Chapter 17 - Nutrition Flashcards
What is nutrition?
- The process by which a living organism assimilates food and uses it for growth and repair of tissues.
Give some examples of nutrition topics of discussion for the fitness professional.
- Food preparation methods
- Food guidance systems (food guide pyramid, MyPlate)
- Healthy snacks
- Carbohydrate, protein, and fat basics
- Statistical information on the relationship between chronic disease and the excesses or deficiencies of specific nutrients
- Nutrients contained in foods or supplements
- Vitamins and minerals as essential nutrients
Importance of water and hydration status
What is a Registered Dietician (RD)?
- A specialized food and nutrition expert with extensive training who meets specified criteria
What are the educational and professional requirements for a registered dietician?
- Bachelor’s Degree from accredited college or university with coursework approved from the Commission on Accreditation for Dietetics Education (CADE)
- Supervised practice program: complete a CADE-accredited program (6-12 months in length) with focused practice and study in clinical and community nutrition, and food-service management (graduate study often combined)
- National examination: Must pass the exam in order to receive RD credential
- Continuing education: must complete CE requirements to maintain active RD credential
What is a calorie (with a lowercased “c”)?
- The amount of heat energy required to raise the temperature of 1 gram of water 1℃
What is a Calorie (with an uppercased “C”)?
- A unit of expression of energy equal to 1,000 calories. The amount of heat energy required to raise the temperature of 1 kilogram or liter of water 1℃
What is a kilocalorie?
- A unit of expression of energy equal to 1,000 calories. - The amount of heat energy required to raise the temperature of 1 kilogram or liter of water 1℃
What is total energy expenditure (TEE) / total daily energy expenditure (TDEE)?
- The amount of energy (calories) spent, on average, in a typical day
- TEE is the sum total of three different energy components:
- Resting metabolic rate (RMR)
- Thermic effect of food (TEF)
- Energy expended during physical activity
What is resting metabolic rate (RMR)? How much of TEE does it account for?
- The amount of energy expended while at rest; represents the minimal amount of energy required to sustain vital bodily functions such as blood circulation, respiration, and temperature regulation. (relative and constant)
- 70% of TEE in sedentary adults, but varies from person to person.
What are some factors that affect/determine RMR?
- Age
- Maintaining muscle mass is important during aging because some of the decline in RMR associated with age is caused by a decline of muscle
- Sex
- Genetics
- Hormonal changes
- Example: thyroid hormones influence many metabolic functions throughout the body including fat and carbohydrate metabolism and growth
- High concentrations tend to cause an increase in RMR
- Body size
- Body composition
- Temperature
- Altitude
- Illness
- Medication
- Food
- Caffeine take
- Cigarette smoking
What types of medication can affect RMR? Give examples.
- Certain cardiovascular medications can reduce RMR from 4% to 13%
- Chemotherapy can reduce RMR 6% to 11%,
- Long-term use of growth hormone increase RMR by 12%
- Thyroid medications used in hypothyroidism can increase RMR as much as 17%
What is basal metabolic rate? What can be interchangeably used with? How does it differ?
- A term used when the measurements are taken after the subject has spent the night in a metabolic ward or chambers and has fasted for 12 hours.
- Often used interchangeably with RMR, but RMR is measured after the subject spends the night at home and has to drive to the research lab for measurement
What is the thermic effect of food (TEF)? How much of the TEE does it account for? Give an example of how energy is expended via TEF.
- The amount of energy expended above RMR as a result of the processing of food (digestion) for storage and use.
- TEF typically accounts for approx. 6-10% of TEE
- Increased energy expenditure after a meal required to mechanically digest and move food through the digestive tract, transport nutrients from gut to blood, and distribute throughout body
Describe energy expended during physical activity. How much of TEE does it account for? What varies the results?
- The amount of energy expended above the RMR and TEF associated with physical activity
- Can be influenced more dramatically than RMR and TEF
- Physical activity accounts for ~20% of TEE.
- Varies based on an individual’s current fitness levels and the type, intensity and duration of physical activity or exercise
What is the most common way to Estimate Total Daily Energy Expenditure?
Step 1: Estimate RMR
Weight (lbs) x 10 = RMR
110 (lbs) x 10 = 1,100 RMR
Step 2: Multiply RMR by appropriate activity factor
RMR x activity factor = TEE
1,100 x 1.5 (activity factor) = 1,650 calories expended per day (TEE)
Even most commonly used formulas can have up to a __% variance in overestimating or underestimating RMR and TEE. US Department of Agriculture has online calculators to help estimate TEE.
20%
Describe physical activity factors for adults of average size 19 years or older who’s activity factor (range) is 1.2-1.3 (Sedentary Lifestyle).
- 1.2 - 1.3 activity Factor
- Very Light
- Seated and standing activities, office work, driving, cooking, no vigorous activity
Describe physical activity factors for adults of average size 19 years or older who’s activity factor (range) is 1.5-1.6 (Low-Active Lifestyle).
- 1.5 - 1.6 activity Factor
- Low Activity
- In addition to sedentary lifestyle activities, 30 minutes of moderate activity equivalent to walking 2 miles in 30 minutes
- Includes most office workers with additional planned exercise routines
Describe physical activity factors for adults of average size 19 years or older who’s activity factor (range) is 1.6-1.7.
- 6 - 1.7 activity Factor
- Active
- In addition to low active lifestyle activities, an additional 3 hours of activity such as bicycle 10-12 miles an hour, walk 4.5 miles an hour
Describe physical activity factors for adults of average size 19 years or older who’s activity factor (range) is 1.9-2.1.
- 1.9 - 2.1 activity Factor
- Heavy
- Planned vigorous activities, physical labor, full-time athletes, hard-labor professions such as steel or road workers
Define protein.
Amino acids linked by peptide bonds
What is protein’s primary function? What else is protein involved in?
- Primary function: to build and repair body tissues and structures
- Involved in the synthesis of hormones, enzymes, and other regulatory peptides
1 gram of protein yields how many calories?
4 calories
The structure of protein is approximately __ different amino acids linked together by peptide bonds to build many different proteins.
20 amino acids
Can essential amino acids be manufactured in the body in sufficient amounts? Where is it obtained?
- Cannot be manufactured in the body (or are manufactured in insufficient amounts)
- Must be obtained from the food supply or other exogenous source
How many essential amino acids are there?
- 8 essential amino acids
How does the body manufacture nonessential amino acids?
- The body is able to manufacture them from dietary nitrogen and fragments of carbs and fats
List the two semi-essential amino acids that cannot be manufactured by the body at a rate that will support growth, especially in children.
- Arginine
- Histidine
List the 8 essential amino acids.
- Isoleucine
- Leucine
- Lysine
- Methionine
- Phenylalanine
- Threonine
- Tryptophan
- Valine
List the nonessential amino acids.
- Alanine
- Asparagine
- Aspartic acid
- Cysteine
- Glutamic acid
- Glutamine
- Glycine
- Proline
- Serine
- Tyrosine
Proteins must be broken down into the constituent amino acids before the body can use them to build or repairs tissue or as an energy source.
The fate of proteins depends on the homeostatic needs of 3 major processes. What are they?
- Tissue replacement
- Tissue addition
- Need for energy
What happens to proteins once they reach the stomach?
Opens up ingested proteins strands (denatures or uncoils) with hydrochloric acid (HCI) and cleaves (with enzyme pepsin) strands into peptide chains
What happens to proteins once they reach the small intestines and interact with pancreatic and intestinal proteases (protein enzymes)?
Further splits peptide chains into
- Tripeptides
- Dipeptides
- Amino acids
Small intestine’s lining (absorptive cells)
- Splits tripeptides and dipeptides into amino acids
- Absorbs amino acids through the intestinal wall into the enterocytes and released into the bloodstream by the liver
Once in the bloodstream, the free-form amino acids can be used for what?
- Protein synthesis (building and repairing tissues or structures)
- Immediate energy or potential energy (fat storage)
If carbohydrate or total energy intake is too low, the body has the ability to use amino acids (from dietary or body proteins) to provide energy. Describe the process.
- Amino acids are first deaminated (or stripped of the amine group) allowing the remaining carbon skeleton to be used for the production of glucose or ketones to be used for energy
- The removed amine group produces ammonia (toxic) - Ammonia is converted to urea in the liver and excreted as urine by kidneys
What is considered a complete protein?
- If a food supplies all of the essential amino acids in appropriate ratios
What is considered an incomplete protein?
- If a food source is low or lacking in one or more essential amino acids
What is the limiting factor of an incomplete protein?
- The essential amino acids missing or present in the smallest amounts within a food source
Describe the process of protein synthesis regarding the limiting factor of protein absorption.
- All amino acids must be present at the site of protein manufacture or synthesis will be reduced to the point at which the cell runs out of the limiting amino acid
List the three terms used to rate dietary protein.
- Protein efficiency ratio (PER)
- Net protein utilization (NPU)
- Biologic value (BV)
What is biologic value (BV)?
- The measure of protein quality or how well it satisfies the body’s essential amino acid needs
What are the main sources for Complete Proteins? Give an example.
Animal sources:
- Dairy
- Meats
What are the main sources for incomplete proteins? Give an example.
Incomplete proteins:
- Grains
- Legumes
- Nuts: cashews, pumpkin seeds and other nuts
- Seeds
- Beans
- Lentils
- Barley, cornmeal, oats, buckwheat, pasta, rye, wheat
How can an individual who is vegetarian/vegan still put complete proteins in their body?
- Incomplete proteins can be combined to make available all of the essential amino acids and form a complete protein
Example: mixing grains, legumes, and seeds can create a complete protein
What is gluconeogenesis? How does it relate to a negative energy balance?
- When amino acids are used to assist in energy production
- Gluconeogenesis occurs during a negative energy balance
- Body-fat reduction requires caloric deficit creating a negative energy balance
The amount of lean body mass lost in a person in a negative energy balance can be reduced by increasing the amount of _______ in the diet, leading to a more rapid return to nitrogen balance.
- Increasing the amount of protein in the diet
Protein and the bodybuilder:
To reach competitive body-fat levels, calorie intake is continually _______ while exercise (such as cardiorespiratory training, weight training and posing) is _________.
- Lowered
- Increased
Protein and the bodybuilder:
True or False:
Competitive levels of body fat are generally unhealthy and impossible to maintain for prolonged periods of time
- True
After heavy resistance training, how can a client inhibit muscle-protein breakdown, resulting in a positive protein balance?
- Carbohydrate (1 g/kg or 0.5 gram per pound), not protein, consumed within an hour after heavy resistance training inhibits muscle-protein breakdown, resulting in a positive protein balance
Skeletal muscle is approx.
__% water
__% protein
_% fat, glycogen and other minerals
Skeletal muscle is approx.
- 72% water
- 22% protein
- 6% fat, glycogen and other minerals
1 pound of muscle tissue contains approximately ___ grams of protein
- 100 grams of protein
How much protein is required to build muscle?
- Additional 200-400 calories daily
(3-5 calories per kg or 1.5-2.5 calories per pound per day) above maintenance requirements - In addition to consuming a little extra protein (2 ounces of lean meat)
What is satiety?
- The feeling of fullness
How many grams of protein is recommended per kg of body weight per day for sedentary adults?
- 0.8 (0.4 g/lb)
How many grams of protein is recommended per kg of body weight per day for strength athletes?
- 1.2-1.7 (0.5-0.8 g/lb)
How many grams of protein is recommended per kg of body weight per day for endurance athletes?
- 1.2-1.4 (0.5-0.6 g/lb)
What is the Recommended Dietary Allowance (RDA) for protein in grams? In percentage of caloric intake?
- 0.8 g/kg/day
- 10 to 35% of total caloric intake
What are the negative side effects associated with chronic use of high-protein diets?
- Associated with higher intake of saturated fat and low fiber intake (risk factors for heart disease and some types of cancer)
- Kidneys are required to work harder to eliminate increase urea produced
- Requires 7x the water for metabolism than carbohydrate or fat
List some vegetarian complete protein foods sources.
- Milk and milk products
- Rice and beans
- Peanut butter on whole-wheat bread
- Sunflower seeds and peanuts
- Yogurt and granola
- Oatmeal with milk
- Lentils and bread
- Tortillas with beans or bean burritos
- Macaroni and cheese
- Hummus (chickpeas and sesame paste) with bread
- Bean soup with whole-grain crackers
List some vegan complete protein foods sources.
- Rice and beans
- Peanut butter on whole-wheat bread
- Sunflower seeds and peanuts
- Lentils and bread
- Tortillas with beans or bean burritos
- Hummus (chickpeas and sesame paste) with bread
- Bean soup with whole-grain crackers
List some animal based complete protein foods sources.
- Whole egg
- Meat, poultry, fish
- Milk and milk products
What are carbohydrates?
- Neutral compounds containing carbon, hydrogen, and oxygen and are generally classified as sugars (simple), starches (complex), and fiber (celluloses) which make up a large portion of animal foods
How is sugar written on a food label?
- Any monosaccharide or disaccharide
What are monosaccharides?
- Single sugar unit, many of which are connected to make starches (the storage form of carbs in plants) and glycogen (the storage form of carbohydrates in humans)
List three types of monosaccharides.
- Glucose (blood sugar)
- Fructose (fruit sugar)
- Galactose