Ch09 nutrition

Chapter 9Nutrition

Nutrition

• A diet is one’s usual pattern of food choices.• Poor diet is a risk factor for serious chronic

diseases that are major killers of Americans, such as:– Cardiovascular disease– Diabetes– Obesity– Certain cancers

Basic Nutrition PrinciplesWhat are Nutrients?

– Substances in food needed for growth, repair, and maintenance of cells.

– Classes• Carbohydrate: supplies energy• Fats: supply energy• Proteins: provide material for growth & repair• Vitamins: help regulate body processes• Minerals: help regulate body processes• Water: transports materials/chemical reactions

Basic Nutrition PrinciplesWhat are Non-Nutrients?

– Naturally occurring substances in foods that have no nutritional value, but still provide beneficial effects on the body.

– Phytochemicals may be beneficial to health. – Antioxidants: prevent or reduce the formation of

free radicals, which are unstable and highly reactive atoms or compounds that can cause cellular damage.

Basic Nutrition PrinciplesNatural, Health, Organic and Functional Foods

– Natural foods are minimally processed and contain no artificial additives such as synthetic colors or flavors

– Organic: foods without the use of man-made pesticides and fertilizers

– Functional foods, or nutraceuticals, are manufactured foods that have scientifically established medicinal benefits that are not provided by nutrients.

– Probiotics are live bacteria that may benefit health.

Basic Nutrition PrinciplesWhat Happens to the Food you Eat?

1. Digestion2. Absorption3. Energy


1. Digestion• process of breaking down complex food

molecules into nutrients that the body can use.• Enzymes speed up chemical reactions and

participate in the process of digestion


2. Absorption• the passage of nutrients through the walls of the

intestines and eventually, into the bloodstream• Water-soluble nutrients - dissolve in water and

are processed by the kidneys, excess are excreted in the urine.

• Fat-soluble nutrients - stored in the liver and body fat; therefore, they can accumulate and reach toxic levels.


3. Energy• Metabolism refers to all of the chemical

changes (reactions) that take place within the body.

• Carbohydrates (4cal/gram), fats(9cal/gram), proteins (4cal/gram), and alcohol (7cal/gram) (a non-nutrient)

• A calorie is a unit of energy.• The body cannot extract energy from vitamins,

minerals, and water.

Energy-Supplying NutrientsCarbohydrates

– Sugars - mono and disaccharides– Starches - glucose, fructose, sucrose and

lactose• Glucose (blood sugar) is the most important

monosaccharide in the body. • Dietary fiber - cannot be digested by the small

intestines• Carbohydrates should makeup 55% to 65% of

calories, primarily from starchy, high-fiber foods. (NOT Accurate)


– Carbohydrates and Health• Diabetes Mellitus

–carbohydrates are not metabolized properly because the body produces little or no insulin

–Without insulin, cells cannot carry out their metabolic activities properly and, as a result, glucose builds up in the blood.

–can lead to chronic health complications including vision damage, kidney disease, and circulatory problems



–Type 1»Caused by an autoimmune disease,

require daily insulin injections because the pancreas does not produce insulin.



–Type 2»Usually those with excess body fat or poor

diet»Can be controlled with diet and exercise


– Carbohydrates and Health• Metabolic Syndrome

–Excess abdominal fat and at least two of the following: hypertension, high blood glucose, high fat levels, and low HDL cholesterol levels.

–C-reactive protein - compound in blood that’s an indicator of inflammation, tends to be high

–Exercising, high fiber-rich foods, and maintaining a healthy body weight


– Carbohydrates and Health• Lactose Intolerance

–Inability to digest lactose, the sugar in milk, and experience intestinal symptoms as a result (bloating, cramps, and diarrhea).

–It is important for lactose-intolerant people to consume alternate calcium-rich foods


– Carbohydrates and Health• Fiber and Health

–Fiber provides some important health benefits. (See Table 9-3)

– Decreases risk of heart disease, can prevent constipation, infrequent or difficult bowel movements, & diverticulosis.

–25g/day

Energy-Supplying Nutrients

Energy-Supplying NutrientsLipids

– Triglycerides and cholesterol– Some dietary fat is necessary for health– More concentrated form of calories (9 vs. 4)– Mono/polyunsaturated vs. saturated


– Lipids and Health• High fat = weight gain• Saturated fat = high blood cholesterol and

cardiovascular disease• Unsaturated fat = lower risk of heart disease• Omega-3: reduce heart disease risk and

improve joint mobility• Mediterranean vs. Western diets


- Trans Fats• Trans fatty acids are produced when vegetable

oil is chemically changed through a process known as hydrogenation. They act like saturated fats in the body

- Fat Substitutes• Olestra, Oatrim, and Simplese• May produce unpleasant side effects and

interfere with the absorption of certain vitamins

Energy-Supplying Nutrients

Lipids– Setting Limits

• The typical American diet contains too much fat.• Fat intake should be reduced to no more than

35% of total calories (the intake of saturated fat should be no more than 10% of total calories), and one should limit cholesterol intake to 300 mg or less per day.

Energy-Supplying NutrientsProteins

– Build, maintain, and repair cells– Made up of amino acids– 11 non-essential 9 essential

• Animal proteins vs plant proteins– Proteins and Health

• Typical American consumes about 14% to 18% of his or her total calories from protein.


– Proteins and Health• Food Allergies

– A food allergy is the result of the immune system’s inappropriate response to harmless proteins (allergens) in foods.

– Proteins in cow’s milk, eggs, peanuts, tree nuts, wheat, soybeans, fish, and shellfish are most likely to cause allergic reactions.


– Proteins and Health• Celiac Disease

–Autoimmune Disease - Hypersensitivity to gluten, a protein in wheat, rye, and barley.

–Causes inflammation of the lining of the small intestine, damaging the lining, and the body cannot absorb nutrients from food as a result.

Non-Energy-Supplying NutrientsVitamins

– Needed to regulate growth; release energy from carbohydrates, fats, and proteins; and maintain tissues.

– Do not supply energy to the body– Fat-soluble vs. water soluble– Antioxidants

• protect the chemical structure of polyunsaturated fatty acids from the destructive effects of certain substances called free radicals

• Vitamin E, C, Beta Carotine

Non-Energy-Supplying NutrientsMinerals

– A group of elements, such as calcium, iron, and sodium.

– They have a wide variety of roles in the body– Calcium

• most plentiful mineral in the body• Low intake increases risk for osteoporosis• Estrogen stimulates bones to maintain their

mass and retain calcium.• Vitamin D and magnesium are also important

for bone health.

Non-Energy-Supplying NutrientsMinerals

– Iron• Most of the iron in the body is found in

hemoglobin, the substance in blood that transports oxygen. Cells need oxygen to release the energy stored in glucose.

• Premenopausal women are at risk of iron-deficiency

• People with anemia often report feeling tired because their cells are unable to obtain adequate amounts of energy

Non-Energy-Supplying Nutrients

Minerals– Iron

• Hemochromatosis is an inherited condition that increases the intestinal absorption of dietary iron.

–Individuals with this condition often are unaware that they have excessive amounts of iron in their blood, which can damage organs.

Non-Energy-Supplying NutrientsWater

– Essential for life – Dissolve and transport materials, eliminate

wastes, lubricate joints, and participate in chemical reactions.

– Dehydration is a serious and potentially life-threatening condition.

– Most people can maintain fluid and mineral balance by eating a variety of foods and drinking water before and during the activity

The Basics of a Healthful Diet• Most foods are mixtures of nutrients.• Foods that contain considerable calories from fat and

sugar often are called “junk” foods, but are better termed “empty-calorie” foods.

• To obtain a nutritious diet, people should eat a variety of foods daily.

• Nutritional adequacy and balance are the two key features of a nutritious diet.

• “Everything in moderation” is the best approach to planning nutritionally adequate and well-balanced diets.

The Basics of a Healthful Diet

Nutrient Requirements and Recommendations– Nutrient Requirements - minimum amount that

prevents an average person from developing the nutrient's deficiency disease

– To set an RDA for a nutrient, scientists take the required level of a nutrient and add an extra amount to provide a margin of safety.


The Dietary Guidelines– The Dietary Guidelines are a list of general dietary

and physical activity recommendations that are issued by the U.S. Department of Agriculture (USDA) that provides general recommendations for a healthful diet

The Basics of a Healthful DietThe Dietary Guidelines

– Balance calories with physical activity to achieve and maintain a healthy weight.• Prevent and/or reduce excess body fat by

improving dietary practices and increasing physical activity.

• Control total calorie intake to manage body weight. For people who are overweight or obese, consume fewer calories.

• Increase physical activity and reduce time spent being inactive.


– Foods and Food Components to Reduce• Limit sodium intake to less than 2300 mg/day.• Less than 10% of calories from saturated fats• Less than 300 mg of cholesterol daily• Avoid foods that contain trans fatty acid intake• Reduce intake of calories from foods that

contain solid fats, added sugars & refined grains

• Limit alcohol intake to up to one drink per day (women) and two drinks per day (men).


– Foods and Food Components to Increase• Increase vegetable and fruit intake.• Eat a variety of colorful vegetables• Consume at least half of all grain products as

whole grains• Increase intake of fat-free or low-fat milk and

milk products or substitutes, such as yogurt, cheese, or fortified soy beverages.


– Foods and Food Components to Increase• Choose protein foods from a variety of sources. • Increase the amount and variety of fish and

shellfish. • Replace solid fats with vegetable oils. • Choose foods that provide more potassium,

dietary fiber, Calcium, Vitamin D.


The Dietary Guidelines– Building Healthy Eating Patterns

• Select an eating pattern that meets nutrient and energy needs over time.

• Account for all foods and beverages consumed and evaluate the nutritional quality of your eating pattern.

• Prepare, eat, and store foods by following food safety recommendations to reduce risk of foodborne illnesses.

The Basics of a Healthful DietUsing Nutritional Labeling

– Almost all packaged foods are required to carry nutritional labels.

– Consumers can use food labeling to determine and compare the nutritional values of foods and to determine the percent of the Daily Values (DVs) each nutrient provides.

– People should seek to keep their daily intake of fat, saturated fat, cholesterol, and sodium below daily values, which represent the maximum one should be consuming daily.


What about Foods Sold in Restaurants?– In 2010, the U.S. federal government passed

legislation that required restaurants and food vendors with more than 20 locations to inform consumers about caloric and nutrient contents of products sold at these outlets.


Do You Need Vitamin or Mineral Supplements?– By selecting a variety of foods and eating

recommended amounts from all food groups, healthy adults should obtain enough nutrients without supplementation.

– Pregnant and breastfeeding women, some vegetarians, and the elderly can benefit from taking extra amounts of certain vitamins and minerals.

– “Insurance Policy.”

Malnutrition: Undernutrition and Overnutrition

– Malnutrition results when diets supply inadequate or excessive amounts of nutrients.

– There are two general types of malnutrition: undernutrition and overnutrition.• Undernutrition occurs when a diet does not

contain enough nutrients.–15% of US households

• Overnutrition results from consuming excessive amounts of nutrients.

Across the Life SpanNutrition

– Parents can teach their children how to choose more nutrient-dense foods.• Eating a nutritious breakfast is an important

habit to establish in childhood.– Adolescents often become overly concerned about

body size and shape and as a result may experiment with dietary supplements or limit nutritious foods in an effort to lose weight.

Across the Life SpanNutrition

– Elderly persons may consume poor diets because they have limited incomes or conditions such as arthritis that make it difficult to prepare meals.• Depression and loneliness may also contribute

to the poor nutritional status of some aged individuals.

• Many communities offer special feeding programs for the elderly such as Meals on Wheels.

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