of Agriculture, 2020). Continuous anorexia in frail older adults negatively impacts their body composition; to combat this problem, early nutritional intervention improves outcomes and quality of life (Molfino et al., 2021). Like all age groups, older adults should strive to choose nutrient-rich foods. The ability to absorb Vitamin B12 decreases with age and the use of certain medications, so ensuring adequate intake of this vitamin is of particular concern (U.S. Department of Agriculture, 2020).

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