figure 24.1b red meat, butter: use sparingly vegetables in abundance whole-grain foods at most meals...
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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
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
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
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