Nutrition Exam 3

All Macronutrients Can Contribute

Extra fat, carbs, or protein → stored as body fat

The body converts what it doesn't need into fat reserves

Alcohol Adds More Than Calories

energy is also stored as fat

What Happens in your body in energy imbalance?

Fat cells (adipocytes) enlarge as they store more fat

Leads to increased fat mass and weight gain

Subcutaneous Fat located?

beneath the skin

Function of Subcutaneous Fat

Insulates the body against cold temperatures

Protects muscles and bones from impact

Varies in thickness across different body areas

Visceral fat located?

deep within the abdominal cavity

surrounds internal organs like the liver, pancreas, and intestines

also known as intra-abdominal fat

Key characteristics of visceral fat

Not visible from the outside (unlike subcutaneous fat)

Contributes to the "apple-shaped" body profile

Linked to higher health risks (e.g., heart disease, type 2 diabetes, inflammation)

Overweight

Having extra body weight from:

Bone

Muscle

Fat

Body water

Overfat

Having too much body fat

May occur even if total body weight is normal

Obesity

An excessive and unhealthy amount of body fat

Waist circumference for male

> 40 inches (102 cm)

Waist circumference for females

> 35 inches (88cm) for females

How to calculate BMI

weight (kg) divide by height

make sure cm is in m

Physical activites

30-50%

Thermic effect of food

10%

Basal metabolism

50-65%

Factors that influence weight gain

Biological factors

Genetic factors

Childhood factors

Social factors

Diet

Leptin

Hormone produced by adipose

Reduces food intake and inhibits fat storage

Resistance develops in obesity

Ghrelin

Hormone from stomach

Stimulates eating behavior

↑ when hungry and ↓~1hr after eating

Not diminished with obesity

Roux-en-Y Gastric Bypass

Reduces stomach size and bypasses part of the small intestine

Sleeve Gastrectomy

Removes a portion of the stomach to reduce capacity

Gastric Banding

An adjustable band limits food intake

Benefits of physical activity

Reduces Risk of Type 2 Diabetes

Reduces Risk of Osteoporosis

Aerobic Exercise (3-5 times/week)

Raises heart rate for a more effective cardiovascular workout

Involves sustained, rhythmic contractions of large muscle groups

Examples: running, jogging, brisk walking, swimming

Resistance Exercise

Increases muscle mass and strength

Builds bone density

Examples: weightlifting, push-ups

Stretching Activities

Improve flexibility

Enhance range of motion and reduce injury risk

Proteins (amino acids) are NOT a significant fuel source during exercise

Carbohydrates:

Primary fuel for high-intensity activities

Fats

Used mainly during low-intensity activities

Recommended intake of carbohydrates

6-10g of CHO per kg of body weight per day

Anorexia Nervosa

Extremely restrictive eating behaviors

Intense fear of gaining weight or becoming "fat"

Distorted or unhealthful body image

Self-starvation or severe food restriction

Anorexia Nervosa Affected group

Most often occurs in adolescent or young adult females

Amenorrhea

absence of menstrual periods for at least 3 months

Bulimia Nervosa

An eating disorder characterized by repeated episodes of binge eating followed by purging behaviors to prevent weight gain.

Binge Eating:

Consuming a large amount of food in a short period of time

Often accompanied by a feeling of loss of control

Purging

Attempts to get rid of calories or food after binge eating, such as:

Self-induced vomiting

Misuse of laxatives or diuretics

Fasting for days after a binge

Excessive exercise

Physical signs of bulimia nervosa

Tooth decay and staining due to repeated exposure to stomach acid

Mouth sores and irritation from frequent vomiting

Calluses on the backs of hands or knuckles (known as Russell's sign) from self-induced vomiting

Swelling of the cheeks or jaw area caused by inflamed salivary glands due to frequent vomiting

When protein consumption exceeds body needs, and energy needs are met, the excess amino acids are metabolized and:

stored as fat

is 163cm tall and weighs 69kg. Based on her BMI, how is she classified?

Overweight

The thermic effect of food contributes approximately what percentage of total energy expenditure in a typical adult?

10

Which of the following decreases BMR?

sleep

Which of the following is a hormone produced by the stomach cells that promotes positive energy balance by stimulating appetite and promoting efficient energy storage?

ghrelin

What are vitamins?

Organic micronutrients essential for health

Regulate specific physiological processes

Not produced by the body in sufficient amounts

Prevent specific deficiency diseases

Naturally found in a variety of foods

Fat Soluble Viatmins

Includes Vitamins A, D, E and K

Absorbed into the lymph, then enter the bloodstream

Require protein or lipid carriers for transport

Can accumulate in the liver or adipose tissue

Needed in periodic doses

Water Soluble Vitamins

Include Vitamin C and the B vitamins

Absorbed directly into the bloodstream

Travel freely throughout the body

Excess amounts are excreted in urine

Must be consumed in frequent does (every 1-3days)

Vitamin Absorption

Not digested- would lose function if broken down

Absorbed primarily in the small intestine

Bioavailability varies- the body doesnt absorb 100% of what's in food

Factors Affecting Absorption

Enhanced absorption during pregnancy

Fat-soluble vitamins absorbed better with small amounts of dietary fat

Bile aids in fat-soluble vitamin absorption

Vitamin Descruction

Air

Excessive heat

Alkaline conditions

Light

Vitamin Conservation

Local fresh produce, eat fresh, reduce cooking times

Utilize microwave, steaming, stirfry

Add fats after cooking

Stored canned foods in cool place

Fat Soluble vitamin with three active forms

Retinol

Retinal

Retinoic Acid

Retinol (alcohol form)

Supports reproduction

Main storage and transport form

Can be converted to retinal or retinoic acid as needed

Found only in animal source

Retinal (aldehyde form)

Essential for vision

Retinoic acid

Acts as a hormone, regulating cell differentiation, growth, and embryonic development

Hyperkeratosis

excessive keratin production

Vitamin D

Prevents rickets (bone deformities in children)

Bone deformities can be reversed if treated early

Antioxidant Protection

Protects lipids from free radicals

Supports Cell Health

Maintains integrity of cell membranes

Protects Lipoproteins

Prevents LDL cholesterol oxidation

Vitamin E Sources

Nuts and Seed: sunflower seeds, almonds

Plant Oils: sunflower, safflower, olive oil

Vitamin K Characteristics

Stored in liver

Vitamin K Functions

1. Blood Clotting

Supports synthesis of clotting proteins

Key proteins: Prothrombin, Factors VII, IX, X

2.Bone Health

Assists in production of osteocalcin, a protein important for bone turnover

Key Roles of B Vitamins

Thiamin (B1)

Riboflavin (B2)

Niacin (B3)

Thiamin (B1):

Carbohydrate and branched-chain amino acid (BCAA) metabolism

Supports DNA and RNA production

Riboflavin (B2)

nvolved in oxidation-reduction reactions

Supports energy metabolism

Niacin (B3)

Carbohydrate and fatty acid metabolism

Supports energy metabolism

Power Player Deficiencies

Pellagra- Niacin Deficiency Key Symptoms; The 4 D;s

diarrhea

dermatitis

dementia

death

Thaimin (Vitamin B1)

Enriched breads and cereals

Other sources: Pork, Soymilk, Acorn sqaush, Pinto Beans, Watermelon

Riboflavin (Vitamin B2)

Enriched breads and cereals

Other sources: Milk, Yohurt, Milk Products

Note: Light exposure reduces riboflavin content in milk

Niacin (Vitamin B3)

Enriched breads and cereals

Other sources: Meat, Fish, Poultry, Nuts

Vitamin C

Powerful Antioxidant: Protects cells from oxidative damage

Supports Enzymes:Helps many enzymes function (not a

true coenzyme)

Dietary Need: Most animals synthesize it; humans &

guinea pigs must consume it

Vitamin C Functions

Synthesis and maintenance of collagen

• Fibrous protein that gives strength to connective tissue

Bile Production

Chemical components involved in nervous function

Hormone production

Vitamin C Sources

Citrus fruits

Bell peppers

____ are fat soluble vitamins

Vitamins A, K, E and D

What statement accurately reflects a key physiological difference between water-soluble and fat soluble vitamins?

Water-soluble vitamins generally require regular dietary intake due to limites storages, whereas fat soluble vitamins can accumulate in tissues and pose a risk of toxicity.

Which of the following does not result in vitamin destruction?

adding fats after cooking

Which combination of Vitamin A forms is involved in promoting vision and acting as a hormone?

Retinal and Retinoic acid

Rickets is mainly due to a deficiency of which of the following?

vitamin D

Which of the following enhances calcium absorption from the gastrointestinal (GI) tract?

vitamin D

Vitamin D can be made in the body with the help of:

sunlight

Which vitamin is synthesized in the intestine by bacteria?

vitamin K

Coenzymes are important because:

they enable the enzymes to function

Riboflavin if used by the body to:

facilitate energy metabolism

Which of the following is NOT a symptom of pellagra?

dizziness

Absorption of which of the following requires the presence of intrinsic factor?

vitamin B12

Water

An essential inorganic nutrient vital for life

Water Supports key body functionssuch as:

transport,

temperature control, metabolism, and waste

removal

Water makes up how much of total body weight?

50-70%

Lean muscle tissue- 73% water

Adipose (fat) tissue- 20% water

Intracellular Fluid

Inside cells

~2/3 of total body fluid (~28 L)

Extracellular Fluid

Outside cells (~1/3 of total body fluid, ~14 L)

− Interstitial fluid: Between cells in tissues

− Intravascular fluid (plasma): In blood & lymph — carries cells through circulation

Functions of Water

Transport & Removal

Metabolic Role

Universal Solvent

Circulatory Function

Temperature Regulation

Protection & Lubrication

Transport & Removal:

Carries nutrients and waste products throughout the body

Metabolic Role

Participates directly in many metabolic reactions

Universal Solvent

Dissolves minerals, vitamins, amino acids, glucose, and other essential molecules

Circulatory Function

Help maintain blood volume

Temperature Regulation

also maintaining normal body temperature

Protection & Lubrication

Cushions joints and vital areas such as the eyes, spinal corc, and amniotic sac arounda feturs

Fat-soluble substances must attach to or be

surrounded by water-soluble proteins for

transport.

Functions of Water: Acount for blood volume

Essential for maintaining healthful blood volume

BP increases when blood volume rises

Risk factor for CVD

Kidneys help to regulate blood volume and BP

Body Temperature

Help maintain body temperature.

− Water has a high heat capacity

Body fluid temperature remains

quite stable.

− Sweating releases heat

Evaporation of water from skin cools the skin and blood.

Functions of Water: Protection and Lubrication

Protect and lubricate body tissues.

− Cerebrospinal fluid protects the brain and spinal column.

− Amniotic fluid protects the fetus.

− Synovial fluid is a lubricant around joints.