Download Dietary Reference Intakes (DRIs)

Chapter 5: ​Nutrition
Understanding Nutritional Guidelines
● Dietary Reference Intakes (DRIs)
​
:
Umbrella term for four sets of dietary recommendations
○ Suggested intake levels of essential nutrients
for
optimal health
● Recommended Dietary Allowance
​ (RDA):
Represents the average daily amount of any one nutrient to
protect against nutritional deficiency
● Acceptable Macronutrient Distribution Range
​ (AMDR):
Intake levels of essential nutrients that provide adequate
nutrition and reduce risk of chronic disease
Understanding Nutritional Guidelines
● Dietary Guidelines ​ for Americans: scientifically based diet
and exercise recommendations
● ​ USDA MyPlate: graphic nutritional tool that translates DRIs
and Dietary Guidelines into healthy food choices
​ ● Daily Values: standards used on food labels to indicate how a
particular food contributes to the recommended daily intake of
major nutrients in a 2,000-calorie diet
Types of Nutrients
● ​ Essential nutrients: needed to build, maintain, and repair
tissues and regulate body functions
​
● Macronutrients: needed in large amounts
○ Water, carbohydrates, proteins, fats
​
● Micronutrients: needed in small amounts
○ Vitamins, minerals
Summary:
Water—The Unappreciated
Nutrient
● Function:
○ Digests,
absorbs,
transports
nutrients
○ Helps regulate
body
temperature
○ Carries waste
out of the
body
○ Lubricates our body parts
● Fluid balance: right amount of fluid inside and outside each
cell; maintained by ​electrolytes
​
Riverside’s Water – Riverside Public Utilities
http://www.ewg.org/tap-water/whats-in-yourwater.php
Riverside’s Water – Eastern Municipal Water District
http://www.ewg.org/tap-water/whats-in-yourwater.php
Water—The Unappreciated Nutrient
● In most places in U.S. tap water is of equal or superior quality
to bottled water
● RDA:
○ 1 to 1.5 milliliters per calorie spent
○ 2 to 3 liters, or 8 to 12 cups of fluid
○ Water needs can vary depending on several factors,
such as foods consumed and activity level
Summary:
Carbohydrates—Your Body’s Fuel
● The body’s main source of energy
○ Fuel most of the body’s cells during daily activities
○ Used by muscle cells during high-intensity exercise
○ Only source of energy for brain cells, red-blood cells,
and some other types of cells
● Types:
○ Simple carbohydrates (sugars)
○ Complex carbohydrates (starches and dietary fibers)
● RDA:
○ 130 grams for males and females (aged 1–70)
Simple and Complex Carbohydrates
● Simple carbohydrates:
○ Easily digestible and composed of one or two units of
sugar
■ Glucose, fructose, galactose, lactose,
maltose, sucrose
● Glucose travels to liver where it can be stored as glycogen for
future energy needs
● Too many simple carbohydrates leaves you with a “sugar
high”, followed by a feeling of depletion, and a craving for
more sugar
○ Added sugars have even more dramatic effect
■ High fructose corn syrup (HFCS)
● Artificial sweeteners touted as alternative
○ Safety concerns; effect on appetite and insulin
Simple and Complex Carbohydrates
●
Complex carbohydrates:
○ Composed of multiple sugar units including starches
and dietary fiber
● Sources:
○ Whole grains (whole wheat, brown rice, oatmeal,
corn)
○ Vegetables; some fruit
● Whole grains preferred over refined carbohydrates (white flour
products)
○ Provide more nutrients
○ Slow digestive process
○ Make you feel full longer
Summary:
Fiber
●
●
●
●
Fiber
●
●
●
Summary:
Dietary fiber: complex carbohydrate found in plants that
cannot be broken down by the digestive tract
Fiber allows for passage of food quickly through the
intestines, which helps prevent hemorrhoids and
constipation
Soluble fiber dissolves in water and lowers cholesterol
Insoluble fiber passes through digestive tract unchanged;
serves as natural laxative
RDA:
○ 25 grams/day for women (aged 19-50)
○ 38 grams/day for men (aged 14-50)
Fiber is best obtained through diet, not pills or supplements
Sources of fiber:
○ Fruits
○ Vegetables
○ Dried beans
○ Peas and other legumes
○ Cereals
○ Grains
○ Nuts
○ Seeds
Protein—Nutritional Muscle
● Function:
○ Build and maintain muscles, bones, and other body
tissues
○ Form enzymes that facilitate chemical reactions
○ Constructed from 20 different amino acids
■ Essential amino acids must be supplied by
foods
● Types:
○ Complete proteins
○ Incomplete proteins
● RDA:
○ 0.36 grams per pound of body weight
Protein—Nutritional Muscle
● Complete protein sources
○ Animal proteins: meat, fish, poultry, milk, cheese,
eggs
● Incomplete protein sources
○ Vegetable proteins: grains, legumes, nuts, seeds,
other vegetables
● Complementary proteins: proteins that in combination provide
essential amino acids
● Mutual supplementation: nutritional strategy of combining two
incomplete protein sources to provide a complete protein
○ For example, beans and rice
Fats—A Necessary Nutrient
● Principal form of stored energy in the body
○ Provide essential fatty acids
○ Role in the production of other fatty acids and Vitamin
D
○ Provide the major material for cell membranes and for
the myelin sheaths that surround nerve fibers
○ Assist in absorption of fat-soluble vitamins
○ Affect texture, taste, and smell of foods
○ Provide emergency reserve when we are sick or
when our food intake is diminished
● RDA:
○
– 20–35% of calories from fat with only about
one-third coming from saturated fats
Summary:
Types of Fat
● Saturated fat: Found in animal products and other fats that
remain solid at room temperature
○ Beef
○ Pork
○ Poultry
○ Whole-milk dairy products
○ Certain tropical oils (coconut and palm)
○ Certain nuts (macadamia)
Types of Fat
● Monounsaturated fat: found primarily in plant sources, are
liquid at room temperature, and are semisolid or solid when
refrigerated
○ Olive, safflower, peanut and canola oils
○ Avocados
○ Many nuts
● Polyunsaturated fat: commonly referred to as “oil”; liquid at
room temperature and when refrigerated
○ Corn and soybean oils
○ Fish, including trout, salmon, and anchovies
Cholesterol
● A waxy substance that is needed for several important body
functions
● The body produces it from the liver and obtains it from animal
food sources (meat, cheese, eggs, milk)
● Too much cholesterol can clog arteries and lead to
cardiovascular disease
● LDLs (low density lipoproteins) are the “bad” cholesterol,
while HDLs (high density lipoproteins) are considered “good”
● Recommended: consume no more than 300 milligrams per
day
Trans Fats
● Liquid vegetable oils that have been chemically changed
through the process of hydrogenation to extend the shelf life of
processed foods
● Pose a risk to cardiovascular health by raising LDL levels and
lowering HDL levels
● Foods high in trans fatty acids include:
○ Crackers, cookies, chips
○ Cakes and pies
○ Doughnuts
○
Summary:
Deep fried foods like French fries
Omega-3 and Omega-6 Fatty Acids
● Omega-3s: contain alpha-linolenic acid, which helps slow the
clotting of blood, improves arterial health, and lowers blood
pressure
●
Omega-6s: contain linolenic-acid and are important to health,
though they are often consumed too much by Americans
How much FAT?
● 20-35% of your daily caloric intake
○ Less than ⅓ from saturated fats (7-10%... 22 grams)
Minerals—A Need for Balance
● Minerals are naturally occurring substances needed by the
body in small amounts
○ Build strong bones and teeth, and help carry out
metabolic processes and body functions
● The body needs 20 essential minerals
○ Macrominerals (need at least 100 mgs/day)
■ Calcium, chloride, magnesium,
phosphorous, potassium, sodium
○ Microminerals (need less than 100 mgs/day)
■ Chromium, cobalt, copper, fluorine, iodine,
iron, zinc, manganese, nickel, and others
● A balanced diet provides all the essential minerals the body
needs per day
Vitamins—Small But Potent Nutrients
● Naturally occurring organic substances needed by the body in
small amounts
● Serve as catalysts for releasing energy from carbohydrates,
proteins, and fats while maintaining other body
components
● Your body needs at least 11 specific vitamins
○ A, C, D, E, K, and the B-complex vitamins
● Vitamins can be found in a variety of foods, so often
supplements are unnecessary
Summary:
Key Vitamins and Minerals
Overview of RDIs: Recommended Daily Intakes of Macronutrients and
Micronutrients
Other Substances in Food: Phytochemicals
● Phytochemicals: substances naturally produced by plants
● May keep cells healthy, slow tissue degeneration, prevent
carcinogens, reduce cholesterol, protect heart, maintain
hormone levels, keep bones strong
● Three important types of phytochemicals:
○ Antioxidants: neutralize free radicals
○ Phytoestrogens: lower cholesterol and reduce risk of
heart disease
○ Phytonutraceuticals: may inhibit growth of cancer and
heart disease
Summary:
The Color Wheel of Foods
Dietary Guidelines for Americans
● Two-thirds of Americans are now overweight or obese
● Focus is on stopping and reversing the spread of overweight
and obesity
● Approaches to change:
○ Individual
○ Environmental
○ Food supply
Dietary Guidelines for Americans
●
Four main goals:
○ Reduce calorie intake and increase physical activity
○ Move toward a more plant-based diet composed of
nutrientdense foods
○ Reduce intake of foods containing added sugars and
solid fats and reduce overall sodium and refined grain
consumption
○ Meet the 2008 ​Physical Activity Guidelines provided
by the U.S. Department of Health and Human
Services
Summary:
2010 Dietary Guidelines for Americans: Key Messages
Dietary Guidelines for Americans
● MyPlate: visual icon designed to raise awareness and health
literacy about the different food groups
○ Emphasize foods high in nutrient density
● Individual calorie requirements are calculated based on sex
and age at three activity levels:
○ Sedentary: only light physical activity
○ Moderately active: equivalent to walking 1.5 miles per
day at 3–4 mph
○ Active: more than 3 miles per day at 3–4 mph
Summary:
MyPlate
Estimated Calorie Requirements
---------->
Dietary Guidelines for
Americans
● DASH Eating Plan:
Dietary Approaches
to Stop
Hypertension
● Recommendations
for specific groups
○ Children
and
adolescents
○ Older adults
○ Pregnant and breastfeeding women
○ Overweight adults and children
○ People with chronic conditions
● Limit red meat consumption
○ Link to heart disease, cancer, and diabetes
Summary:
Vegetarian Diets
● Vegetarian diets may offer protection against obesity, heart
disease, high blood pressure, diabetes, digestive disorders,
and some forms of cancer
● Vegetarians need to make sure their diets provide the energy
intake and food diversity necessary to meet dietary guidelines
Daily Values on Food Labels
● FDA regulates food labels
● List serving size and number of servings
● Give total calories and calories from fat
○ Look for foods with no more than 30 percent of their
calories from fat
● Show how much the food contributes to Daily Values for
important nutrients
● Shows % of Daily Value: recommended daily intake of
specified nutrients
Nutrition Facts Food Label
Front-of-Package Food Labels
● FDA’s authority to regulate health claims on front-of-package
(FOP) food labels is limited
○ Institute of Medicine found these labels provide little
guidance and cause confusion
■ 12 different symbols, logos, and icons
● Recommended a standard for FOP labels
Summary:
Recommended FOP Labels
Proposed Changes to the Nutrition Facts Label
● 2014 proposed changes to Nutrition Facts label for
packaged food
○ Mandated inclusion of information on added sugars
○ Updated reference amounts
○ Specified calorie and nutrition information based on
whole package not just serving size
○ Information on potassium and vitamin D in packaged
food equired
○ Altered label format to emphasize calories, serving
size, and Percent Daily value
Restaurant Menu Labels
● 2010 Patient Protection and Affordable Care Act includes new
requirement: all chain restaurants provide calorie labeling on
their menus
● Preliminary research suggests consumers are no more likely
to choose healthier menu items
Current Consumer Concerns
● Overconsumption of soft drinks
● High-sodium diets
● Food allergies and food intolerances
○ Eight foods responsible for 90% of allergies: milk,
eggs, peanuts, tree nuts, shellfish, soy, and wheat
○ Food intolerances such as lactose intolerance are
less severe
● Gluten-free diets
○ Celiac disease: immune reaction to gluten which is
found in wheat, barley, rye, and triticale
● Overconsumption of energy bars and energy drinks
Summary:
Current Consumer Concerns
● Probiotics, prebiotics, and synbiotics
○ Probiotics are living bacteria that may aid digestion;
prebiotics are nondigestible carbohydrates
that fuel probiotics
○ Synbiotics combine the two
○ Scientific studies have not confirmed health benefits
● Fast foods
● Food deserts: low-income areas where more than 500 people
or 33% have low access to a supermarket
○ When fresh produce not available, people don’t have
opportunity to choose a healthy diet
Fast-Food Meal
--------->
Organic Foods
●
Plant foods grown
without synthetic
pesticides or fertilizers
● Animal foods raised on
organic feed without
antibiotics or growth
hormone
● USDA regulates labeling
● Research has not demonstrated health benefits, but
environmental benefits are clear
○ Look for foods that are not only organic but also
locally grown
○ Wash organic produce thoroughly
Foodborne Illnesses
● Food intoxication: food poisoning in which food is
contaminated by natural toxins
○ Botulism
● Food infection: food poisoning in which food is contaminated
by disease-causing microorganisms, or pathogens
○ E. coli, salmonella, campylobacter
○ Pet food can contain salmonella
● Use safe food practices and store food safely, especially
leftovers
Summary:
Kitchen Safety
Genetically Modified Foods
● Genetically modified
(GM) organisms:
genetic makeup has
been changed to
produce desirable results
○ Selective breeding
○ Modern biotechnology faster and more refined
● Many crops are already GM
● Sixty percent of processed foods in supermarkets contain
one or more GM ingredient
● Safety assessed by FDA’s Center for Food Safety and Applied
Nutrition (CFSAN)
WRAP - UP
Summary: