The Role of Nutrition
in Our Health
Chapter 1
Test Yourself1. A calorie is a measure of the amount of fat in
a food.
2. Proteins are not a primary source of energy for our bodies.
3. All vitamins must be consumed daily to support optimal health.
4. The Recommended Dietary Allowance is the maximum amount of a nutrient that people should consume to support normal body functions.
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What is Nutrition?
Nutrition is a relatively new discipline of science.
Nutrition: the study of food, includingHow food nourishes our bodiesHow food influences our health
Digestion Absorption Utilization Excretion
How Does Nutrition Contribute to Health?
Nutrition contributes to wellness.
Wellness: more than absence of disease
Many factors contribute to an individual’s wellness. Primary among these are:
Nutrition Physical activity
How Does Nutrition Contribute to Health?
Healthful diet is part of disease prevention
How Does Nutrition Contribute to Health?
How Does Nutrition Contribute to Health?
Nutrition is so important it has become a national goal to promote optimal health and disease prevention.
Goals of Healthy People 2020 – this is a health promotion and disease prevention plan for the United States.
1. Increase quality and years of healthy life
2. Eliminate health disparities
How Does Nutrition Contribute to Health?
Obesity is a growing problem in the U.S.
Note the states in dark “red” which indicates a prevalence of obesity >30%
What Are Nutrients?
Nutrients: chemicals in foods that our bodies use for energy and to support the growth, maintenance, and repair of our tissues. Six groups of nutrients:
1. Carbohydrates2. Lipids3. Proteins4. Vitamins5. Minerals6. Water
What Are Nutrients?
Essential nutrients: nutrients for which specific biological functions have been identified, and which our bodies cannot make enough of to meet our biological needs
♦ Essential nutrients must be obtained from our diet
♦ Examples: Vitamin C, Calcium, Thiamin
What Are Nutrients?
Macronutrients: nutrients required in relatively large amounts.
Carbohydrates, lipids, proteinsProvide energy to our bodies
Micronutrients: nutrients required in smaller amounts.
Vitamins and minerals
What Are Nutrients?
Organic nutrients: nutrients contain an element of carbon that is an essential component of all living organisms
Carbohydrates, lipids, proteins, vitamins
Inorganic nutrients: nutrients that do not contain carbon
Minerals and water
Energy From Nutrients
We measure energy in kilocalories (kcal).
Kilocalorie: amount of energy required to raise the temperature of 1 kg of water by 1oC.
On food labels, “calorie” actually refers to kilocalories.
Carbohydrates
•Primary source of fuel for the body, especially for the brain and physical activity.
•Provide 4 kcal per gram.
Carbohydrates are found in grains (wheat, rice), vegetables, fruits, and legumes (lentils, beans, peas), milk products.
Lipids - triglycerides, phospholipids, sterols
•Insoluble in water.
•Provide 9 kcal per gram.
•An important energy source during rest or low intensity exercise.
•Stored as adipose tissue (body fat) – major form of stored energy.
•Foods containing lipids also provide fat-soluble vitamins and essential fatty acids.
Proteins
•Proteins are chains of amino acids.
•Support tissue growth, repair, and maintenance.
•Proteins can supply 4 kcal of energy per gram, but are not a primary energy source.
•Proteins are an important source of nitrogen.
Vitamins
Vitamins are organic molecules that assist in regulating body processes: critical in building and maintaining healthy
bones and tissues support immune system ensure healthy vision Many can be destroyed by heat and oxidation
Vitamins do not supply energy to our bodies; however, many vitamins act as coenzymes for energy producing reactions
Vitamins
Type Names Distinguishing Features
Fat Soluble A,D,E, and K •Soluble in fat•Stored in the human body•Toxicity can occur from consuming excess amounts, which accumulate in the body
Water Soluble C, B-vitamins (thiamin, riboflavin, niacin, vitamin B6, vitamin B12, pantothenic acid, and folate)
•Soluble in water•Not stored to any extent in the human body•Excess excreted in urine•Toxicity generally occurs as a result of vitamin supplmentation
Minerals
Minerals are inorganic substances required for body processes.
Minerals have physiological functions, such as fluid regulation, energy production, bone structure, muscle movement, and nerve functioning.
Minerals
Our bodies require at least 100 mg per day of the major minerals such as:
•Calcium
•Phosphorus
•Magnesium
•Sodium
•Potassium
•Chloride.
We require less than 100 mg per day of the trace minerals such as:
•Iron
•Zinc
•Copper
•Selenium
•Iodine
•Fluoride
Water
Inorganic nutrient, essential for survivalInvolved in many body processes:
fluid balance and nutrient transportnerve impulsesbody temperatureremoval of wastesmuscle contractionschemical reactions
Determining Nutrient Needs
Dietary Reference Intakes (DRIs): updated nutritional standards
Expand on the traditional RDA valuesSet standards for nutrients that do not have
RDA valuesDietary standards for healthy people onlyFor preventing deficiency diseases and
reducing chronic diseases
Determining Nutrient Needs
Determining Nutrient Needs
Estimated Average Requirement (EAR)
The average daily intake level of a nutrient that will meet the needs of half of the healthy people in a particular category
Used to determine the Recommended Dietary Allowance (RDA) of a nutrient
Determining Nutrient Needs
Recommended Dietary Allowances (RDA)
The average daily intake level required to meet the needs of 97 – 98% of healthy people in a particular category
Determining Nutrient Needs
Adequate Intake (AI)Recommended average daily intake level for a
nutrientBased on observations and experimentally
determined estimates of nutrient intakes by healthy people
Used when the RDA is not yet established: calcium, vitamin D, vitamin K, fluoride
Determining Nutrient Needs
Tolerable Upper Intake Level (UL)Highest average daily intake level likely to pose
no risk of adverse health effects to most peopleConsumption of a nutrient at levels above the
UL, the potential for toxic effects and health risks increases
Determining Nutrient Needs
Example Nutrient DRI
Vitamin C (adult age 19-70)
UL = 2,000 mg/d
RDA = 75 mg/d (female)
90 mg/d (male)
EAR = 60 mg/d (female)
75 mg/d (male)
Amount needed to prevent
Deficiency = ~10 mg/d
Determining Nutrient Needs
Estimated Energy Requirement (EER)Average dietary energy intake (kcal) to
maintain energy balance in a healthy adultBased on age, gender, weight, height, level of
physical activity
Determining Nutrient Needs
Acceptable Macronutrient Distribution Ranges (AMDR)
Describes the portion of the energy intake that should come from each macronutrientCarbohydrates: 45-65%Fats: 20-35%Proteins: 10-35%
Potential for inadequate nutrient levels if nutrient intake falls below this range
Potential for increased chronic disease risk if nutrient intake falls above this range
AMDR
Malnutrition
Nutritional status is out of balance: Individual is getting too much or too little of a particular nutrient or energy over a significant period of time
Undernutrition: too little energy or too few nutrients, causing weight loss or a nutrient deficiency disease
Overnutrition: too much energy or too much of a given nutrient over time, causing obesity, heart disease, or nutrient toxicity
Assessing Nutritional Status – A,B,C,D’s
A – Anthropometric Data♦ Weight, Height, Muscle Mass, Fat Mass
B – Biochemical Data♦ Cholesterol, Glucose, Albumin, Sodium, Liver
Enzymes, Kidney Enzymes
C- Clinical Data♦ Disease history, Socioeconomic Status, Physical Exam
D – Dietary Data♦ Nutrient intake, supplement use
Dietary Intake Tools
Dietary Intake Tools
24-Hour Recall Diet HistoryFood Frequency Questionnaire
Diet Records
Twenty-four Hour Recall
Recalls all food and beverages consumed in the previous 24-hour period
Accurate recall includes serving sizes, food preparation methods, and brand names of convenience foods or fast foods
Limitations: may not be typical intake rely on memory ability to estimate portion sizes
Diet History
Information from interview or questionnaire: Weight (current and usual weight, goals) Factors affecting appetite and food intake Typical eating pattern (time, place, dietary restrictions,
frequency of eating out, etc.) Disordered eating behaviors (if any) Education and economic status Living, cooking/food purchasing arrangements Medication and dietary supplements Physical activity
Food Frequency Questionnaires
Determine typical dietary pattern over a predefined period of time
Include lists of foods with the number of times these foods are eaten
Some assess only qualitative information (typical foods without amounts)
Semiquantitative questionnaires assess specific foods and quantity consumed
Diet Records
List of all foods and beverages consumed over a specific time period (3-7 days)
Kept by person seeking nutritional advice
More accurate with: foods are weighted or measured labels of convenience foods and supplements
People may change food intake to simplify record keeping
Analyses are time consuming and costly
Nutrition Deficiencies
Primary deficiency occurs when a person does not consume enough of a nutrient, a direct consequence of inadequate intake
Secondary deficiency occurs when…a person cannot absorb enough of a nutrient in
his or her bodytoo much nutrient is excreted from the bodya nutrient is not utilized efficiently by the body
Primary or Secondary Deficiency?
Jane is a strict vegetarian and does not consume any animal-based foods and does not consume a vitamin/mineral supplements.
John consumes a regular diet consisting of all major food groups but has a condition called “gastritis” preventing his production of intrinsic factor, which is needed to help absorb vitamin B12
Jane and John were both told by their primary care physicians that they had a type of anemia called “pernicious anemia” which is caused by a deficiency of vitamin B12 in the body. What type of deficiency do Jane and John have based on the evidence below?
Deficiency Symptoms
Subclinical deficiency occurs in the early stages, few or no symptoms are observed
Covert symptoms are hidden and require laboratory tests or other invasive procedures to detect
Symptoms of nutrition deficiency that become obvious are referred to as overt
Nutrition DeficienciesWhat happens in the body:
Physical deficiency caused by inadequate diet OR secondary deficiency caused by problem inside the body
Declining nutrient stores
Abnormal functions inside the body
Physical (outward) signs and symptoms
Which assessment method reveals changes:
Diet historyHealth history
Laboratory tests
Laboratory test
Physical examination and anthropometric measures
Registered Dietitians (RD)
Requirements: Bachelor’s degree in nutrition Completion of supervised clinical experience Passing a national registration examination
Work in a variety of settings: Hospitals, clinics, nursing homes Sports nutrition Food-service management Community and public health nutrition Nutrition research
Nutrition Advice: Who Can You Trust?
Nutrition is a new science
Increased interest in nutrition
Overwhelming amount of health claims
Reliability of nutrition information
Misinformation
Potential harmful quackery
Trustworthy Nutrition Experts
Registered Dietitian (RD)
Licensed Dietitian meets the credentialing requirements of a given state
Nutritionist has no legal definition
Professional with advanced nutrition degree (masters-MS, MA; doctoral-PhD)
Physician
Government Information Sources
Centers for Disease Control and Prevention (CDC)
National Health and Nutrition Examination Survey (NHANES)
Behavioral Risk Factor-Surveillance System (BRFSS)
National Institutes of Health (NIH)
Reliable Nutrition Information
American Dietetic Association
American Society for Nutrition Sciences
American Society for Clinical Nutrition
Society for Nutrition Education
American College of Sports Medicine
North American Association for the Study of Obesity
Evaluating Research
• Case Control Studies
• Clinical Trials• Randomized• Single Blind• Double Blind• Placebo
Evaluating Media Reports
• Questions to ask?• Who conducted/paid for the research?• Who is reporting the information?• Is it based on reputable research studies?• Is the report based on testimonials?• Are the claims too good to be true?• Is someone profiting?
Activity
Calculate the Nutrition
Fat = 18 grams
Carbs = 6 grams
Protein = 7 grams
Total Calories: _________
____% Fat _____ % Carbs ______% Protein
Calculate the Nutrition
Fat = 18 grams
Carbs = 6 grams
Protein = 7 grams
Total Calories: 214
76% Fat
11% Carbs
13% Protein
Calculate the Nutrition
Fat = 8.4 grams
Carbs = 23.4 grams
Protein = 4.2 grams
Fat = 2 grams
Carbs = 0 grams
Protein = 28 grams
Calculate the combined calories, protein, fat, carbs and the percentage.
Calculate the Nutrition
Fat = 10.4 grams (93.6 calories)
Carbs = 23.4 grams (93.6 calories)
Protein = 32.2 grams (128.8 calories)
Total Calories: 316
~30% Fat
~30% Carbs
~40% Protein
Calculate the Nutrition
Total Calories: 680
Fat: ______
Carbs: 71 grams
Protein: 44 grams
Calculate the Nutrition
Total Calories: 680
Fat: 24 grams
Carbs: 71 grams
Protein: 44 grams
Calculate the Nutrition
The doctor has recommended his patient eat a 1600 calorie diet that is 50% carbs, 25% protein and 25% fat.
How many grams and calories will the patient be eating from each of the three macronutrients?
Calculate the Nutrition
Answer:
Calories: 1600
Carbs: 200 grams (800 calories)
Protein: 100 grams (400 calories)
Fat: 44 grams (400 calories)
Evaluating Research
Health Benefits of Chocolate
A Look at Goji Juice – Scam or Super Fruit
High Fructose Corn Syrup