8.1 The Impact of Nutrition on Endocrine Wellness Across the Lifespan

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.

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.

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.

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.

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).

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.

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.

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.