Exam 1 Flashcards
What is the definition of nutrition?
the science of food; the nutrients and the substances therein, their action, interaction, and balance in relation to health and disease, the proccess by which the organism ingests, digests, absorbs, transports, utilizes, and excretes food substances
- a field that that draws on the biological sciences, chemistry, physiology and other sciences
Composition of Carbohydrates
Composed of carbon, hydrogen and oxygen
How many calories are provided by carbohydrates?
4 calories per gram (4 kcal/g)
Main function of carbohydrates in the body
used as energy/fuel for the body!
- simple
- complex
- Fiber is also a complex carbohydrate , but it is undigested since we lack the digestive enzymes to break it down
Composition of Lipids
- Refers to fats, oils and cholesterol
- Composed of carbon, hydrogen, oxygen
- Made up of 3 fatty acids attached to a glycerol molecule
How many calories are provided by lipids?
•9 calories per gram (9 kcal/gm)
Main function of lipids in the body
•Major form of fat in food, key energy source, and major form of energy stored in the body
Two types of Lipids: Saturated and Unsaturated
- Saturated fats are solid at room temp (ex: butter)
- Unsaturated fats are liquid at room temp (ex: olive oil)
- Linoleic acid and alpha-linolenic acid are 2 unsaturated fatty acids that are essential nutrients and must be supplied by our diet
Trans fatty acids
•unsaturated fats harmful for health,
they are found in deep fried foods, shortening and
baked goods
Trans fat
•liquid oil is made solid through a process called hydrogenation
Composition of Protein
- Composed of carbon, hydrogen, oxygen, and nitrogen
- Formed by bonding together amino acids
Calories provided by protein
•4 calories per gram
(4 kcal/g)
Function of protein in the body
- The main structural part of the body
- Components in blood, cell membranes, enzymes, immune factors, muscle and bone
- Provide energy for the body
How are carbohydrates classified?
Examples of simple carbohydrates
table sugar
- monosaccharides: glucose, fructose, galactose
- disaccharides: sucrose, maltose, lactose
Examples of complex carbohydrates:
starches, fibers
(potatoes/bread/etc)
GLUCOSE!!!!
glucose, fructose, and galactose are…
monosaccharides
sucrose, maltose, and lactose are…
disaccharides
What is the definition of a micronutrient?
- These are nutrients that are needed in small amounts in the diet, but do not provide energy
- Vitamins and minerals are considered micronutrients
What is the definition of a calorie?
- A term used to express the amount of energy in food
- Defined as the amount of heat energy to raise the
temperature of 1 gram of water 1 degree Celsius
Be able to calculate the amount of calories in food by applying physiological fuel values
- Carbohydrates →4 kcal per gram
- Protein → 4 kcal per gram
- Fat → 9 kcal per gram
- Alcohol → 7 kcal per gram (NOT an essential nutrient)
How do we assess nutritional status?
- Anthropometrics-Involves measuring several aspects of the body (i.e. height, weight, skinfold thickness, body circumference)
- Biochemical-Involves measurement of nutrients and nutrient byproducts in the blood, urine and feces
- Clinical-Search for physical signs of a diet-related disease (i.e. high blood pressure or a skin condition)
- Dietary-Measures food intake using a food frequency questionnaire (FFQ) or a 24-hour recall
- Environmental-Background data on a person such as education , level of income, housing information, etc
Limitations of Nutritional Assessment
- Signs and symptoms of nutritional deficiencies are not very specific, they may be caused by poor nutrition or something unrelated
- Signs and symptoms of nutritional deficiencies take a long time to develop, difficult to link an individual’s current diet and nutritional status
- A long time may lapse between initial development of poor nutritional health and first clinical evidence of a problem
Understand the steps in the Scientific Method
- Observe
- Hypothesize
- Conduct Experiment
- Evaluate Findings
- Experiment again
- Accept or Reject Hypothesis
Examples of experiment types used in Nutrition Research
- Laboratory animal experiment
- Human experiments (many types)
- Double-blind study
- Prospective cohort
- Case-control study
What is DSHEA?
•In 1994, the Dietary Supplement Health and Education (DSHEA) was passed, DSHEA defines and regulates dietary supplements
Where do I go to get nutrition-related advice?
- See a Registered Dietitian (RD)
- RDs are considered food and nutrition experts
- Visit the Academy of Nutrition and Dietetics (AND)homepage to find an RD near you
DRIs
- Dietary Reference Intakes
- DRIs are designed for planning and assessing diets of healthy people.
- Amounts recommended by DRIs are meant to promote good health and reduce incidence of chronic disease.
- The DRIs are not necessarily to be consumed every day, but should be consumed on most days, as an average intake
RDAs
- Recommended Dietary Allowances
- The original dietary standards
- The DRIs are energy and nutrient recommendations that have replaced the RDAs
4 sets of values for DRIs for macro- and micronutrients :
- (EAR) Estimated Average Requirement
- (AI) Adequate Intakes
- (RDAs) Recommended Dietary Allowances
- (ULs) Tolerable Upper Intake Levels
What are each of the values used for?
(EAR) Estimated Average Requirement
(AI) Adequate Intakes
(RDAs) Recommended Dietary Allowances
(ULs) Tolerable Upper Intake Levels
- Estimated Average Requirement (EAR) is used to evaluate nutrient intakes of populations.
- Adequate Intakes (AI) recommend specific amounts of nutrients for individuals.
- Recommended Dietary Allowances (RDAs) also recommend specific amounts of nutrients for individuals.
- 1.Tolerable Upper Intake Levels (ULs) help with the prevention of nutrient toxicities.
What are the two types of Energy Reccomendation DRIs and what are they for?
- (EERs) Estimated Energy Requirements: can be used to calculate calories needed to ensure a stable weight in a healthy individual.
- (AMDRs) Acceptable Macronutrient Distribution Ranges: are expressed as ranges, or proportions, of nutrients for healthy intake.
What is the AMDR for carbohydrates, protein, and fat?
- Carbohydrates: 45-65% of calories
- Fat: 20-35% of calories
- Protein: 10-35% of calories
What are daily values?
- A set of standards used on the Nutrition Facts panel to compare the amount of nutrients in food
- DVs were developed by the FDA
- DVs have been set for infants, toddlers, pregnant or lactating women and people over the age of 4
- DVs are based on:
- Reference daily intakes (RDIs) and
- Daily reference values (DRVs)
How do we interpret daily values on the nutrition facts labels?
- One serving or (6 meatballs) provides 11% of the DV for fat.
- You have used 11% of you fat allowance for the day by eating these meatballs.
- You still have 89% of your fat allowance left for the day.
What information is included on the nutrition facts panel?
(FnINSMiA)
- Serving size and servings per container-Based on typical American serving sizes
- Daily Value
- Nutrients -Total calories, calories from fat, total fat, saturated fat, cholesterol, sodium, total carbohydrates, fiber, sugars, protein, Vitamin A and C, calcium and iron
- Fortified or nutrients mentioned in health claims must also be included
- Ingredients
- Manufacturer information
- Allergens (Top 8-These include: Milk, eggs, fish, shellfish, peanuts, tree nuts, wheat and soy)
What are the top 8 allergens?
(ShMFSPEWTn)
Milk
eggs
fish
shellfish
peanuts
tree nuts
wheat
soy
4 types of claims on food labels and their definitions
- Nutrient Content Claims: Describes nutrients in a food (Ex: “Low in Fat” or “Rich in Vitamin A”)
- Structure/Function Claims: Describe how a nutrient affects human body structure or function (Ex: “Calcium help build strong bones”)
- Health Claims: Describes a relationship between a disease and nutrient or food (Ex: Oatmeal helps reduce cholesterol)
- Qualified Health Claims: hard to get, only limited evidence exists to support this type of claim
Nutrient density
- a way to assess the nutritional quality of food
- A food is said to be nutrient dense if it provides a greater contribution to your nutrient need than your calorie need
- more nutrients than calories ⇒ spinach
Energy density
- determined by comparing a food’s calorie content per gram weight of the food
- Energy-dense foods are high in calories, but weigh very little
- High energy -dense foods
- Graham crackers, potato chips, peanuts, bacon
What are the Dietary Guidelines for America and how often are they updated?
- The Dietary Guidelines for Americans are a set of diet and lifestyle recommendations designed to promote health and reduce chronic disease risks.
- recommendations are updated and published every 5 years
golf ball serving size
2 tbsp
tennis ball serving size
1/2 to 2/3 of a cup
deck of cards serving size
1/2 to 3/4 of a cup; 3 oz of meat
baseball serving size
1 cup
What are the main food categories on MyPlate?
- fruits
- vegetables
- grains
- dairy
- meat
What are the 4 main types of tissues and how do they differ from each other?
- Epithelial: Cells that cover surfaces inside and outside of the body (absorb, secrete, excrete and protect)
- Connective: Support and protect the body by holding structures together, stores fat, and produces blood cells (tendons, bones, arteries, veins)
- Muscle: Contract and relax to permit movement
- Nervous: Transmit nerve impulses
What are the main organs of the human digestive system?
What organs are considered accessory organs?
Main organs:
Mouth, esophagus, stomach, small intestine, large intestine
Accessory organs:
Liver, pancreas and gall bladder
Digestive Disorders
- Heartburn and Gastroesphogeal reflux disease (GERD)
- (Peptic) Ulcers
- Food Intolerances
- Intestinal Gas (Flatulence)
- Constipation
- Diarrhea
- Irritable Bowel Syndrome (IBS)
- Hemorrhoids
- Inflammatory Bowel Disease (IBD)
- Gallstones
What types of food are allowed on a gluten free diet?
- Corn, rice, quinoa, and buckwheat OK
Where does most nutrient absorption occur?
Most digestion and absorption occurs in the
small intestine
Function of sphincters
Ring like muscles that control the flow of contents in the GI tract
- Lower esophageal sphincter (cardiac)
- Pyloric sphincter
- Sphincter of Oddi
- Ileocecal sphincter
- Anal sphincter
Function of Mouth
- Chewing increases surface area
- Mixed with saliva food becomes a bolus
- Saliva
- Lysozyme
- Breaks down bacteria
- Mucus
- Lubricates and hold bolus together
- Amylase
- Breaks down starch
- Enhances perception of flavor
Function of the Esophogus
- Swallowing
* Moves bolus from the mouth to the esophagus - Epiglottis
- Prevents food from entering the trachea
- Closes over the larynx
Function of the Stomach
- Food bolus enters stomach through lower esophageal sphincter
- Holding & mixing tank
- Mixed with stomach secretions food becomes chyme
Function of the Small Intestine
- Most digestion and absorption occurs here
- Pyloric sphincter allows chyme into the small intestine
- Gastric inhibitory peptide (hormone) slows release of chyme
1. Three main sections: - Duodenum, jejunum and ileum
Function of the Liver
- Provides bile
- Enterohepatic circulation (recycling of bile)
Function of the Gallbladder
- Bile storage
Function of the Pancreas
- Produces sodium bicarbonate, lipases, proteases and pancreatic amylase
Functions of the Large Intestine
- Absorption of water and electrolytes
- Formation and expulsion of feces
- Housing of bacteria (microbiota)
What role does Gastrin play in digestion and absorption?
a hormone that controls release of HCl and pepsinogen in the stomach
What role does CCK play in digestion and absorption?
- Hormone: Cholescystokinin
- Release of bile
What role does HCl (Hydrochloric Acid) play in digestion and absorption?
- Inactivates proteins
- Destroys bacteria and viruses
- Dissolves minerals to aid in absorption
- Converts pepsinogen into pepsin
Whate role does bicarbonate play in digestion and absorption?
sodium bicarbonate is produced by the pancreas, and released by the hormone secretin.
- When ingested, for example, with mineral water, it helps buffer lactic acid generated during exercise and also reduces the acidity of dietary components.
- neutralize
What is the definition of satiety?
The sense of fullness between eating episodes that can inhibit further eating
How do we achieve satiety…it is complex!
- Sensory aspects of food
- Chewing
- Stomach expansion after we eat
- Digestion, absorption, metabolism, hormone production (GLP-1, peptide YY, ghrelin)
Negative Energy Balance vs. Positive Energy Balance
- Positive energy balance: When energy intake exceeds the energy expended WEIGHT GAIN
- Negative energy balance: When energy intake is less than energy expenditure WEIGHT LOSS
What factors increase basal metabolism?
- Greater muscle mass*
- Larger body surface area
- Gender (males)
- Body temperature
- Higher secretion of thyroid hormone
- Nervous system
- Growth
- Caffeine and tobacco use
- Recent exercise
What factors decrease basal metabolism?
- Lower than normal secretions of thyroid hormones
- Restricted calorie intake
- Less body surface area and muscle mass
- Aging: ≥30 years
What are the different ways that we measure energy expenditure?
The amount of energy a body uses can be measured in 3 ways:
- Direct calorimetry: estimates energy expenditure by measuring the amount of body heat released by a person
- Indirect calorimetry: the most COMMON method used, it involves collecting expired air from an individual during a specified amount of time. This procedure can be done in a laboratory or with a handheld device.
- Estimated energy requirements (EERs): measurements based on formulas developed by the Food and Nutrition Board, that can estimate energy needs using a person’s weight, height, gender, age and physical activity level.
What are the different methods for measuring body fat?
Body fat can be measured in five different ways:
- Underwater weighing ”The Gold Standard”
- Air displacement
- Skinfold thickness
- Bioelectrical impedance
- Dual energy X-ray absorptiometry (DEXA)-(considered the most accurate way to measure body fat, but expensive!)
Apple and Pear Body Fat Distribution
Apple: Upper body fat distribution (Android; apple shape)
Pear: Lower body fat distribution (Gynoid: pear shape)
- Men: waist circumference > than 40 inches indicates upper body obesity
- Women: waist circumference > than 35 inches indicates upper body obesity
Definition and Physical Effects/Criteria of Anorexia Nervosa
Definition: Involves a psychological loss or denial of appetite followed by self-starvation.
Symptoms:
- Low body weight
- Low body temperature
- Slower metabolic rate
- Iron deficiency, anemia
Definition and Physical Effects/Criteria of Bulimia Nervosa
Definition: Disorder in which large quantities of food are eaten at one time and counteracted by purging food from the body, fasting, and/or excessive exercise
Physical Effects/Criteria:
- Demineralization of teeth due to acid
- Low blood potassium
- Stomach ulcers
- Constipation
- Death
Definition and Physical Effects/Criteria of Eating Disorders Not Otherwise Specified (EDNOS)
Definition: A broad category of eating disorders in which individuals have partial syndromes that do not meet the criteria for anorexia or bulimia
Physical Effects/Criteria:
- Recurrent binge-eating episodes
- Feelings of distress regarding binge eating
- Eating more rapidly than usual, eating until uncomfortably full
Definition and Physical Effects/Criteria of Binge-Eating Disorder
Definition: Part of EDNOS, this disorder will be recognized as a separate diagnosable disease when the next Diagnostic and Statistical Manual of Mental Disorders is published.
Physical Effects/Criteria:
- Recurrent binge-eating episodes
- Feelings of distress regarding binge eating
- Eating more rapidly than usual, eating until uncomfortably full
How to calculate body mass index (BMI)
Body weight (in kg)/Height2 (in meters)
How is BMI classified?
- Underweight BMI: <18.5 kg/m2
- Healthy BMI Range: 18.5-24.9 kg/m2
- Overweight BMI: 25-29.9 kg/m2
- Obese BMI: ≥ 30 kg/m2
