HLTH 213
Special Populations
Special Populations
I. Introduction
A. What are the special populations participating in sports?
1. Athletes' nutrition needs should be reviewed individually and unique nutrition plans developed for each athlete.
2. Some athletes may require special consideration when developing a nutrition plan because of unique medical situations, their age group, or personal food preferences.
3. Special populations discussed in this section
a. Athletes with diabetes
b. Athletes who are pregnant
c. Child and teen athletes
d. College athletes
e. Masters athletes
f. Athletes who are vegetarian
B. Each of these types of athletes require a different approach to nutrition and exercise planning to keep them safe and performing well in their sport.
II. What are the special considerations for athletes with diabetes?
A. Diabetes is a metabolic disorder that affects carbohydrate availability and utilization by the cells of the body. Because carbohydrates are one of the main sources of energy for the body, particularly during exercise, diabetes severely alters normal energy metabolism in the body. See the Quick Review of glucose metabolism (Figure 15.1).
1. Carbohydrates ultimately end up as glucose in the bloodstream.
2. Glucose transporters move glucose out of the blood and into cells.
3. Insulin (produced in the pancreas) affects the glucose transporters.
4. Insulin is released from the pancreas in response to postprandial glucose increases in the blood.
5. Insulin activates cell membrane transporters, thus increasing glucose transport into the cells. This reduces blood glucose levels back to normal.
6. In diabetes, insulin release by the pancreas is disrupted and/or cells have a decreased response of any insulin that is secreted, resulting in the inability of cells to uptake glucose.
7. Hyperglycemia (high blood glucose) is a result of decreased cellular uptake of glucose.
8. When glucose levels remain high, the cells are robbed of energy. The body thinks it's starving because glucose cannot get into the cells for energy production, so the liver starts to release more glucose. Additionally, fat and protein reserves (muscle) start to break down to produce more glucose.
9. All of these changes result in increases of blood glucose levels and consequent symptoms of diabetes.
B. Main types of diabetes
1. Type 1: The pancreas stops producing insulin and exogenous insulin injections are required. Approximately 5 to 15% of people with diabetes have type 1 diabetes.
2. Type 2: The pancreas produces sufficient amounts of insulin, in fact it may actually overproduce insulin, but the body's cells are not responsive. Approximately 85 to 95% of people with diabetes have type 2 diabetes.
3. Prediabetes is a condition in which blood glucose levels are elevated but not high enough to meet the criteria for a diagnosis of diabetes. A blood glucose level between 100 to 125 mg/dL is considered prediabetes.
C. What are the considerations for exercise for people with diabetes?
1. Regular exercise is recommended to help control blood glucose levels in individuals with both type 1 and type 2 diabetes.
2. Exercise can be considered part of treatment for type 2 diabetes because it can decrease glucose levels in individuals who still produce some insulin. It can also produce weight loss.
3. Regular exercise helps reduce cardiovascular disease risk, which is higher in any individual with diabetes.
4. Careful planning of food intake and insulin injections is necessary for athletes with type 1 diabetes who exercise.
Author Note: Ask students to visit the website ( of the Diabetes Exercise and Sports Association (DESA) for excellent information on athletes competing at high levels with diabetes, as well as facts about exercise and diabetes. This nonprofit organization is dedicated to encouraging active lifestyles for people withdiabetes.
D. Management of diabetes for athletes
1. Controlling diabetes within the normal blood glucose range of 70 to 100 mg/dL is the primary goal of any individual or athlete with diabetes. Regular blood sugar levels within this range help athletes avoid the two most common and dangerous medical conditions: hypoglycemia and hyperglycemia.
2.Self-monitoring of glucose: Athletes must self-monitor regularly to know how their glucose levels respond to exercise.
a. Urine glucose testing: Tells the athlete if glucose is spilling over into the urine. It is not as helpful to athletes as blood glucose testing.
b. Blood glucose testing: Uses a portable device to get an actual blood glucose reading. The level of blood glucose prior to exercise will tell the athlete if it is safe to start exercise or if food intake, insulin injections, or exercise avoidance are indicated.
c. Testing for ketones: This should be done before exercise if blood glucose is greater than 250 mg/dL.
d. Table 15.2 discusses exercise safety as it relates to glucose and ketone monitoring.
3. Nutrition recommendations for athletes with diabetes: Consultation with a Certified Diabetes Educator (a Registered Dietitian with experience in diabetes education), in collaboration with the athlete's physician, is critical to controlling blood glucose levels on a daily basis as well as before, during, and after exercise.
a. Follow the basic recommendations of the MyPyramid system.
b. 45 to 60% of total calories should come from carbohydrates.
c. Balance carbohydrate intake (starch, fiber, and sugars) throughout the day. It is more important to balance the total amount of carbohydrate in meals and snacks throughout the day rather than focusing on the type of carbohydrate.
d. Proteins should make up 15 to 20% of total daily calories.
e. Fat should make up less than 30% of total calories and less than 7% saturated.
4. Should athletes with diabetes eat during exercise? Athletes with type 1 diabetes who exercise longer than 30 minutes at a time should consume 15 to 30 grams of carbohydrates every 30 to 60 minutes during exercise. Sports drinks, sport gels, and sport bars can easily provide this amount of energy in convenient packaging.
E. Recognizing and managing diabetic emergencies
1. Any athlete with diabetes who takes insulin or oral medications should be aware of potential emergencies during exercise.
2. Hyperglycemia (high blood glucose) can occur when insulin is lacking. Insulin injections will be required to resolve this condition.
3. Hypoglycemia (low blood glucose) occurs when too much insulin is available. Consumption of carbohydrate is required to resolve this condition.
4. Table 15.3 reviews the signs and symptoms of hyper- and hypoglycemia.
5. Athletes with diabetes must be aware of these potential emergencies and have appropriate medications and carbohydrate foods on hand or readily available during exercise.
6. Athletes should also tell support staff (athletic trainers, coaches, teammates) that they have diabetes so they can call someone if help is needed.
Author Note: Have students review Table 15.3 and note that some hypoglycemia signs and symptoms are similar to those for hyperglycemia. Ask students what other information they can use to help the athlete with diabetes displaying some of these signs and symptoms.
III. What are the special considerations for athletes who are pregnant?
A. Pregnant athletes can continue to be active during all trimesters. Typically, competing while pregnant, especially in the last two trimesters is not recommended. Pregnant athletes should follow their physicians' advice about the type, amount, and intensity of exercise during pregnancy.
B. How are caloric requirements affected by pregnancy?
1. An additional 300 calories/day are needed during pregnancy. However, some research has shown that increased calorie needs may vary from 25 to 800 calories per day.
2. Some athletes may have had difficulty meeting pre-pregnancy calorie needs, and adding an additional 300 calories may be difficult.
3. Pregnant athletes reduce energy expenditure with declines in exercise duration and intensity, so meeting these additional calorie needs can be done with planning.
4. Development of meal plans with appropriate calories should be done on an individual basis for each pregnant athlete.
C. Pregnant athletes at risk for not meeting calorie, and thus weight gain, requirements
1. Weight classification sports
2. Those who were trying to lose weight prior to pregnancy
3. Athletes with disordered eating
4. Consequences of inadequate calorie intake include poor fetal growth and development, fatigue, and inability to exercise
D. How are the athletes' protein requirements affected by pregnancy?
1. Protein needs increase slightly during pregnancy.
2. An additional 20 to 25 grams per day is needed.
3. Consume additional protein in nutrient-dense food sources (dairy, lean meat, high-protein beans, and legumes).
4. Consequences of inadequate protein intake during pregnancy include decreased muscle mass for the mother and decreased immune function of the mother, which in turn affects fetal development.
E. How are carbohydrate and fat requirements affected by pregnancy?
1. Carbohydrate needs as a percent of calorie intake are the same as for nonpregnant athletes (50 to 65%).
2. Fat intake is also consistent with the nonpregnant state (20 to 35%).
F. Do pregnant athletes require more vitamin B?
1. Folate or folic acid is necessary for fetal development of the nervous system.
a. Inadequate folate intake within the first month of pregnancy has been shown to increase the risk of neural tube defects in the fetus.
b. Folate needs increase from 400 to 600 micrograms/day for pregnant women.
c. Women of childbearing age should consume adequate amounts of folate regularly and continue consumption of high-folate foods during pregnancy.
2. Vitamin C requirements increase from 70 mg to 80 to 85 mg/day during pregnancy. This small increase can usually be met through intake of foods high in vitamin C, such as orange juice, which is also high in folate.
3. Vitamin A requirements increase from 700 to 750–770 micrograms/day. Vitamin A aids in immune functions and cell differentiation. Pregnant women should avoid vitamin A supplements and consume good vitamin A food sources.
4. Magnesium requirements increase by 40 mg/day during pregnancy. Food sources of magnesium are generally protein foods; meeting protein needs often ensures that magnesium needs are met as well.
5. Iron needs increase substantially for pregnant athletes; 27 mg/day during pregnancy (compared to 18 mg/day for nonpregnant state). Iron is often part of prenatal vitamins, but consuming high-iron food sources throughout pregnancy is important.
IV. What are the special considerations for child and teen athletes?
Author Note:In this book, a child athlete is considered to be 9–18 years of age.
A. Assessing growth and maturation in child and teen athletes
1. The growth and maturation of child and teen athletes can be assessed with CDC growth charts and BMI charts. CDC growth charts are used to identify growth patterns as the child ages by comparing the child with his or her peers, or the "norm." Children past the age of 2 usually maintain their height and weight growth between the same percentiles (such as 50th and 75th) during preschool and early childhood. This consistent height-to-weight growth pattern is often referred to as the growth channel. It is cause for investigation if the child falls above or below his or her established growth channel.
2. Teen and adolescent growth
a. Growth may fall dramatically outside the growth channel during adolescence.
b. Growth spurts occur during puberty, which occurs between the ages of 10-1/2 to 11 years in girls and 12-1/2 to 13 years in boys.
c. During puberty, sexual maturation characteristics occur [development of sexual organs, pubic hair, breast tissue (girls), deepening of voice (boys)]
3. Overexercise in youngsters may affect adult stature.
a. Growth of the skeleton is complete with the closure of epiphyses.
b. Short stature at maturation usually means short adult stature.
c. Energy intake must meet energy needs for continued growth and maturation.
d. Dietary restriction, especially at the time of puberty, may restrict growth and decrease intake of minerals essential to bone growth.
B. Nutrition for the child and teen athlete
1. To support growth, young athletes need adequate
a. Calories
b. Protein
c. A variety of nutrients
2. Use the MyPyramid food system as a guide for food choices within the food categories.
3. Allow flexibility in calorie intake based on growth spurts (increased calorie needs) and lulls. Let the child eat based on hunger.
4. Encourage children and teens to eat at regular intervals throughout the day to maintain energy levels.
5. A nutrient-dense snack before and after practice will provide energy and extra nutrients.
6. Parents and caregivers play a pivotal role in good nutrition for child and teen athletes.
Author Note: Ask students to come up with reasons why child athletes may not be consuming enough calories to meet growth and maturation needs.
C. Do fluid needs for child athletes differ from those for adult athletes?
1. Children are less heat tolerant, produce more heat during exercise, and sweat less during exercise.
2. Volitional fluid intake is likely to be lower in children.
3. Tips for encouraging child athletes to adequately hydrate
a. Offer sweet-tasting or flavored beverages (sports drinks).
b. Have frequent fluid breaks for the whole team.
c. Give each child his or her own sport bottle filled with the amount of fluid necessary for that exercise session.
d. Coaches, parents, and team support staff should all encourage fluid breaks for young athletes.
D. Do young athletes require higher vitamin and mineral intake?
1. Young athletes who meet energy needs and continue growing at an adequate pace generally will meet most vitamin and mineral needs.
2. Calcium and iron are the two minerals that are likely to be deficient in the diets of young athletes, especially pubescent girls.
3. Calcium requirements for males and females aged 9 to 18 is 1,300 mg/day (compared with 1,000 mg/day for adults). Calcium is essential for healthy bone growth and achieving peak bone mass.
a. Child athletes should consume at least three servings in the milk/alternative group each day.
b. Child athletes should also consume other calcium sources, such as calcium-fortified orange juice, fortified breads, and cereals.
4. Iron is necessary for growth of muscle and bone.
a. Food sources rich in iron include fortified cereals, breads, and sport bars.
b. A multivitamin/mineral supplement may help children meet their iron (and calcium) needs; however, only one multivitamin/mineral should be consumed each day to avoid reaching the UL levels for these minerals.
V. What are the special considerations for college athletes?
A. Are college athletes' energy needs higher than pre-college? College athletes have nutrition requirements typical of any adult athlete. The unique aspects of college life can affect nutritional intake and status in the college athlete population.
1. Energy demands of training are likely to increase in college.
2. Fewer days off, more intense training, and increased strength and conditioning training all increase energy needs.
3. If strength and conditioning training is greater than before college, muscle mass will likely increase, therefore energy needs will also increase.
4. More intense and demanding off-season training will keep energy needs high.
5. Increased energy demands can be met through increased intake of food and nutrient-dense fluids.
6. Eating in residence halls offers a variety of food selections, usually in buffet style and all-you-can-eat settings. (See Andre's Meal Plan in Training Table 15.3.)
B. Practical meal planning for college athletes
1. College may be the first time athletes are making all of their own food choices.
2. These choices include when to eat, how much to eat, and what types of foods to consume. Some college athletes will eat in dorm cafeterias, others prepare their own foods in apartments, and some have access to team training tables in the evenings. Meal planning is similar in each of these situations.
3. Breakfast is important. College athletes can eat portable, quick breakfasts before morning workouts or when rushing to early classes (samples in text).
4. Lunch and dinner are important. It is important not to skip meals and to consume several food groups during each meal (see the quick meal tips in Table 15.6).
5. Shopping for food is as important as preparing and consuming the actual meals. What the athlete brings home from the grocery store is what he or she will consume. Table 15.7 provides a grocery list for college athletes.
C. How does alcohol consumption affect college athletes' nutrition? Alcohol consumption on college campuses is of great concern to administrators. Some of this concern is related to parties or tailgates prior to and celebrations after sporting events.
1. The incidence of alcohol consumption among college athletes is surprisingly high.
2. Most research is on binge drinking, which is the consumption of 4 or more drinks in one episode by women, and 5 or more drinks for men.
3. In one study, 50% or more of college athletes, both male and female, reported a binge drinking episode within a 2-week period prior to the survey. Though many college athletes do not drink alcohol at all, those who do often drink large amounts.
4. Alcohol contains 7 calories/gram and is metabolized for energy and/or stored as body fat.