Chapter 1 Nutrients and Nourishment The Science of

Chapter 1 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? © Monkey Business Images/Shutter. Stock, Inc. • Personal preferences • Enjoyment • Nourishment • Age Figure 1. 1 Adventures in eating. Babies and toddlers are willing to try new things, generally after repeated exposure.

Why Do We Eat the Way We Do? • Sensory influences • Flavor • Describes both taste and smell • Texture also plays a part • Classic tastes: Sweet, sour, bitter, salty, and umami

• Social, emotional, and cognitive influences • Habits • Comfort/Discomfort Foods • Advertising and Promotion • Eating Away from Home • Food and Diet Trends • Social Factors • Knowledge of Health Figure 1. 3 Comfort foods. and Nutrition © Alena Ozerova/ Shutterstock, Inc. Why Do We Eat the Way We Do?

Why Do We Eat the Way We Do? • Environmental influences • Economics • Lifestyle • Availability • Cultural Influences • Religion

Figure 1. 8 A social-ecological framework for nutrition and physical activity decisions. Modified from: Centers for Disease Control and Prevention. <Insert Figure 1 -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

Table 1. 1 Average U. S. Consumption Compared to Recommendations, 2013 Reproduced from U. S. Department of Agriculture and U. S. Department of Health and Human Services. Dietary Guidelines for Americans, 2010. 7 th ed. Washington, DC: U. S. Government Printing Office; December 2010. <Insert Table 1. 1>

Introducing the Nutrients • Functions • Normal growth and development • Maintaining cells and tissues • Fuel to do physical and metabolic work • Regulating body processes

Introducing the Nutrients • Six classes of nutrients • Carbohydrates • Lipids (fats and oils) • Proteins • Vitamins • Minerals • Water

Figure 1. 9 The six classes of nutrients.

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

Figure 1. 10 Nutrients have three general functions in your body.

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

Figure 1. 11 Energy sources. Carbohydrate, fat, protein, and alcohol provide different amounts of energy per gram.

Introducing the Nutrients • Energy in foods • When is a kilocalorie a calorie? • Kilocalorie = 1, 000 calories • Units used to measure food energy • 1 kcal = Amount of energy it would take to raise the temperature of 1 kg of water by 1 degree Celsius

Introducing the Nutrients • How can we calculate the energy available from foods? • Carbohydrate yields 4 kcal for every gram • Protein yields 4 kcal for every gram • Fat yields 9 kcal per gram • 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 • Recommendations for adults • 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity aerobic activity per week • Muscle-strengthening activities on 2 or more days a week

Table 1. 3 Leading Causes of Death: United States

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 Figure 1. 12 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.

Figure 1. 14 Sorting facts and fallacies.

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. ”