PowerPoint Lecture slides prepared by Obaidur Rahman , PhD. North South University

1. PowerPoint Lecture slides prepared by ObaidurRahman, PhD. North South University

2. What is Nutrition? • Nutrition: the study of food, • including • How food nourishes our bodies • How food influences our health • Nutrition is a relatively new discipline of science.

3. What is Nutrition? • Early research in nutrition focused: • Link between nutrient deficiencies and illness • Vitamin C deficiency cause Scurvy.

4. 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

5. Why Is Nutrition Important? • Nutrition encompasses the following aspects of food • Consumption • Digestion • Absorption • Metabolism • Storage • Excretion

6. Why Is Nutrition Important? • Nutrition also studies these aspects of food • Psychological • Food safety • Global food supply • Cultural

7. Why Is Nutrition Important?

8. Why Is Nutrition Important? Obesity is a growing problem.

9. Why Is Nutrition Important? • Nutrition is so important that it has become a national goal • Goals of Healthy People • Prevent nutrient-deficiency diseases • Lower the risk for chronic diseases

10. What Are Nutrients? • Nutrients: the chemical in foods that are critical to human growth and function. • carbohydrates • fats and oils (two types of lipids) • proteins • vitamins • minerals • water

11. What Are Nutrients? SIX GROUPS OF ESSENTIAL NUTRIENTS Alcohol ??? Alcohol is a chemical commonly consumed in beverages and which may also be added to some foods as a flavoring or preservative. But it is not considered a nutrient because it is not critical for body functioning or the building or repairing of tissues. In fact, alcohol is considered to be both a drug and a toxin

12. 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 amount (µg or mg). • Vitamins and minerals

13. Energy from nutrients We measure energy in kilocalories (kcal). Calorie: amount of energy required to raise the temperature of 1 g of water by 1 °C. On food labels, “calorie” actually refers to kilocalories.

14. Carbohydrates • The primary fuel source for our body, particularly for our brain and for physical exercise. • Provide 4 kcal per gram • Carbohydrates are found in grains (wheat, rice), vegetables, fruits and legumes.

15. Fats and Oils • Are a type of lipids, a diverse group of organic substances that are insoluble in water. • Provide 6 kcal per gram • Are an important energy source during rest or low intensity exercise • Are found in butter, margarine, vegetable oils • Are source of fat-soluble vitamins, and essential fatty acids

16. Proteins • Are chains of amino acids • Can supply 4 kcal of energy per gram, but are not a primary energy source. • Are an important source of nitrogen

17. Proteins • Proteins are important for • Building cells and tissues • Maintaining bones • Repairing damage • Regulating metabolism • Fluid balance • Proteins are found primarily in meats and dairy products, but seeds, nuts, and legumes are also good sources, and we obtain small amounts from vegetables and whole grains.

18. Vitamins Vitamins: organic compounds that help regulate our body s functions. Vitamins are micronutrients that do not supply energy to our bodies.

19. Minerals • Minerals: inorganic substances because they do not contain carbon and hydrogen. • Some important dietary minerals are sodium, potassium, calcium, magnesium, and iron. • Minerals have many important functions in our body. They assist in fluid regulation and energy production, are essential to the health of our bones and blood, and help rid our body of the harmful by-products of metabolism.

20. 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…………

21. Determining Nutrients Needs • Dietary Reference Intakes (DRIs): update nutritional standards. • Expand on the traditional RDA values • Set standards for nutrients that do not have RDA values

22. Determining Nutrients Needs • DRIs identify the • Amount of a nutrient to prevent deficiency disease in healthy people • Amount of a nutrient which may include the risk of chronic disease • Upper level of safety for nutrients

23. Determining Nutrients Needs

24. Determining Nutrients Needs • The DRIs for most nutrients consist of four values: • Estimated Average Requirement (EAR) • Recommended Dietary Allowance (RDA) • Adequate Intake (AI) • Tolerable Upper Intake Level (UL)

25. Determining Nutrients Needs • Estimated Average Requirement (EAR) • The average daily nutrient intake level estimated to meet the requirement of half the healthy individuals in a particular life stage or gender group. • Scientists use the EAR to define the Recommended Dietary Allowance (RDA) for a given nutrient.

26. Determining Nutrients Needs Recommended Dietary Allowance (RDA) The average daily nutrient intake level that meets the nutrient requirements of 97 to 98% of healthy individuals in a particular life stage and gender group.

27. Determining Nutrients Needs • Adequate Intake (AI) • Recommended average daily nutrient intake level assumed to be adequate. • Based on observations or experiments involving healthy people, and it is used when an RDA cannot be determined • For nutrients having an AI value, including calcium, vitamin D, vitamin K, fluoride

28. Determining Nutrients Needs • Tolerable Upper Intake Level (UL) • Highest average daily nutrient intake level likely to pose no risk of adverse health effects to almost all individuals in a particular life stage and gender group • Our intake of a nutrient increases in amounts above the UL, the potential for toxic effects and health problems increases.

29. Determining Nutrients Needs • Estimated Energy Requirement (EER) • Average dietary energy intake that is predicted to maintain energy balance in a healthy adult. • The EER can be individualized according to a persons level of activity, age, gender, weight, and height, along with other factors

30. Determining Nutrients Needs • Acceptable Macronutrient Distribution Range (AMDR) • Proportion of energy intake that should come from each macronutrients. • The range of macronutrient intakes associated with a reduced risk for chronic disease. • A range of macronutrient intakes that provides adequate levels of essential nutrients

31. Calculating the energy contribution of carbohydrates, fats and proteins You have completed a personal diet analysis, and found out you need to consume 2500 kcal per day. From your diet analysis, you also find that you consume 300g of carbohydrates, 90g of fat and 123 g of protein. Do you think your diet is ok?

32. Nutrition Research • The scientific method: • Observation: describe the phenomenon • Create a hypothesis • Design, collect and analyze the data • Interpret the data • Generalize the finding, develop a theory

33. Nutrition Research

34. Research Models • Epidemiological studies- large population trends • Epidemiology  observational study • Epidemiology study indicate only relationship between factors, not specifically a cause-and-effect relationship • Example: Blood pressure values of physically active older adults are lower than those of inactive older adults

35. Research Models • Model System: • Humans are not very good experimental models because it is difficult to control for all of the variables that affect our lives. • Humans also have long life spans, so it would take a long time to determine the results of certain nutritional interventions. • Laboratory studies generally involve experiments with animals. • Animals with short reproduction times can be studied when researchers need to look at the effects of specific treatments over many generations. • Animal studies also are used to conduct research that is not acceptable to conduct with humans. For instance, it is possible to study nutritional deficiencies in animals by causing a deficiency and studying its adverse health effects over the life span of the animal. • Drawback: 1) results may not directly apply to humans • 2) ethical implications

36. Research Models • Human experiments (2 primary types) • Case control studies: • Case control studies are epidemiological studies done on a smaller scale. • They involve comparing a group of individuals with a particular condition (for instance, adults over age 65 with high blood pressure) to a similar group without this condition. • Clinical trials • Clinical trials are tightly controlled experiments in which an intervention is made to determine its effect on a certain condition. • Interventions may include medications, nutritional supplements, controlled diets, and exercise programs.

37. Research Study Factors • Clinical trials: • 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.

38. 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 administrated? • Was the experiment double blind?

39. Evaluating Media Reports • Is the report based on testimonials? • Are the claims too good to be true? • Prior to publication in reputable scientific journals articles undergo peer review • Experiments must be repeated to confirm or disprove the findings.

40. Reliable Sources of Information • Trustworthy experts • Registered dietitian (RD) • Licensed dietitian • Professionals with advanced degree(s) in nutrition • Medical doctor • Self study in details from pg 21-24

41. Nutrigenomics: Personalized Nutrition or Pie in the Sky? • Nutrigenomicsis a scientific discipline studying the interactions between genes, the environment, and nutrition • A key theory behind nutrigenomics is that our genes may respond to factors in our diet. • Evidence of Nutrigenomic: Agouti mice are normally yellow, obese, and prone to cancer and diabetes. In 2000, researchers found that, when they changed the mother s diet just before conception, they could turn off the agouti gene, and any offspring born to that mother would appear normal. • As you might know, a gene is a segment of DNA, a substance in cells that is responsible for passing on traits from parents to offspring. • The diet that the researchers fed the mother was high in a chemical that attached to the agouti gene and disabled it.

42. Alcohol

43. Alcohol Alcohols are chemical compounds structurally similar to carbohydrates, with one or more hydroxyl (OH) groups. Ethanol is the specific type of alcohol found in beer, wine, and distilled spirits, such as whiskey and vodka. It is a by-product of the fermentation process, in which yeast breaks down grains, fruits, or vegetables. • Question to be asked: • What makes excessive alcohol intake so dangerous? • Why is moderate alcohol consumption often considered healthful? • How can you tell if someone is struggling with alcohol addiction?

44. Moderate Alcohol Intake • Alcohol intake is usually described as drinks per day. • A drink is defined as the amount of a beverage that provides 1/2 fluid ounce of pure alcohol. • For example: • 12 oz of beer • 10 oz of a wine cooler • 4- 5 oz of wine • 1 and ½ oz of 80 proof whiskey, scotch, gin, or vodka are each equivalent to one drink

45. Moderate Alcohol Intake The 2005 Dietary Guidelines for Americans advise, Those who choose to drink alcoholic beverages should do so sensibly and in moderation defined as the consumption of up to one drink per day for women and up to two drinks per day for men. The Dietary Guidelines also identify groups of individuals who should not consume alcohol at all, including women who are or may become pregnant and women who are breastfeeding.

46. Benefits of Moderate Alcohol • In most people, moderate alcohol intake offers some psychological benefits: • it can reduce stress and anxiety while improving self-confidence. • It can also have nutritional benefits: in the elderly • a moderate use of alcohol can improve appetite and dietary intake • In addition, moderate alcohol consumption has been linked to lower rates of heart disease. • Alcohol increases levels of the good type of cholesterol (HDL) while lowering the • concentration of bad cholesterol (LDL); it also reduces the risk for abnormal clot formation in the blood vessels • Recently, there has been a lot of interest in resveratrol, which is a powerful antioxidant found in red wines and foods such as grapes and nuts. • Some researchers, based on experiments with mice, are proposing that resveratrol may be able to lower our risk for certain chronic diseases, such as diabetes, heart disease, and liver disease

47. Concerns of Moderate Alcohol • Ifresveratrolis found to be effective in promoting human health, the amount needed • would be so high that it would have to be given as a purified supplement, not in the form of red wine. • Not everyone responds to alcohol in the same manner. • A person s age, genetic makeup, state of health, and use of medications can influence both immediate and long-term responses to alcohol intake, even at moderate levels. • For example, some women appear to be at increased risk for breast cancer when consuming low to moderate amounts of alcohol. • As few as two drinks per day can increase the risk for hypertension (high blood pressure) in some people, especially if they consume the alcohol without food. • Moderate use of alcohol has also been linked to a higher rate of bleeding in the brain, resulting in what is termed hemorrhagic stroke

48. Concerns of Moderate Alcohol Alcohol has a relatively high caloric content (7 kcal/g). If you re watching your weight, you might be interested to know that a serving of wine is about 100 Calories, beer is about 150 Calories, and a typical margarita is over 300 Calories! What s more, unlike solid foods, alcoholic beverages fail to trigger the satiety, or fullness, response. So it’s not surprising that regularly consuming alcohol makes it difficult to avoid weight gain. Alcohol intake may also reduce your inhibitions, leading you to overeat!

49. Concerns of Moderate Alcohol Drug alcohol interactions is well known; many medications carry a warning label advising consumers to avoid alcohol while taking the drug. These include common over-the-counter pain remedies, such as acetaminophen, aspirin, and ibuprofen, which, when consumed with alcohol, are associated with gastrointestinal bleeding. Alcohol magnifies the effect of certain painkillers, sleeping pills, antidepressants, and antianxiety medications and can lead to loss of consciousness. In diabetics using insulin injections or oral medications to lower blood glucose (blood sugar), alcohol can exaggerate the drug s effect, leading to an inappropriately low level.

50. What happens to alcohol in the body? Most of the alcohol someone drinks is absorbed directly into the bloodstream from both the stomach and the small intestine; it does not have to be broken down first. Consuming foods with some fat, protein, and fiber slows the absorption of alcohol and can reduce blood alcohol concentration (BAC) by as much as 50% compared to peak BAC when drinking on an empty stomach. Carbonated alcoholic beverages are absorbed very rapidly, which explains why champagne and other sparkling wines are so quick to generate an alcoholic buzz. Women often absorb 30 -35% more of a given alcohol intake than do men of the same size, which may explain why women often show a greater response to alcohol compared to men. Anytime you consume more than one alcoholic beverage per hour, you are exposing every tissue in your body to the toxic effects of alcohol. On average, a healthy adult metabolizes the equivalent of one drink per hour. If someone drinks more than that, such as two or three alcoholic drinks in an hour, the liver is unable to keep up. The excess alcohol is released back into the bloodstream, through which it s distributed to all body fluids and tissues, including the brain.