Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. PowerPoint ® Lecture Slides prepared by James Bailey, University of Tennessee 1 C H A P T E R The Role of Nutrition in Our Health

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings What Is Nutrition? Nutrition: is an interdisciplinary and applied study of food, including  How food nourishes our bodies  How food influences our health (mind and body) Compared with other fields, nutrition is a relatively new discipline of science.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Why Is Nutrition Important? Nutrition contributes to wellness. Wellness: the absence of disease  Physical, emotional, and spiritual health Critical components of wellness  Nutrition  Physical activity

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Why Is Nutrition Important? Nutrition encompasses the following aspects of food  Consumption  Digestion  Absorption  Metabolism  Storage  Excretion

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Why Is Nutrition Important? Nutrition also studies these aspects of food  Psychological  Food safety  Global food supply  Cultural

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Why Is Nutrition Important? Figure 1.1

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Why Is Nutrition Important? Nutrition can prevent disease.  Nutrient deficiency diseases:  rickets (vitamin D)  goiter (iodine)  scurvy (vitamin C)  Diseases influenced by nutrition: heart disease; diabetes; high blood pressure; osteoarthritis, osteoporosis

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Figure 1.2 Why Is Nutrition Important? Obesity is a growing problem across the globe – changes in obesity that took developing world nations, such as the US two to four decades to occur are taking place in emerging nations at 2x the pace or faster!

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Promoting Better Nutrition for All The World Health Organization and member states began a campaign called: Five Keys to a Healthy Diet: 1. Give your baby only breast milk for the first six months of life; 2. Eat a variety of foods; 3. Eat plenty of fruits and vegetables; 4. Eat moderate amounts of fat and oils; 5. Eat less salt and sugars.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings What Are Nutrients? Nutrients: the chemicals in foods that are critical to human growth and function. carbohydratesvitamins fats and oilsminerals proteinswater

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings What Are Nutrients? Macronutrients: nutrients required in relatively large amounts (g or Kg).  Provide energy  Carbohydrates; fats and oils; proteins Micronutrients: nutrients required in smaller amounts (  g or mg).  Vitamins and minerals

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Energy from Nutrients We measure energy in kilocalories (kcal) or kiloJoules (kJ). On food labels in America, the term “calorie” appears. It should actually state: kilocalories.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Carbohydrates  Primary source of fuel for the body, especially for the brain  Provide 4 kcal (or 17 kJ) per gram  Carbohydrates are found in grains (wheat, rice), vegetables, fruits, and legumes  Sugars are also carbohydrate

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Fats and Oils  Are composed of lipids, molecules that are insoluble in water  Provide 9 kcal (38 kJ) per gram  Are an important energy source during rest or low intensity exercise  Are found in butter and vegetable oils  Are source of fat-soluble vitamins and essential fatty acids

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Proteins  Are chains of amino acids  Can supply 4 kcal (17 kJ) of energy per gram, but are not a primary energy source  Are an important source of nitrogen

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Proteins Proteins are important for  Building cells and tissues  Maintaining bones  Repairing damage  Regulating metabolism  Fluid balance Protein sources include meats, fish, dairy products, seeds, nuts, and legumes.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Vitamins Vitamins: organic molecules that assist in regulating body processes. [Organic means that the molecule contains carbon atoms.] Vitamins are micronutrients needed to support the body. They do not yeild energy, so they have no kcal or kJ in them. There are two categories: 1.Fat-soluble vitamins 2.Water-soluble vitamins

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Vitamins Fat-soluble vitamins  Vitamins A, D, E, and K  Dissolve easily in fats and oils Fat-soluble vitamins can be stored in the body. Toxicity can occur, especially from vitamin A.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Vitamins Water-soluble vitamins  Vitamin C and the B vitamins  Remain dissolved in water Excess water-soluble vitamins are eliminated by the kidneys daily and cannot be stored in our bodies. This is why we must eat more of these vitamins each and every day.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Minerals Minerals: inorganic substances required for body processes. They are atoms, not molecules. Minerals include, for example: sodium, calcium, iron, potassium, and magnesium. Minerals have many different functions such as fluid regulation, bone structure, muscle movement, and nerve functioning.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Minerals Our bodies require at least 100 mg/day of the major minerals such as calcium, phosphorus, magnesium, sodium, potassium, and chloride. We require less than 100 mg/day of the trace minerals such as iron, zinc, copper, iodine, and fluoride.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Water Water is a critical nutrient for health and survival. Water is involved in many body processes. fluid balance nutrient transport nerve impulses removal of wastes muscle contractions chemical reactions many, many more…

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Determining Nutrient Needs Dietary Reference Intakes (DRIs): updated nutritional standards.  Expand on the traditional RDA values  Set standards for nutrients that do not have RDA values

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Determining Nutrient Needs DRIs identify the  Amount of a nutrient needed to prevent deficiency disease in healthy people  Amount of a nutrient which may reduce the risk of chronic disease  Upper level of safety for nutrients

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Determining Nutrient Needs Figure 1.8

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Determining Nutrient Needs DRIs consist of four values 1.Estimated Average Requirement (EAR) 2.Recommended Dietary Allowances (RDA) 3.Adequate Intake (AI) 4.Tolerable Upper-Intake Level (UL)

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Determining Nutrient Needs Estimated Average Requirement (EAR)  The average daily intake level of a nutrient that will meet the needs of half of the people in a particular category  Are used to determine the Recommended Dietary Allowance (RDA) of a nutrient

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Determining Nutrient Needs: EAR Figure 1.9

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Determining Nutrient Needs Recommended Dietary Allowances (RDA)  The average daily intake level required to meet the needs of 97 to 98% of people in a given life stage and gender

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Determining Nutrient Needs: RDA Figure 1.10

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Determining Nutrient Needs Adequate Intake (AI)  Recommended average daily intake level for a nutrient  Based on observations and estimates from experiments  Used when the RDA is not yet established: calcium, vitamin D, vitamin K, fluoride

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Determining Nutrient Needs Tolerable Upper Intake Level (UL)  Highest average daily intake level that is not likely to have adverse effects on the health of most people  Consumption of a nutrient at levels above the UL is not considered safe

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Determining Nutrient Needs Estimated Energy Requirement (EER)  Average dietary energy intake (kcal) to maintain energy balance  Based on age, gender, weight, height, and level of physical activity

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Determining Nutrient Needs Acceptable Macronutrient Distribution Ranges (AMDR)  The portion of the energy intake that should come from each macronutrient  The range of energy intake from carbohydrate, fat, and protein associated with reduced risk of chronic disease  The range of macronutrient intake that provides adequate levels of essential nutrients

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Determining Nutrient Needs: AMDR Table 1.4

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Nutrition Research The scientific method  Observation: describe the phenomenon  Create a hypothesis  Design, collect, and analyze the data  Interpret the data  Generalize the findings, develop a theory

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Research Models  Epidemiological studies  Human experiments  Case control studies  Clinical studies  Animal studies Note: Each type of study has advantages and disadvantages.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Research Study Factors  Controls  Does not receive treatment  Sample size  Appropriate to measure a difference between treatment groups  Placebo  Similar appearance and taste  Double-blind  Neither subjects nor researchers know who is in the placebo or treatment groups

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Evaluating Media Reports Ask these questions to determine the scientific validity  Who is reporting the information?  Who conducted the research and who paid for it?  Is the report based on reputable research studies?  Was there a control and an experimental group?  Was the sample size large enough to rule out chance variation?  Was a placebo effectively administered?  Was the experiment double blind?