A&P Chapter 24 - Nutrition

What BMI is Considered Obese?

30 or greater

Obesity

Significantly overweight

One of greatest health problems in U.S.

% of Adults with Obesity

42%

% of Children with Obesity

18.5%

Excess Body Fat Risks

Premature death, type 2 diabetes, hypertension, cardiovascular disease, stroke, osteoarthritis, and certain types of cancer

Body Mass Index (BMI)

Weight in kg divide by height in m^2

Healthy BMI

18.5 to 24.9

Overweight BMI

25.0 to 29.9

Obese BMI

30.0 to 39.9

Extremely (Morbid) Obese BMI

40.0 and higher

Nutrients

Required component of food that performs a physiological function in the body

Provides energy, promotes growth and development, and regulates cellular metabolism

Types of Nutrients

Carbohydrates, proteins, lipids, minerals, and vitamins

Carbohydrates

Either simple or complex

Glucose

Simple sugar

Brain cells require this as an energy source

What do Body Cells use as an Energy Source?

Fatty acids

What are Complex Carbohydrates Digested to?

Glucose

Refinement of Grains

Fiber is removed, along with vitamins and minerals

What Products Should be Minimized in the Diet?

Any product made from refined grains, such as white bread, cake, and cookies

Sources of Complex Carbohydrates

Beans, peas, nuts, fruits, and whole-grain products

*Good sources of vitamins, minerals, and fiber

Insoluble Fibers

Adds bulk to the feces and stimulates movements of the large intestine, preventing constipation

Soluble Fibers

Combines with bile salts and cholesterol in the small intestine and prevents them from being absorbed

Can Carbohydrates be Harmful?

High intake of refined carbohydrates and fructose sweeteners contribute to obesity

*have a high glycemic index, because they quickly increase blood glucose

What does the Pancreas Produce when Blood Glucose Rises Rapidly?

Insulin to bring the glucose levels down

What can Chronically High Insulin Levels Lead to?

Insulin resistance, type 2 diabetes, and increased fat deposition

Proteins

Made of 20 different amino acids

How Many Essential Amino Acids?

8 total

*must be attained through diet

Complete Proteins

Contain all essential amino acids

Usually derived from animal sources

*Non-animal sources of complete proteins are tofu, soymilk, and other processed food from soybeans

Incomplete Proteins

Plant sources

Need to combine them to get all essential amino acids

*Must ingest essential amino acids every day; they are not stored in the body

Can Proteins be Harmful?

Overabundance of intake can result in dehydration during exercise

Can lead to calcium loss in urine, which can lead to kidney stones

Eating red meat can lead to cardiovascular disease since it is high in saturated fats

Lipids

Include fats, oils, and cholesterol

Saturated Fats

Usually of animal origin

Solid at room temp

ex. butter, fat in meat, coconut oil, and palm oil

Unsaturated Fats

Don't promote cardiovascular disease

Usually liquid at room temp

ex. corn oil and safflower oil are high in polyunsaturated fatty acids

Polyunsaturated Oils

Contain the essential fatty acids linoleic acid and linolenic acid

Monounsaturated Fatty Acids

Olive oil and canola oil

Omega-3 Fatty Acids

Preserve brain function and protect against heart disease

ex. Flaxseed and cold-water fish

Can Lipids be Harmful?

Risk for cardiovascular disease is increased by a diet high in saturated fats and cholesterol

Atherosclerotic Plaques

Formed from saturated fats and limit blood flow

2 Transport Proteins that Carry Cholesterol in Blood

High-density lipoprotein (HDL)

Low-density lipoprotein (LDL)

High-density Lipoprotein (HDL)

"Good" lipoprotein

Ends up in the liver, where the cholesterol is metabolized

Low-density Lipoprotein (LDL)

"Bad" lipoprotein

Ends up being deposited in the tissues

Trans Fatty Acids (Trans Fats)

Arise when unsaturated fatty acids are hydrogenated to produce a solid fat

Found in commercially packaged goods, such as cookies and crackers

If something contains partially hydrogenated vegetable oil, it contains trans fats

Minerals

Divided into major minerals and trace minerals

Major Minerals

Needed at quantities greater than 100 mg per day; trace, less than 100 mg

In cells and body fluids

Structural components of tissues

Trace Minerals

Part of larger molecules

ex. iron is present in hemoglobin, and iodine is a part of thyroid hormones

zinc, copper, and manganese are present in enzymes

Major Minerals Include

Calcium

Phosphorus

Potassium

Sulfur

Sodium

Chloride

Magnesium

Trace Minerals Include

Zinc

Iron

Copper

Iodine

Selenium

Manganese

Lack of Minerals

Occasionally individuals do not receive enough iron, calcium, magnesium, or zinc in their diets

A varied and complete diet usually supplies enough of each type of mineral

Why do Females Need More Iron in Their Diet?

They lose hemoglobin each month during menstruation

Calcium

In bones, teeth

Needed for nerve impulse conduction, muscle contraction and blood clotting

Calcium supplements prevent osteoporosis

Vitamin D is needed with calcium to prevent bone loss.

Osteoporosis

Degenerative bone disease common in the elderly

Sodium

Regulates water balance

Important in movement of materials across plasma membrane as well as conduction of a nerve impulse

Excess sodium can worsen hypertension

Recommended Amount of Sodium Intake

Recommended amount per day is 1,500 mg

Average American takes in more than 3,400 mg

Vitamins

Organic compounds.

Used for metabolism

Need to ingest, since they are not produced in high enough quantities by the body

Are often parts of coenzymes

How Many Vitamins are There?

13 total

2 Types of Vitamins

Fat-Soluble

Water-Soluble

Fat-Soluble Vitamins

Vitamins A, D, E, and K

Water-Soluble Vitamins

Vitamins C, B1, B2, niacin, folic acid, B6, B12, biotin, etc.

Antioxidants

Decrease the rate of oxidation or transfer of electrons

Defend body against free radicals

*common in fruits and vegetables

Free Radicals

Generated from cellular metabolism

Damages cells and tissues

Most Common Free Radicals in Cells

Superoxide and Hydroxide

Antioxidant Examples

Vitamins C, E, and A

Vitamin D

Skin cells contain precursor converted to this vitamin after UV exposure

Where is Vitamin D First Modified?

Kidneys and then liver until it becomes calcitriol

Calcitriol

Promotes absorption of calcium by intestines

What does Lack of Vitamin D Lead to?

Rickets

*most milk fortified with Vitamin D to prevent

Rickets

Bowing of legs, caused by defective mineralization of skeleton

Basal Metabolism

Number of calories a body burns at rest to maintain normal body functions.

*Depending on exercise levels, someone may need more calories beyond the rate

*A person cannot become overweight without taking in more calories than needed

How to Plan Nutritious Meals

Limit number of calories to an amount used daily

Include foods from all groups

*Eat more of these foods: fruits, vegetables, whole grains, and fat-free or low-fat milk products

*Choose lean meats, such as poultry, and fish high in omega-3 fatty acids, such as salmon, trout, and herring

*Include oils rich in monounsaturated and polyunsaturated fatty acids

*Eat less of foods high in saturated or trans fats, added sugars, cholesterol, salt, and alcohol

*Be physically active every day

Maximum Number of Daily Calories for Women Without Exercise

2000 calories

Maximum Number of Daily Calories for Men Without Exercise

2500 calories

Eating Disorders

Have social, cultural, emotional, and biological roots

Anorexia Nervosa

Bulimia Nervosa

Binge-Eating Disorder

Muscle Dysmorphia

Anorexia Nervosa

Psychological disorder

Fear of getting fat

Usually results in self-induced starvation, high physical activity, and may include purging

Bulimia Nervosa

Eat large amounts of high-calorie food (binge-eating) followed by purging to avoid weight gain

Binge-Eating Disorder

Overeating without purging

Stress, anxiety, anger, and depression can contribute

Common in the obese

Muscle Dysmorphia

Thinks his or her body is underdeveloped

Excess body-building

A preoccupation with diet and body form

May spend hours in the gym every day

*affects men more