Figure 24.1b

Red meat, butter:use sparingly

Vegetables inabundance

Whole-grainfoods atmost meals

Daily excercise and weight control

(b) Healthy eating pyramid

Dairy or calcium supplement: 1–2 servings

White rice, white bread,potatoes, pasta, sweets:

use sparingly

Fish, poultry, eggs:0–2 servings

Nuts, legumes:1–3 servings

Fruits:2–3 servings

Plant oilsat most

meals

What are nutrients?What are nutrients? Essential substances that your body Essential substances that your body

needs in order to grow and stay healthyneeds in order to grow and stay healthy

What is a Nutrient?

Nutrients

• Some provide energy. • All help build cells and

tissues, regulate bodily processes such as breathing.

• No single food supplies all the nutrients the body needs to function.

Healthy Diets RequireHealthy Diets Require

Macronutrients• Water• Amino Acids and Proteins• Lipids• Carbohydrates

Micronutrients• Vitamins (B, C, A, D, E, K)• Minerals (Fe, Ca, P, Na, K)

Six categories of nutrients:

WateWaterr

Solvent in which the chemistry Solvent in which the chemistry of life occursof life occurs• cell chemistry occurs in an cell chemistry occurs in an

aqueous mediumaqueous medium• water carries essential nutrients water carries essential nutrients

to cellsto cells• water carries metabolic wastes water carries metabolic wastes

away from cellsaway from cells• hydrolysis & dehydration hydrolysis & dehydration

reactionreaction• stabilizes body tempstabilizes body temp

CarbohydratesCarbohydrates Energy MetabolismEnergy Metabolism

• Glucose is the fuel used by cells to Glucose is the fuel used by cells to make ATPmake ATP–Neurons and RBCs rely almost entirely Neurons and RBCs rely almost entirely

upon glucose upon glucose –Excess glucose is converted to glycogen Excess glucose is converted to glycogen

or fat and storedor fat and stored

CarbohydratesCarbohydrates

Dietary sources• Starch (complex carbohydrates) in grains

and vegetables• Sugars in fruits, sugarcane, sugar beets,

honey and milk• Insoluble fiber: cellulose in vegetables;

provides roughage• Soluble fiber: pectin in apples and citrus

fruits; reduces blood cholesterol levels

CarbohydratesCarbohydrates

Dietary requirementsDietary requirements• Minimum 100 g/day to maintain adequate Minimum 100 g/day to maintain adequate

blood glucose levelsblood glucose levels• Recommended minimum 130 g/day Recommended minimum 130 g/day • Recommended intake: 45–65% of total Recommended intake: 45–65% of total

calorie intake; mostly complex calorie intake; mostly complex carbohydratescarbohydrates

CarbohydratesCarbohydrates

Dietary FiberDietary Fiber• water-insolublewater-insoluble fiber adds bulk to fecal fiber adds bulk to fecal

matter facilitating its passage through and matter facilitating its passage through and elimination from the digestive systemelimination from the digestive system

• water-solublewater-soluble fiber may absorb dietary fiber may absorb dietary cholesterol, reducing its absorption by the cholesterol, reducing its absorption by the digestion tractdigestion tract

Soluble FiberSoluble Fiber Insoluble Fiber

Wheat Seed

Wheat Seed

Lipids

Dietary sources• Triglycerides

–Saturated fats in meat, dairy foods, and tropical oils

–Unsaturated fats in seeds, nuts, olive oil, and most vegetable oils

• Cholesterol in egg yolk, meats, organ meats, shellfish, and milk products

Lipids

Essential fatty acids• Linoleic and linolenic acid, found in

most vegetable oils

• Must be ingested

Essential uses of lipids in the bodyEssential uses of lipids in the body• Help absorb fat-soluble vitaminsHelp absorb fat-soluble vitamins

• Major fuel of hepatocytes and skeletal Major fuel of hepatocytes and skeletal musclemuscle

• Phospholipids are essential in myelin Phospholipids are essential in myelin sheaths and all cell membranessheaths and all cell membranes

Lipids

LipidsFunctions of fatty deposits (adipose

tissue)• Protective cushions around body organs

• Insulating layer beneath the skin

• Concentrated source of energy

LipidsLipids

Regulatory functions of prostaglandins• Smooth muscle contraction• Control of blood pressure• Inflammation

Functions of cholesterol• Stabilizes membranes• Precursor of bile salts and steroid

hormones

LipidsLipids

Dietary requirements suggested by the American Heart Association• Fats should represent 30% or less of total

caloric intake• Saturated fats should be limited to 10% or

less of total fat intake• Daily cholesterol intake should be no more

than 300 mg

Pathways of Lipid Metabolism

Atherosclerosis

normalnormal diseaseddiseased

• Cholesterol: <175 mg/dl• Triglycerides: blood fats, 30-175

mg/dl• HDL: Good cholesterol, > 35

mg/dl• LDL: Bad Cholesterol, <130

mg/dl• Chol/HDL ratio: < 4.5 indicates

heart disease

Your Cholesterol Level

Lowering Your Cholesterol Level

• Eat healthy

• Exercise

• Lose wt.

• Quit smoking

• 1 glass of wine or beer

• Medications (Lipitor)

ProteinsProteins

• Enzymes • Structural proteins (shape and

form of cells and tissues)• Hormones• Immunoglobulins (antibodies)

Essential Amino Essential Amino AcidsAcids

• Tryptophan• Methionine• Valine• Threonine

• Phenylalanine• Leucine• Isoleucine• Lysine• Arginine• Histidine

(infants)

ProteinsProteins

Dietary sources• Eggs, milk, fish, and most meats contain

complete proteins • Legumes, nuts, and cereals contain

incomplete proteins (lack some essential amino acids)

• Legumes and cereals together contain all essential amino acids

ProteinsProteins

Uses:• Structural materials: keratin,

collagen, elastin, muscle proteins

• Most functional molecules: enzymes, some hormones

ProteinsProteins

Use of amino acids in the bodyUse of amino acids in the body1.1. All-or-none ruleAll-or-none rule

– All amino acids needed must be All amino acids needed must be present for protein synthesis to occurpresent for protein synthesis to occur

2.2. Adequacy of caloric intakeAdequacy of caloric intake– Protein will be used as fuel if there is Protein will be used as fuel if there is

insufficient carbohydrate or fat availableinsufficient carbohydrate or fat available

ProteinsProteins

Nitrogen balanceNitrogen balance– State where the rate of protein synthesis State where the rate of protein synthesis

equals the rate of breakdown and lossequals the rate of breakdown and loss– Positive if synthesis exceeds breakdown Positive if synthesis exceeds breakdown

(normal in children and tissue repair)(normal in children and tissue repair)– Negative if breakdown exceeds Negative if breakdown exceeds

synthesis (e.g., stress, burns, infection, synthesis (e.g., stress, burns, infection, or injury)or injury)

Proteins

Hormonal controlsHormonal controls– Anabolic hormones (GH, sex Anabolic hormones (GH, sex

hormones) accelerate protein hormones) accelerate protein synthesissynthesis

Complete ProteinsVersus

Incomplete Proteins

Vegetarian diet may result in protein Vegetarian diet may result in protein deficiencydeficiency

Need essential amino acidsNeed essential amino acids• beans beans lysine & isoleucine lysine & isoleucine• corn corn tryptophan & methionine tryptophan & methionine

Transamination

VitaminsVitamins

Organic compounds needed by the Organic compounds needed by the body in small, but essential amountsbody in small, but essential amounts

Cannot be synthesized by the body in Cannot be synthesized by the body in sufficient amountssufficient amounts

Function in a variety of ways in Function in a variety of ways in metabolic reactionsmetabolic reactions

Thirteen known vitaminsThirteen known vitamins

Water-Soluble Water-Soluble VitaminsVitaminsVersus

Water-Insoluble Water-Insoluble VitaminsVitamins

Water-Soluble Water-Soluble VitaminsVitamins

Pantothenic acidPantothenic acid

BiotinBiotin

BB1212 (cyanocobalamin) (cyanocobalamin)

Folic acid Folic acid

B6 (pyridoxine)

C (ascorbic acid)

B1 (thiamin)

B2 (riboflavin)

Niacin

Water-Insoluble VitaminsWater-Insoluble Vitamins

MineralsMinerals

Essential inorganic elementsEssential inorganic elements Involved in a variety of Involved in a variety of

metabolic processesmetabolic processesMajor minerals versus trace Major minerals versus trace

mineralsminerals

Major Major MineralsMinerals

CalciumCalciumPhosphorusPhosphorusMagnesiumMagnesiumSodiumSodiumPotassiumPotassiumChlorineChlorine

Trace Trace MineralsMinerals

IronIodineFluorideZincCopper

Manganese

Cobalt

Selenium

Chromium

An animal whose diet is missing one or An animal whose diet is missing one or more essential nutrients.more essential nutrients.

Giraffe eats bone to get phosphorus nutrient

Malnourishment

Impaired cognitive Impaired cognitive developmentdevelopment

Won’t attain full heightWon’t attain full heightMore susceptible to disease More susceptible to disease

and infectionand infection

Malnourishment

Traditional Food in Hawaii

vs

• Approximately 24 million people in the US have diabetes (10%)

• Another 16 million have a condition now known as prediabetes

Diabetes Epidemic

Diabetes Diabetes MellitusMellitus

Type I Diabetes hyposecretion of insulininsulin dependantjuvenile onset

Type II Diabeteslate onset (adult)insensitivity of cells to insulinmanage by exercise & diet

• sugar in blood and urine

• urinate too often and produce too

much urine

• Too thirsty

• Too hungry

Symptoms (Type I):

• Arteriosclerosis

• Cardiovascular problems

- Heart disease

- Stroke

- High blood pressure

• Gangrene

• Blindness

• Kidney damage

Complications

• Insulin replacement

• Pancreas transplant

• Pancreatic cell transplant

• Fetal pancreatic islet cell transplant

Treatment:

2010: U.S. spends $170 Billion Annually

Per Person:

• Individuals with diabetes:

$13,243/year

• Individuals without diabetes:

$2,560/year

Cost $$$$

Obesity may be gene related Obesity may be gene related Leptin Leptin

leptin levels leptin levels appetite appetite - loss of body fat loss of body fat leptin levels and leptin levels and appetite appetite

and wt gainand wt gain potential medications for obesitypotential medications for obesity

ObesityObesity

Here are the top 5 obese countries:

• United States (34% of adults were overweight in 2008)

• Mexico (30% in 2006) • New Zealand (27% in 2007) • Australia (25% in 2007) • United Kingdom (25% in 2008)

Lowest: Japan & Korea 3.2%

ObesityObesity

Genetically Modified FoodsGenetically Modified Foods

Experts say 60% to 70% of processed foods on U.S. grocery shelves have genetically modified ingredients.

Common GM crops:• Soybeans• Corn • Cotton

Genetically Modified FoodsGenetically Modified FoodsConsCons

• Introducing allergens and toxins to food• Accidental cross pollination • Antibiotic resistance• Creation of "super" weeds and other

environmental risks

Genetically Modified FoodsGenetically Modified FoodsProsPros

• Increased pest and disease resistance• Grow food in harsh climate • Increased food supply (more food/acre)• More nutritional value• Make drugs

Ring spot virus

Artificial SweetenersArtificial Sweeteners

• Reduced calories• Reduce tooth decay• Diabetes• Lower cost

Artificial SweetenersArtificial Sweeteners

• Acesulfame potassium (Sunett, Sweet One)

• Aspartame (Equal, NutraSweet)• Neotame• Saccharin (SugarTwin, Sweet'N

Low)• Sucralose (Splenda)

Natural SweetenersNatural Sweeteners

• Agave• Corn syrup• Honey• Maple syrup• Sugar cane• Stevia

Aim for Fitness

1.Aim for a healthy weight

Ten U.S. Dietary Guidelines

2. Be physically active each day

Build a Healthy Base

3. Let the pyramid guide your choices

4. Choose a variety of grains daily, especially whole grains

5. Choose a variety of fruits and vegetables daily.

6. Keep food safe to eat.

Choose Sensibly7. Choose a diet that is low in

saturated fat and cholesterol and moderate in total fat 8. Choose beverages and foods to moderate your intake of sugars9. Choose and prepare food with less salt

10. If you drink alcoholic beverages do so in moderation

Coffee/Chocolate/Caffeine• Increases blood flow to brain• Increases memory• Lowers blood pressure• Lowers risk of heart disease• More alert and awake

INQUIRY

1. What are nutrients that the body needs but can’t synthesize on its own called?

2. Which cells of the body, under normal circumstances, must have energy in the form of glucose in order to survive?

3. How does the body make use of dietary cholesterol?

4. What is an incomplete protein?5. What trace element is necessary for wound

healing?6. Neural tube defects are easily prevented by the

adequate intake of ____ by pregnant mothers.7. What carbohydrate can be found in a steak?8. Hemorrhaging could occur because of lack of

sufficient vitamin _____.

Moment of Zen