Download presentation
Presentation is loading. Please wait.
1
Chapter 1 Food Choices: Nutrients and Nourishment
2
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
3
Why Do We Eat the Way We Do?
Personal Preferences Enjoyment Nourishment Age
4
Why Do We Eat the Way We Do?
Sensory Influences: Taste, Texture, and Smell Flavor Classic tastes: Sweet, sour, bitter, salty, and umami
5
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
6
Why Do We Eat the Way We Do?
Environmental Influences Economics Lifestyle Availability Cultural Influences Religion
7
The Social Ecological Model
8
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
10
Introducing the Nutrients
Functions Normal growth and development Maintaining cells and tissues Fuel to do physical and metabolic work Regulating body processes
11
Introducing the Nutrients
Six classes of nutrients Carbohydrates Lipids (fats and oils) Proteins Vitamins Minerals Water
13
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
15
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
16
Introducing the Nutrients
Carbohydrates Sugars and starches Functions Energy source Food sources Grains Vegetables Legumes Fruits Dairy products
17
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
18
Introducing the Nutrients
Proteins Made of amino acids Functions Energy source, structure, regulation Food sources Meats Dairy products Grains, legumes, vegetables
19
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
20
Introducing the Nutrients
Minerals Macrominerals Microminerals, or trace minerals Functions Structure, regulation Food sources All food groups
21
Introducing the Nutrients
Water Most important nutrient Functions Temperature control Lubrication of joints Transportation of nutrients and wastes Food sources Beverages Foods
22
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
24
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
26
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
28
Introducing the Nutrients
Energy in Food Be Food Smart: Calculate the Percentages of Calories in Food
29
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”
30
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
31
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
33
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
34
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
35
Steps of the Scientific Process
36
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
37
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
39
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”
Similar presentations
