Food and Nutrition

• Building blocks of protein
• Proteins are sequences of this

• Essential- must be obtained from diet
• Nonessential- can be made in body

• 20 different Amino Acids
• 9 are essential

• Chain of Amino Acids
• - Sequence of Amino Acids determines shape
• - Shape determines function

• Irreversible change in a protein’s shape
• - Brought about by heat, acid or other agents
• - Disrupts function
• - Examples:
• Hardening of an egg due to cooking
• Curdling of milk when heating

• Requires that all essential Amino Acids available
• Controlled by DNA
• DNA is a template for synthesis of mRNA
• The sequence of Amino Acids is determined from a subunit
• of DNA= gene
• Sequence of amino acids determines the shape and
• function

• May alter proteins functions
• Example: Sickle Cell Anemia

• Structural and Mechanical Functions
• Enzymes
• Hormones
• Immune Function
• Fluid Balance
• Acid-Bace Balance
• Transport
• Source of Energy
• Nitrogen Balance

• Collagen
• Motor Protein

Antibodies attack viruses and bacteria

Acts as buffers

Lipoproteins, other carrier molecules

4 kcals in grams

• Used for Protein
• Positive Nitrogen Balance
• Negative Nitrogen Balance
• Zero Nitrogen Balance

• N intake > N output
• - Body retains N
• - Examples:
• Pregnancy
• Growth
• Muscle building

• N intake < N output
• - Body loses N
• - Examples:
• Weight loss diet
• Illness
• “Wasting Disease”

• N intake = N output
• - Equilibrium

EAA= Essential Amino Acid

• Supplies all essential Amino Acids
• - Animal proteins, soy protein

• Low in 1 or more essential AA
• - Most plant proteins

• Take 2 incomplete proteins to make complete protein
• - Must eat within the same day
• Legumes
• Grains

• Adults: 0.8 g/kg x Body Weight in kg
• - Example:
• 220 lbs/2.2= 100 kg
• 100 x 0.8= 80 g protein
• - If vegetarian, need 1.8 g/kg x Body Weight in kg

Need adequate energy (carb) in diet, to “spare protein” so protein is not used for energy

• Excess protein
• - It generates too much ammonia (NH3) to be excreted by kidneys

A single Amino Acid can inhibit absorption of other Amino Acids (get Amino Acid deficiency)

NO SUPPLENTENTS REQUIRED: IF TOO MUCH EXTRA PROTEIN= EXTRA CALORIES= EXTRA FAT

• A deficiency of both protein and energy
• The most widespread form of malnutrition in the world

• Are low in plant foods (fiber, vitamins, phytochemicals)
• - Increase risk for heart disease
• - Linked with colon cancer
• - Are a burden on the kidney
• Recommendation: no more than 2x RDA for protein

• Avoids: meat, fish and poultry
• Eats: eggs and dairy
• Most common type in US and Canada

• “Strict vegetarian”
• Avoids all animal products (meat, eggs, dairy, fish, even honey)

• Historically, most people of the world have eaten a largely vegetarian diet
• Only in affluent societies (Europe and North America) has a diet centered around meat

• Low in cholesterol, saturated fat
• - Cholesterol is only from meat, eggs, dairy, fish
• High in fiber
• - Whole grains, fruit, vegetables
• Contains healthy fats
• - Nuts, seeds, avocados
• Thus: Less Chronic Disease
• - Heart disease, cancer, diabetes, obesity

• Health
• Concern for the Environment
• Political Issues
• Ethical Choice
• Aesthetic Reasons

• Primary reason to switch to vegetarianism
• - Decreased incidence of chronic disease..

• Cattle grazing à erosion of topsoil
• Pollution and large resource use from large animal farms
• More protein per acre from plants than animals

• Compassion for animals, Religious reasons
• - Example:
• Hinduism, or Seventh Day Adventist

Don’t like taste or look of meat

• Example:
• - To help alleviate world hunger; can grow more plant protein

• Vegetable sources of protein are incomplete
• Must “complement” plant proteins
• To receive all necessary amino acids, must be eaten within the same day
• - Grains and legumes
• - Grains and milk products
• - Legumes and seeds

• Protein
• Calcium
• Iron
• Zinc
• Vitamin D
• Vitamin B12

• Vitamin D
• - IF don’t eat dairy or don’t get 20 minutes/ week
• of summer sun
• Vitamin B12
• - If don’t eat animal products or B12-fortified foods

• Travel freely in the blood
• Excess excreted, typically not stored in body
• Risk for toxicity low, must consume RDA frequently
• Main role in metabolism
• Kidney detect and secrete excess thru urine
• Needed in frequent doses (1-3 days)

• Functions:
• - Coenzyme of energy metabolism
• - Nerve membrane integrity
• Dietary Source:
• - Pork
• - Whole grains
• - Enriched grains
• - Legumes
• Deficiency Symptoms:
• - Beriberi
• - Muscle weakness
• - Wasting of lower extremities
• - Heart failure
• - Edema
• Toxicity Symptoms:
• - None

• Major Functions:
• - Coenzyme of energy metabolism
• Dietary Source:
• - Milk/Milk Products
• - Enriched grains
• - Meat
• Deficiency Symptoms:
• - Cracks at corners of mouth
• - Sensitivity to light
• - Skin rash
• Toxicity Symptoms:
• - None

• Major Functions:
• - Coenzyme of energy metabolism
• Dietary Source:
• - Protein foods
• - Enriched grains
• - Made from tryptophan (amino acid)
• Deficiency Symptoms:
• - Pellagra
• - Diarrhea
• - Dementia
• - Dermatitis
• - Death
• Toxicity Symptoms:
• - Skin flushing
• - Blurred vision
• - Liver damage

• Major Functions:
• - Coenzyme involved inDNA synthesis
• - Requires B12 to function
• Dietary Source:
• - Enriched grains
• - Green vegetables
• - Legumes
• Deficiency Symptoms:
• - Impaired cell division
• - Megaloblastic anemia
• - Neural tube defects (infants)
• Toxicity Symptoms:
• - Masks B12 deficiency symptoms

• Major Functions:
• - Coenzyme of folate metabolism
• - Maintains sheath around the nerves
• - New cell synthesis
• Dietary Source:
• - Only animal based foods
• - Fortified breakfast cereals
• Deficiency Symptoms:
• - If no intrinsic factor, then Pernicious anemia
• - If low intake, then Megaloblastic anemia
• - Poor nerve function
• Toxicity Symptoms:
• - None

• Major Functions:
• - Amino acid metabolism
• - Fat metabolism
• - Makes hemoglobin for red blood cells
• - Neurotransmitter synthesis
• Dietary Source:
• - Meat
• - Potatoes
• - Bananas
• Deficiency Symptoms:
• - Rashes, scaly skin
• - Depression/confusion
• - Anemia
• Toxicity Symptoms:
• - Nerve damage

• Major Functions:
• - Coenzyme of carbohydrates, fat, and protein metabolism
• Dietary Source:
• - Widespread in foods
• - Whole grains
• - Egg yolks
• Deficiency Symptoms:
• - Depression
• - Muscle Pain
• - Fatigue
• Toxicity Symptoms:
• - Unknown

• Major Functions:
• - Coenzyme of energy metabolism
• - Involved in synthesis of many compounds
• Dietary Source:
• - Widespread in foods
• - Meats
• - Whole grains
• Deficiency Symptoms:
• - Hypoglycemia
• Toxicity Symptoms:
• - None

• Major Functions:
• - Antioxidant
• - Collagen synthesis
• - Helps in iron absorption
• - Supports immune system
• Dietary Source:
• - Citrus fruits
• - Cabbage type vegetables
• - Dark green vegetables
• Deficiency Symptoms:
• - Scurvy
• - Poor wound healing
• - Bruising
• - Frequent infections
• Toxicity Symptoms:
• - Nausea
• - Diarrhea
• - Interferes with medications

• Trapped in cells associated with fat
• Many require a protein carrier for transport
• Require bile for absorption
• Likely to remain in the body for long periods of time (stored)
• Can eat less than RDA for periods of time if stores are high (need periodic doses)
• Likely to reach toxic levels when consumed in excess (supplements)

• Major Functions:
• - Promotes vision
• - Promote cell division
• - Reproduction
• - Antioxidant: Beta-Carotene
• -Supports immune system
• -Promotes growth
• Dietary Source:
• -Vitamin A:
• - Liver
• - Fortified milk
• - Cheese
• -Beta-Carotene
• - Spinach
• - Carrots
• - Sweet potatoes
• FAST FOODS ARE POOR SOURCE
• Deficiency Symptoms:
• - Night blindness
• - Xerophthalmia
• - Keratinization
• - Poor growth
• - Poor immunity
• Toxicity Symptoms:
• - Fetal malformations
• - Liver failure
• - Fractures
• - Seen in supplementation and too much liver

• Synthesized in the body by sunlight
• Is a hormone
• Major Functions:
• - Promotes blood calcium levels
• - Many target tissues for it
• Dietary Source:
• - Only animal-based foods
• - Fortified milk
• - Egg yolk
• - Liver
• - Fatty fish
• - Sun exposure
• Deficiency Symptoms:
• - Similar to calcium deficiency
• - Rickets in children
• - Osteomalacia in adults
• Toxicity Symptoms:
• - Calcium deposits in soft tissues
• - Kidney damage
• - Most likely vitamin to become toxic

• Major Functions:
• -Antioxidant
• - Protects Vitamin A and unsaturated fatty acids
• - May decrease risk of heart disease
• - Protect lungs from air pollution
• - Helps immune function
• Dietary Source:
• - Vegetable oils
• - Nuts and seeds
• - Whole grains
• Deficiency Symptoms:
• -Not common
• - Nerve degeneration
• - Breaking of RBC
• Toxicity Symptoms:
• -Not common
• - Hemorrhage (=bleeding)

• Major Functions:
• - Blood clotting
• - Synthesis of bone proteins
• Dietary Source:
• - GI bacteria
• - Leafy green vegetables
• - Cabbage
• - Milk
• Deficiency Symptoms:
• - Hemorrhaging
• - Skeletal weakness
• Toxicity Symptoms:
• -Not common
• - Reduced effectiveness of anti-clotting medications
• - Jaundice
• - Red blood cell breaking

• Caused by bacteria, viruses, parasites
• Transmitted from one person to another through contact via air, water, food, or vector organisms

• Irreversible
• Characterized by degeneration of body organs due to:
• § Genetic predisposition
• § Personal medical history
• § Poor lifestyle choices
• - Poor food choices, smoking, excessive alcohol use, lack of PA

• Low Protein
• Low Energy
• Low Vitamin A, E, and D
• Low B-vitamins, Folate, Vitamin C
• Low Copper, Magnesium, Selenium
• High and Low Iron
• High and Low Zinc

• Cancer
• HIV/AIDS
• § Result in wasting body tissue

• Results in 1 million deaths annually in the US
• #1 cause of death in developed nations
• Population at risk:
• - Men: more likely to experience MI
• - Women: more likely to die from MI

• Development:
• § Soft, fatty streaks along inner wall of artery
• § Streaks enlarge, becoming hard plaques
• - Contributes to inelastic, narrow vessel walls

• Abnormal blood clotting
• - Thrombus
• - Embolus

Stationary blood clot

• A thrombus that breaks loose
• - Results in heart attack or stroke

• "Atherogenic Diet”- influence plaque formation
• § High in saturate fat and trans fat
• § Low in vegetables, fruits, whole grains
• § Low in omega-3 fatty acids --> oppose clot formation

• High blood LDL cholesterol, low blood HDL cholesterol
• Hypertension
• Toxins from cigarette smoking
• Viral and bacterial infections
• Obesity
• Diabetes
• Physical inactivity

• Role of the kidneys during dehydration and Atherosclerosis
• - Constrict blood vessels --> increases Blood Pressure
• - Exacerbates Atherosclerosis
• = High blood pressure --> increased damage to arteries --> increased clot formation
• - Atherosclerosis exacerbates this
• = Hardened arteries and clots --> decreased blood flow to kidneys --> increased blood pressure -->
• hypertension

• Obesity (especially central adiposity)
• Atherosclerosis
• Insulin resistance/Type 2 Diabetes Mellitus

• Age: most develop hypertension in 50s and 60s
• Genetic predisposition to hypertension
• - African Americans have greater prevalence of hypertension
• § However, obesigenic US environment plays a role prevalence

• Systolic Pressure
• Diastolic Pressure
• Ideal resting blood pressure: 120/80
• Borderline normal blood pressure: 130/85

Pressure during contraction of heart

Pressure during relaxation of heart

• Increase fruits, vegetables, fish, and low-fat dairy product consumption
• Reduce sodium intake
• Reduce fat intake
• Adequate intake of calcium, potassium, magnesium, Vitamin C

Loss of as little as 10 lbs has a significant effect on hypertension

• Sodium plays a role in maintenance of body fluid homeostasis
• - Regulates extracellular fluid and plasma volume
• High sodium diet associated with hypertension
• - Increases blood pressure
• § Lowering sodium intake decreases BP regardless of gender or race

• Chronic disease characterized by elevation of blood glucose concentrations and inadequate or ineffective insulin, which impairs a person’s ability to regulate blood glucose normally
• The role of insulin
• Two types:
• - Type 1
• - Type 2

• Pancreas produces little or no insulin
• - Leading disease for children

Pancreas makes plenty of insulin, but body’s cells resist insulin’s action= insulin resistance- believed to be a consequence of obesity

• Adequate fiber
• Moderate added sugars
• Controlled total carbohydrate to regulate glucose intake
• Low saturated fat and adequate unsaturated oils
• Adequate but not very high protein intake

• Disease in which cells multiply faster than normal and disrupt normal functioning of organ(s)
• 2nd leading cause of death in US

• 1. Exposure to carcinogen
• 2. Carcinogen enters cell
• 3. Carcinogen damages or changes cell’s DNA= initiation
• 4. Damage promoted by other carcinogens, called promoters; cell begins to multiply out of control= tumor formation
• 5. Cancer cells spread via blood and lymph= metastasis
• 6. Disruption of normal body functions

• Carcinogens can be food substances
• Normally, the body detoxifies the small doses of carcinogens that occur naturally in foods
• As processing increases, see an increase in potential carcinogens via food additives
• 15% of cancer could be eliminated by preventing overweight and obesity
• Diets high in fruits and vegetables
• - Linked to low occurrence of cancer
• Diets high in dietary fat, meat, alcohol, excess calories
• - Linked to increased risk of cancer

• Whole grains, fruits, and vegetables high in antioxidants and phytochemicals:
• - Prevent initiation and progression of cancer
• - Cruciferous vegetables- associated with decreased risk of colon cancer
• - Phytochemicals are functional foods:
• § Promote health
• § Fight disease

• Not enough reserves
• Can’t fight wasting disease (Cancer)

• Increased chronic disease
• Central obesity (“apple shape”) is especially dangerous

• Ratio of weight to height
• - Healthy BMI= 18.5-24.9
• - Overweight= 25-29.9
• - Obese= 30

• Food and beverages consumed (=calories)
• Hunger
• Appetite

• Physiological (internal) drive to eat
• - Low blood glucose
• - Controlled by internal body

• Psychological (external) drive to eat
• - Often in the absence of hunger
• - Food “looks” good to eat

• Basal Metabolic Rate (BMR)
• Thermic Effect of Food (TEF)
• Physical Activity

• For metabolism, breathing, temperature maintenance etc. (involuntary activities) while at complete rest
• - 60-65% of calories needed
• - Greatest component of energy expenditure

• Energy needed to digest food; 10% of total energy needs
• - 5-10% of calories needed

• Intentional activity
• Examples:
• - Walking
• - Sitting
• - Running
• - Moving
• 25-35% of calories needed

• BMR x Thermic Effect x Activity Level
• 1 lb of body fat= 3500 calories

Skin fold test

Weight in water vs. weight in air

Fat has different electrical resistance than water

Fat responds differently to x-rays than water

• Estimates body volume by measuring air pressure
• Get body density from: Body Mass/Volume
• Then can estimate body fat from body density

• Adopted children have weight similar to biological parents not adoptive parents
• If one obese biological parent= 60% chance of obese child
• If two biological parents are obese- 90% chance of obese child

• Palatability of foods (especially fat content)
• Food availability
• Highly palatably, high calorie, affordable foods available 24/7 (big problems in U.S.)

Physical inactivity

Loneliness, addiction, depressions, stress

• Obesity is influenced by total # of fat cells in body
• Most fat cells are formed during childhood
• Can help limit fat potential if limit # fat cells in childhood (prevent childhood obesity)

• Body fat is maintained around a set point (like a thermostat)
• Obese people have a high set point