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week1dbnutrion.pptxChapter 1 Food Choices: 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
Why Do We Eat the Way We Do?
Personal Preferences
Enjoyment
Nourishment
Age
Why Do We Eat the Way We Do?
Sensory Influences: Taste, Texture, and Smell
Flavor
Classic tastes: Sweet, sour, bitter, salty, and umami
Why Do We Eat the Way We Do?
Social, Emotional, and cognitive Influences
Habits
Comfort/Discomfort Foods
Advertising and Promotion
Eating Away from Home
Food and Diet Trends
Social Factors
Nutrition and Health Beliefs
Why Do We Eat the Way We Do?
Environmental Influences
Economics
Lifestyle
Availability
Cultural Influences
Religion
The Social Ecological Model
The American Diet
How healthful is the “American” diet?
Too few nutrient-dense foods
Fruits, vegetables, low-fat dairy, and whole-grain foods
Too much of the foods known to be harmful
Sodium, solid fat, saturated fat, and sugar
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
Six classes of nutrients
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
Carbohydrates
Sugars and starches
Functions
Energy source
Food sources
Grains
Vegetables
Legumes
Fruits
Dairy products
Introducing the Nutrients
Lipids
Triglycerides (fats and oils), cholesterol, and phospholipids
Functions
Energy source, structure, regulation
Food sources
Fats and oils
Meats
Dairy products
Some plant sources
Introducing the Nutrients
Proteins
Made of amino acids
Functions
Energy source, structure, regulation
Food sources
Meats
Dairy products
Grains, legumes, vegetables
Introducing the Nutrients
Vitamins
Functions
Regulate body processes
Play a vital role in extracting energy
Fat-soluble
A, D, E, K
Water-soluble
B vitamins, vitamin C
Food sources
All food groups
Introducing the Nutrients
Minerals
Macrominerals
Microminerals, or trace minerals
Functions
Structure, regulation
Food sources
All food groups
Introducing the Nutrients
Water
Most important nutrient
Functions
Temperature control
Lubrication of joints
Transportation of nutrients and wastes
Food sources
Beverages
Foods
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
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
Energy in Food
Be Food Smart: Calculate the Percentages of Calories in Food
Diet and Health
What does it mean to be healthy?
WHO defines health as “a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity”
Diet and Health
Disease is “an impairment of the normal state of the living animal … that interrupts or modifies the performance of the vital functions”
Food choices are most likely to affect our risk for developing chronic diseases
Diet and Health
Physical activity
Sedentary lifestyle
Risk factor for chronic disease
Role in long-term weight management
At least 30 minutes per day of moderate activity
Reduce chronic disease risk
At least 60 minutes per day
Weight-management
Applying the Scientific Process to Nutrition
The Scientific Process enables researchers to test the validity of hypotheses
Hypothesis: Proposed explanation made on the basis of limited evidence as a starting point for further investigation
Used to expand our nutrition knowledge
Applying the Scientific Process to Nutrition
Common study designs
Epidemiological studies
Animal and cell culture studies
Case control studies
Clinical trials
Randomized
Double-blind
Placebo-controlled
Steps of the Scientific Process
From Research Study to Headline
Publishing experimental results
Scientists publish results of experiments in scientific journals to communicate new information
Peer review process reduces chance that low-quality research is published
From Research Study to Headline
Sorting facts and fallacies in the media
Popular media may distort facts through omission of details
In-depth research article becomes 30-second sound bite
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”
