Transcript Chapter 1: Food Choices: Nutrients and Nourishment

So What is Nutrition?
1. The science of foods and their components
(nutrients and other subjects), including the
relation ship to health and disease; processes
within the body (ingestion, disgestion,
absorption, transport, disposal) and the social,
economic, cultural and psychological
implications of eating.
Definitions you need to know!
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Essential vs. nonessential nutrients
Organic vs inorganic foods
Organic vs inorganic nutrients
Macro vs micro nutrients
Phytochemicals
Antioxidants
Nutrients and Nourishment
• The science of nutrition
• Identifies amount of food we need
• Recommends best food sources
• Identifies components in food that are
helpful or harmful
– Helps us make better choices
• Improves our health
• Reduces our risk of disease
• Increases our longevity
Nutrients and Nourishment
• Why do we eat the way we do?
– Food preferences
• Enjoyment
• Nourishment
• Age
© Andy Lim/ShutterStock, Inc.
Influences on Food Choices
• Sensory influences and personal
preferences
– Taste, texture, and smell
• Flavor
• Classic tastes: sweet, sour, bitter, salty,
and umami
– Habits
– Comfort/discomfort foods
• Behavioral motives
Influences on Food Choices
• Sensory influences
– Advertising and promotion
– Food and diet trends
– Social factors
– Nutrition and health beliefs
Courtesy of the Milk Processor Education Program.
Influences on Food Choices
• Environment
– Where you live
– How you live
– Who you live with
– Obesogenic environment
• Living in an environment that promotes
the overconsumption of calories and
discourages physical activity and calorie
expenditure
Influences of Food Choices
• Environment
– Economics
• Where you live and the surrounding
climate
– Lifestyle
• Foods prepared away from home
– Availability
• Poor access to nutritious foods
Influences of Food Choices
– Cultural influences
• Tradition or cultural background
– Religion
• Religious rites, symbols, and customs
– Social-ecological model
• Dietary Guidelines for Americans
• Individual factors, environmental
settings, various sectors of influence,
and social and cultural elements of
society
The American Diet
Reproduced from US Department of Agriculture and US
Department of Health and Human Services. Dietary Guidelines
for Americans, 2010. 7th ed. Washington, DC: US Government
Printing Office; December 2010.
The American Diet
Reproduced from US Department of Agriculture and US
Department of Health and Human Services. Dietary Guidelines
for Americans, 2010. 7th ed. Washington, DC: US Government
Printing Office; December 2010.
How healthful is the “American” diet?
-Too little nutrient-dense foods
• Nutrient density is a ratio of nutrient content (in grams) to the energy
content (in Kcalories). Nutrient-dense food is opposite to energydense food (also called “empty calorie" food). Nutrient-dense foods
provide substantial amounts of vitamins and minerals and relatively
few calories. Fruits and vegetables are the nutrient-dense, while
products containing added sugars, processed cereals, and alcohol
are not.
– Too much of the foods known to be harmful
• Sodium, solid fat, saturated fat, and sugar
Photo © PhotoDisc
Introducing the Nutrients
• Nutrients
– Functions
• Normal growth
and development
• Maintaining cells
and tissues
• Fuel to do
physical and
metabolic work
• Regulating body
processes
Introducing the Nutrients
• Nutrients
– Essential nutrients
• Body cannot make them,
or cannot make enough
– Six classes of nutrients
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Carbohydrates
Lipids (fats and oils)
Proteins
Vitamins
Minerals
Water
Introducing the Nutrients
• Definition of nutrients
– Absence from the diet results in a specific
change in health
– Putting the chemical back in the diet will
reverse the change in health
– Not only chemicals in food
• Phytochemicals
• Antioxidants
Introducing the Nutrients
• Classifications of nutrients
– Macronutrients
• Carbohydrates, lipids, and proteins
– Micronutrients
• Vitamins and minerals
– Organic (contain carbon)
• Carbohydrates, lipids, proteins, and vitamins
– Inorganic
• Minerals and water
Introducing the Nutrients
• Nutrients and energy
– Energy
• The capacity to do work
– Energy sources
• Carbohydrates, lipids, protein
– Measure of energy
• Kilocalorie
–1,000 calories = 1 kilocalorie
Introducing the Nutrients
• Energy in foods
– Measured in kilocalories (kcal)
Introducing the Nutrients
• Energy in foods
– When is a kilocalorie a calorie?
• Calorie
• Kilocalorie
–Specific measurement or unit of
energy in food
–General term for energy in food
Introducing the Nutrients
• How can we calculate the energy
available from foods?
– Example
30 g carb × 4 kcal/g = 156 kcalories
10 g protein × 4 kcal/g = 40 kcalories
16 g fat × 9 kcal/g = 144 kcalories
TOTAL = 340 kcalories
Introducing the Nutrients
• Be food smart
– Calculating the percent of calories in food
To limit fat intake to 20–35% of total energy
intake:
2,000 kcal food × 0.35 = 700 kcal from fat
700 kcal from fat/9 kcal/g = 77.8 g of fat allowed
per day
Diet and Health
• Health
• Disease
– Acute
• Short-lived illnesses
– Chronic
• Diseases with a slow onset and long
duration
Diet and Health
Diet and Health
• Obesity: public health crisis
– More than two-thirds of U.S. adults are
overweight or obese
– Increases health risks
• Coronary heart
disease
• Cancer
• Diabetes
• Hypertension
• Metabolic
syndrome
Diet and Health
• Obesity
– Factors that influence obesity
• Behavior
–Calorie imbalance
• Environment
–Barriers to or opportunities for an
active lifestyle
• Genetics
–Role of heredity
Applying the Scientific Process
to Nutrition
• Scientific process
– Test hypothesis
• Common study designs
– Epidemiological studies
– Animal studies
– Cell culture studies
– Case control studies
– Clinical trials
• Randomized
• Double-blind
• Placebo-controlled
Evaluating Information on the Internet
• There are no rules for posting on the
Internet
• Consider the source
• Keep in mind the scientific method
• Be on the lookout for “junk science”