1. Food Choices: Nutrients and Nourishment Chapter 1

2. What Is Nutrition? -The study of how your body uses the food that you eat.

3. You Are What you Eat!!

4. Nutrients and Nourishment The science of nutrition Identifies amount of food we need Recommends best food sources Provides helpful and harmful components  Helps us make better choices Improves our health Reduces our risk of disease Increases our longevity

5. Nutrients and Nourishment Why do we eat the way we do?  Food choices  Ways we use food  Food preferences  Inborn and environmental Sensory Cognitive © Andy Lim/ShutterStock, Inc.

6. Influences on Food Choices Sensory Influences  Taste Sweet, sour, bitter, and salty Umami  Smell  Texture  Color, moisture, and temperature

7. Influences on Food Choices Physiological changes  Accompany aging process  Teeth and gum deterioration  Bone loss  Diminished taste sensitivity

8. Influences on Food Choices Cognitive influences  Habits  Comfort/discomfort foods  Cravings  Advertising and promotion  Social factors  Nutritional value and health beliefs

9. Influences on Food Choices Environmental  Economic factors  Lifestyle  Culture Religion  The “American diet” Photo © PhotoDisc

10. Influences on Food Choices Economic factors  Where you live and climate Food that is accessible Food cost  Limited finances shift food choices  Does a healthier diet cost more?

11. Influences on Food Choices Lifestyle  Fast-paced society  Eating away from home  Convenience foods  Main dishes made from scratch

12. Influences on Food Choices Cultural influences  Human relationships  Culture defines our attitude Knowledge Beliefs  Customs  Habits  Symbolic

13. Influences on Food Choices Cultural influences  Religion Part of some rites, symbols, and customs  Cultural cuisine Increase in cultural interactions Increase in exposure to various cuisines

14. Influences on Food Choices Cultural influences  The “American diet” “Typical” is as diverse as Americans themselves Heavy on meat and potatoes Light on fruits and whole grains Eating more cereals, snack foods, soft drinks, and noncitrus juices

15. Introducing the Nutrients Definition of nutrients  Food = mixture of chemicals  Essential chemicals = nutrients

16. What is a Nutrient A nutrient is a chemical substance in food that helps maintain the body. Some provide energy. All help build cells and tissues, regulate bodily processes such as breathing. No single food supplies all the nutrients the body needs to function.

17. Introducing the Nutrients Other chemicals in food  Flavors and colors  Caffeine  Phytochemicals Plant chemicals Important health functions

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

19. Introducing the Nutrients General functions of nutrients  Supply energy Carbohydrates, lipids, and proteins  Contribute to cell and body structure  Regulate body processes

20. 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

21. Carbohydrates: Provide a source of energy for the body When taken in they are broken down into glucose and distributed through the blood stream Simple: are sugars = rapidly absorbed = insulin spikes Complex: are starches = slow to absorb= more dense

22. Introducing the Nutrients Carbohydrates  Sugars and starches  Functions Energy source  Food sources Grains Vegetables Legumes Fruits Dairy products Photo © PhotoDisc

23. Fats: Most concentrated source of energy Found in both plant and animal sources Saturated: animal products = limited intake Unsaturated: Plant source = “good fats’ Trans fats: Man made = = worst kind

24. 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 Photo © PhotoDisc

25. Introducing the Nutrients Proteins  Made of amino acids  Functions Energy source, structure, regulation  Food sources Meats Dairy products Grains, legumes, vegetables Photo © PhotoDisc

26. Proteins: Proteins are complete structures that consist of smaller molecules called amino acids. These are the building blocks of the body Essential – cannot be made in the body so must be taken in through diet Non Essential- can be made in the body or taken in through diet

27. Introducing the Nutrients Vitamins  Fat-soluble A, D, E, K  Water-soluble B vitamins, vitamin C  Functions Regulation  Food sources All food groups Photo © PhotoDisc

28. Introducing the Nutrients Minerals  Macrominerals and trace minerals  Functions Structure, regulation  Food sources All food groups Photo © PhotoDisc

29. Introducing the Nutrients Water  Most important nutrient  Functions Temperature control Lubrication of joints Transportation of nutrients and wastes  Food sources Beverages Foods Photo © PhotoDisc

30. Introducing the Nutrients Nutrients and energy  Energy sources  Measure of energy Kilocalorie

31. The calorie is a pre-SI metric unit of energy. It was first defined by Nicolas Clément in 1824 as a unit of heat.SImetric Nicolas Clément In most fields its use is archaic, having been replaced by the SI unit of energy, the joule. However, in many countries it remains in common use as a unit of food of energy. Specifically, a calorie is the amount of energy, or heat, it takes to raise the temperature of 1 gram of water by 1 degree Celsius (1.8 degrees Fahrenheit). One calorie is equal to 4.184 joules, a common unit of energy used in the physical sciences

32. Calories per gram: Protein 1 Gram = 4 calories Carbohydrates 1 Gram = 4 calories Fat 1 Gram = 9 calories

33. Introducing the Nutrients Energy in foods  Measured in kilocalories (kcal)

34. Introducing the Nutrients How can we calculate the energy available from foods?  Example 30 g carb x 4 kcal/g = 120 kcalories 10 g protein x 4 kcal/g = 40 kcalories 16 g fat x 9 kcal/g = 144 kcalories TOTAL = 304 kcalories

35. Introducing the Nutrients Be food smart  Managing the percent of macronutrient intake  Example To limit fat intake to 20–35% of total energy intake: 2,000 kcal food x 0.35 = 700 kcal from fat 700 kcal from fat/9 kcal/g = 77.8 g of fat allowed per day

36. Variables which affect nutrient needs: 1. Age 2. Gender 3. Activity Level 4. Climate 5. Health 6. State of nutrition

37. Introducing the Nutrients Obesity: public health crisis  65% of U.S. adults are overweight or obese  Increases health risks Type 2 diabetes Cardiovascular diseases Cancer Gallbladder disease

38. Introducing the Nutrients Obesity: public health objectives  Reduce prevalence of obesity to 15%  Factors that influence obesity Behavior Environment Genetics Images © Ryan McVay/Photodisc/Getty

39. Applying the Scientific Process to Nutrition Scientific method See Figure 1.11 on page 20  Observation  Hypothesis  Experimentation  Publication  Further experimentation  Theory

40. Applying the Scientific Process to Nutrition Types of studies  Epidemiological  Animal  Cell culture  Human Case control Clinical trial Placebo effect

41. From Research Study to Headline Publishing experimental results  Peer reviews of scientific journals Media publication  Sorting facts and fallacies  Finding reliable sources