ch9 - basic nutrition factors in health Flashcards
when would CSCS provide nutrition advice vs dietitian?
CSCS = sports and performance; dietitian = medical condition / nutrition therapy
what is the first step in nutrition coaching?
defining the athlete’s goals and identifying the coach’s goals (since the two may be different)
sports dietitian takes into account what factors for plans?
(1) the appropriate calorie level; (2) macronutrients and micronutrients in recommended amounts; (3) adequate fluids and electrolytes; and (4) supplements as necessary to help correct a nutrient deficiency, make up for potential nutrient shortfalls, or meet training goals
an example of nutritional diversity/synergy?
eating an orange, an apple, and a pear provides a broader array of essential nutrients than is provided by three apples
vegans are vulnerable to deficiency of what vitamin?
B12
what are DRIs?
created by the Food and Nutrition Board, Institute of Medicine, National Academies, they are a complete set of nutrient intakes for use when evaluating and planning diets for healthy individuals based on literature regarding nutrient intake and the reduction of chronic disease, as opposed to simply prevention of dietary deficiencies
how does a dietitian evaluate daily intake?
looks at several days worth of food records to get an idea of intake for each nutrient; esp. true with intake of nutrients found in few foods
AI?
adequate intake, the average nutrient intake recommended when RDA can’t be established
UL?
tolerable upper intake level, the max avg daily nutrient level not associated with adverse health effects. (UL represents intake from all sources including water.)
EAR?
average daily nutrient intake level considered sufficient for half of healthy population with each life stage and sex
what groups have high prevalence of inadequacy of vitamin E and magnesium?
all subgroups (males and females in all age groups)
best source of vitamin E?
oils, nuts, and seeds
best source of magnesium?
nuts and seeds (pumpkin seeds, almonds, cashews) and beans, incl. mung beans and lima beans
what groups have adequate fiber and potassium?
individuals under the age of 2; all other groups are below DRI
what are nutrients of concern according to the 2015 dietary guidelines advisory committee?
fiber, potassium, calcium, and vitamin D
sources of calcium?
dairy foods, fortified beverages (soy drinks, orange juice), and canned sardines
sources of vitamin D?
fatty fish, fortified beverages. and fortified yogurt
sources of B12?
animal foods, fortified nutritional yeast, fortified cereals. beef, lamb, veal, and fish are some of best sources.
why are adults over the age of 50 are encouraged to consume foods fortified with synthetic vitamin B12?
vitamin B12 absorption is affected by insufficient hydrochloric acid in the stomach, found in about 10-30% of older adults
functions of dietary protein?
growth and development of cells, repair of cells, use as enzymes/transport carriers/hormones
what elements are proteins composed of?
carbon, hydrogen, oxygen, and nitrogen. “amino” means “nitrogen containing.”
how many amino acids are there total?
20
what is the protein reserve of the body?
50% skeletal muscle, 35% visceral tissues such as liver and kidney in the bones, 15% skin and blood (and other structural tissues)
what meal changes do vegans need to make?
compound mixing; mix legumes, vegetables, seeds, nuts, rice, and whole grains
RDA of protein for men and women >19 or older?
0.80 g per kg
what groups have higher dietary protein RDA?
children, teens, and pregnant/lactating women
how much protein can be metabolized as a source of energy when person is in calorie deficit?
only 1-6% in most circumstances but up to 10% during prolonged exercise in glycogen depleted state
the acceptable macronutrient distribution range (AMDR) for protein in children 1yr - 3yr is what?
5% to 20%
the acceptable macronutrient distribution range (AMDR) for protein in children 4yr - 18yr?
10% to 30% of total calories for children 4yr to 18yr
the acceptable macronutrient distribution range (AMDR) for protein in adults over 18yr is what?
10% to 35% of total calories
how do protein requirements change when calories are lower?
1% for every 100-calorie decrease below 2000 calories.
why are protein intakes too high above recommended levels not recommended?
carb and fat intake may be compromised
other than fruit, what foods is fructose found in?
honey
how much insulin secretion does fructose have?
less insulin secretion than other sugars
how does galactose form lactose?
combines with glucose to form lactose
what are the disaccharides?
sucrose, lactose, maltose. they are two simple sugar units joined together. sucrose (table sugar) is most common one.
where is sucrose found?
naturally in most fruits and is crystallized from sugar cane syrup and sugar beets to make brown, white, or powdered sugar.
where is lactose found?
mammalian milk.
maltose (glucose + glucose) occurs when?
primarily when polysaccharides are broken down during digestion. also occurs during fermentation; it’s the primary carb in beer.
what do polysaccharides contain?
thousands of glucose units. some of the most important: starch, fiber, and glycogen.
what is starch?
the storage form of glucose in plants. grains, legumes, and vegetables. (starch must be broken down into glucose to be used.)
what are the physiological effects of fiber?
they have different physiological effects; some may delay gastric emptying, which = greater fullness; others increase bulk and water content, reducing constipation and decreasing transit time of poop. some soluble fibers decrease absorption of cholesterol and may therefore help to reduce blood cholesterol after ingestion.
what do prebiotic dietary fibers do?
act as fertilizer for gut bacteria; legumes/beans/peas, oats, bananas berries, asparagus, garlic, and onions are this
fiber-rich foods?
beans, peas, bran, many fruits and vegetables, and some whole-grain foods.
what are the options when glucose enters the muscles and liver?
(1) metabolized for energy (2) synthesized to form glycogen
where is glycogen stored in the body?
3/4 of glycogen in the body is stored in skeletal muscle; remaining 1/4 is stored in liver
what is conversion of glucose to glycogen called?
glycogenesis.
GI is ranked according to glucose rise in what time period compared to a reference food (typically white bread or glucose)?
2 hours
how does insulin helps lower blood glucose?
by facilitating glucose transport into cells
the fate of glucose in the body depends on what?
where it’s shuttled; muscle cells use glucose for energy while fat cells convert glucose into triglycerides (fat)
what are the issues with GI?
(1) published values for GI may vary considerably due to differences in testing and variations in ingredients used, ripeness of food, method of food processing, cooking, and storage; (2) consuming carbs as part of a meal or in different quantities affects the GI; low GI generally includes vegetables, legumes, beans, and whole grains
what is the dietary requirement for saturated fatty acids?
the body can make these fatty acids; therefore there is no dietary requirement for saturated fatty acids
what are the essential polyunsaturated fats?
omega-6 and omega-3, necessary for: healthy cell membranes, proper development and functioning of brain/nervous system, hormone production
sources of omega-6?
soybean, corn, safflower oil
sources of omega-3?
fish (halibut, herring, salmon, trout, mackerel)
polyunsaturated oils?
soy, corn, sunflower, safflower
monounsaturated oils?
olive, peanut, canola
saturated oils?
coconut, palm kernel
a severe loss in body fat might affect what vitamins?
A D E K as they are fat-soluble vitamins
what are the three stages of iron deficiency?
depletion, marginal deficiency, and anemia
anemia develops when?
low iron stores persist for a period of time and the body cannot make enough healthy red blood cells to deliver oxygen throughout the body
general symptoms of iron deficiency?
weakness, fatigue, irritability, poor concentration, headache, decreased exercise capacity, hair loss, dry mouth, feeling cold, inflamed tongue, shortness of breath, and pica (desire to eat substances such as dirt/ice)
populations at risk for developing iron deficiency anemia?
distance runners, vegetarian athletes, female athletes, those who lose a significant amount of blood during their menstrual cycle, people who take excessive amounts of antacids, and people with certain digestive diseases such as celiac disease
what is heme iron?
derived from hemoglobin; fond in foods that originally contained hemoglobin and myoglobin (e.g. red meats, fish, and poultry)
what is nonheme iron?
found in all other non-meat foods incl. vegetables, grains, and iron-fortified breakfast cereal
what are the absorption differences between heme and nonheme iron?
heme iron is absorbed better than nonheme iron, and unaffected by other foods. we absorb about 15-35% of heme iron we eat, but only 2% to 20% of nonheme iron
what factors affect absorption of nonheme iron?
tannins, calcium, polyphenols, phytates, and some soy protein person can increase absorption of nonheme iron by consuming vitamin C rich foods or beverages at the same time nonhem esource is consumed, or pairing nonheme with heme (e.g. spinach with meat). magnesium and calcium may interfere with iron absorption, yet many americans do not get these through diet alone. due to this, only a doctor should recommend iron and how to take it.
how does low calcium put one at risk for bone damage?
it is pulled from its storage site in bone to meet the demands of the body and keep calcium concentrations in the blood, muscle, and intercellular fluids constant
AI (adequate intake) for water?
3.7L (125.1 fl oz) for men, 2.7L (91.3 fl oz) for women, 3L (101.4 fl oz) for pregnant women, 3.8L (128.49 fl oz) for lactating women
what athletes have greater dehydration risk?
american football players (partic. linemen) have greater dehydration risk. “backs and receivers, with an average body mass of 93± 6 kg (204.6 ± 13.2 pounds), lost an average of 1.4 ± 0.45 L (47.3 ± 15.2 fluid ounces; or approximately 6 ± 2 cups) of sweat per hour”; “linemen, with an average body mass of 135.6 ± 17 kg (298 ± 37.4 pounds), lost an average 2.25 ± 0.68 L (75.1 ± 1.5 fluid ounces; approximately 9 cups) of sweat per hour during practice.)”
how should athletes measure water loss?
weigh in minimal, lightweight clothing, after drying off and urinating, immediately before and after their workout; sweaty clothes should be removed; each pound (0.45 kg) lost during practice represents 16 ounces (0.5 L) of fluid. 2% or more = not enough hydration.
what is the equation for sweat rate?
(preexercise body weight) + (fluid intake during exercise) - (postexercise body weight) - (urine produced)
foods that can complicate urine color, making it a poor hydration indicator?
beets, blackberries, certain food colors, and medications can turn urine pink, red, or light brown; B vitamins, carotenoids (such as beta carotene), and some medications can turn urine dark yellow, bright yellow, or orange, while artificial food colors (such as those found in some sport drinks) may also turn urine blue or green
major electrolytes lost from sweat?
sodium chloride (majority), potassium, much less: magnesium, even less: calcium in that order
an athlete with headaches, nausea, vomiting, muscle cramps, swollen hands and feet, restlessness, and disorientation might need to consume what?
sodium, as these are the side effects of hyponatremia (low sodium) below 125 mmol/L
an athlete with risk of developing cerebral edema, seizures, coma, brain stem herniation, respiratory arrest, and risk of death might have what nutritional deficiency?
hyponatremia (low sodium) below 120mmol/L
what populations have greater dehydration risk?
sickle cell traits, cystic fibrosis, people in hot/humid places, people in high altitude
functions of cholesterol?
production of bile salts, vitamin D, and several hormones, including the sex hormones (estrogen, androgen, and progesterone) as well as cortisol
nutritional risk factors for heart disease?
high levels of total cholesterol, low-density lipoproteins (LDL), and triglycerides
athletes who consume saturated fat should limit it to what percent of calories?
less than 10% of total calories – and replaced with unsaturated fat, particularly polyunsaturated fat
an athlete should max out sugar at what calorie percentage?
maximum 10% of total calories
how many calories are stored within the fat tissue of a lean runner who is 160 pounds (72 kg) with 4% body fat?
approximately 22,400 calories
how do athletes benefit from consistent aerobic training?
increases the muscle’s capacity to use fatty acids
how do athletes benefit from low-carb diets?
body adapts to using more fat when high-fat low-carb diet is consumed over a period
what is the definition of a vitamin?
organic substances needed in very small amounts to perform specific metabolic functions
why is carb consumption important when ingesting B vitamins?
they help make energy from metabolism of carbs
A / D / E / K: commonality?
fat soluble
beta carotene, alpha carotene, or beta cryptoxanthin are confused for vitamin A why?
they are converted into vitamin A in the body
side effects of excess A?
liver damage, intracranial pressure, dizziness, nausea, headaches, skin irritation, pain in joints and bones, coma, and death
side effects of excess vitamin D?
heart arrythmia and too-high blood calcium, which can cause blood vessel and tissue calcification as well as damage to heart, blood vessels, and kidneys
functions and side effects of vitamin E?
function: acts as a coagulant and thins blood. sides: high E levels are associated with hemorrhagic stroke, particularly in people taking blood thinners
side effects of excess vitamin K?
can pose risk to people taking anticlotting medications
functions of minerals?
contribute to the structure of bone, teeth, and nails; they are a component of enzymes; they perform a wide variety of metabolic functions
function of iron?
essential for “functioning and synthesis of hemoglobin, a protein that transfers oxygen throughout the body”; also myoglobin, which transports oxygen to muscles; also for growth, development, cell functioning, and the synthesis/functioning of some hormones
if you took a random sample of the female population, what percent would be deficient in iron?
16% of teenage girls aged 16 to 19 and 12% of women aged 20 to 49
how many female athletes test positive for iron deficiency?
in female aerobic endurance athletes, more than one in four women tested positive
primary and secondary functions of water?
PRIMARY FUNCTION OF WATER: lubricant, shock absorber, building material, and solvent. OTHER ESSENTIAL FUNCTIONS: body temperature regulation (through sweat), nutrient transport, waste product removal, maintaining fluid balance and therefore normal blood pressure
an athlete exercising in a hot environment would adapt to heat stress how?
greater sweat volume, lower electrolyte concentration of sweat, lower temperature for the onset of sweating
why do the elderly have greater risk of dehydration?
age-related declines in fluid intake and changes in water conservation
why do children have greater risk of dehydration?
(1) increased heat gain from the environment due to greater surface area-body mass ratio compared to adults, (2) increased heat production during exercise, (3) decreased ability to dissipate heat through sweat, (4) decreased sensation of thirst compared to adults
risks of dehydration?
(1) increase core body temperature, (2) reduce stroke volume and cardiac output, (3) decrease blood pressure, (4) reduce blood flow to muscles, (5) increase heartbeat, (6) exacerbate symptomatic exertional rhabdomyolysis, (7) increase risk of heatstroke and death
ratio of sodium, potassium, and carbs for prolonged activity in hot weather, per liter?
20 to 30 mEq of sodium (460-690 mg with chloride as the anion) per liter, 2 to 5 mEq of potassium (78-195 mg) per liter, and carbohydrate in a concentration of 5% to 10%
ingesting multiple carbs (e.g. glucose, fructose, and maltodextrin) vs single carbs in drinks?
ingestion of multiple types of carbohydrate versus a single carbohydrate will lead to greater gastric emptying, carbohydrate absorption, oxidation, and possibly better performance
what temperatures should beverages be?
50-59 °F
water recommendations for children and adults during practice?
children weighing 88lb should drink 5oz of cold water or a flavored salted beverage every 20 minutes during practice; adolescents weighing 132lb drink 9oz even if they don’t feel thirsty
post-exercise, athletes should consume how much fluid with significant dehydration?
approximately 1.5 L (50 ounces) of fluid (with sufficient electrolytes) for each kilogram of body weight loss (0.7 L or 24 ounces for each pound of body weight)
a person wanting to lower cardiovascular disease risk by affecting blood lipids should follow what kind of diet?
higher protein low carb diets, esp. in obese individuals
why is protein important for bone development?
protein contributes 50% of bone volume and 33% of bone mass
how does protein intake affect calcium?
supplemental but not dietary protein increases calcium losses through urine, but 0.7g to 2.1g of protein per kg increase urinary calcium and intestinal calcium absorption
why would athletes with low protein need to worry about calcium levels?
low dietary protein intake suppresses intestinal calcium absorption
why is an athlete worried about protein excess misguided?
the excess nitrogen is excreted as urea in urine, and the remaining ketoacids are either used directly as sources of energy or converted to carbohydrate (gluconeogenesis) or body fat
what is the highest known protein intake that can be consumed without impaired renal function?
up to 2.8 g per kg
an athlete worried about eating complex carbs before exercise shouldn’t worry why?
little evidence supports thesis that consumption of low GI foods before exercise might spare carbs by minimizing insulin secretion.
glycemic load?
amount of carbs in a portion of food that influences glycemic response; a more realistic gauge than GI, which is based on standard serving size
how to calculate glycemic load?
(GI * [amount of carbs in a portion of the food]) / 100
side effects of diets low in fiber?
constipation, heart disease, colon cancer, and type II diabetes.
DRI fiber?
21-29g/day for women and 30-38g/day for men, based on age group.
how can carbs help endurance athletes?
carbs can improve time to exhaustion during aerobic endurance performance; high glycogen levels also spare the use of protein for fuel, thereby attenuating muscle breakdown
carb recommendations for aerobic endurance athletes training >90m or more per day at moderate (70-80% VO2) intensity?
8-10g of carbs per kg per day; athletes in high intensity intermittent activities such as soccer players also benefit from high carb diets
carb intake for athletes in strength, sprint, and skill activities?
5g to 6g per kg of carbs per day
within 30 minutes after aerobic endurance training, what is the ratio of carb to consume to quickly stimulate glycogen resynthesis?
approximately 1.5 g of higher-glycemic carbohydrate per kilogram of body weight
an athlete wants to consume less carbohydrate immediately post-exercise. how can they do this?
as long as they consume a higher-carbohydrate meal or snack at regular intervals (approximately every 2 hours) after finishing training.”
how can athletes who do not train every day can restore their glycogen over a 24-hour period?
consuming enough total carbs
what are in the category of lipids?
triglycerides (fats and oils) as well as sterols and phospholipids
what are the most significant lipids to nutrition?
triglycerides, fatty acids, phospholipids, and cholesterol
what are triglycerides and how do they relate to fat?
glycerol + three fatty acids (the term fat often refers to triglycerides)
why do fats provide more energy per gram than carbs and proteins?
while fat contains carbon, oxygen, and hydrogen atoms like carbs, fatty acid chains have more carbon and hydrogen relative to oxygen, so they provide more energy per gram
why are vegan athletes worried about omega 3 probably not going to get this from flax/walnuts/etc?
conversion process of epa to dha is inefficient (approx 5% of ALA is converted to EPA and 0.5% of ALA into DHA in adults)
