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Dive into the science of nutrition, essential elements of food, and healthy eating behaviors. Learn about obtaining essential nutrients, caloric intake trends, protein requirements, carbohydrates, fiber benefits, fats, and ways to assess your dietary needs for optimal health.
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Assessing Eating Behaviors • What drives us to eat? • Hunger • Appetite • Cultural and social meaning of food • Habit or custom • Emotional Comfort • Convenience and advertising • Nutritional value • Social interactions
Eating for Health • Nutrition • The science of the relationship between physiological functions and essential elements of food • Calorie • Unit of measure that indicates the amount of energy we obtain from a food • Americans consume more calories per person than any other group of people in the world • Americans eat more fat (38%) than recommended by nutritionists (no more than 30%)
Eating for Health • Characteristics of a healthy diet • Adequate • Moderate • Balanced • Varied • Nutrient dense
Trends in Caloric Intake and Food Figure 9.1
Obtaining Essential Nutrients • Digestive process • Sequence of functions by which the body breaks down larger food particles into smaller, more usable forms • Our bodies cannot synthesize some essential nutrients • Some essential nutrients obtained from food
The Digestive Process Figure 9.2
Water • Dehydration – abnormal depletion of body fluids • The major component of blood • Necessary for • Electrolyte and pH balance • Transporting cells and O2 • Recommended amount – 8 glasses/day (64 ounces) • 50-60% of body is water • Is bottled water better?
Protein • Second most abundant substance in humans • Key to every cell, antibodies, enzymes, and hormones • Transport oxygen and nutrients • Role in developing/repairing bone, muscle, skin • Vital for human life • May need additional protein if fighting off infection, recovering from surgery or blood loss, recovering from burns
Proteins • Amino acids • Building blocks of protein • 20 essential amino acids must be obtained from food • 11 non-essential amino acids produced by the body • Link together to form • Complete protein – supplies all essential amino acids • Incomplete protein – may lack some amino acids, but these can be easily obtained from different sources • Few Americans suffer from protein deficiencies • Can you give examples of complete proteins?
Complementary Proteins Figure 9.3
Calculating Your Protein RDA Figure 9.4
Carbohydrates • Best fuel – provide energy quickly and efficiently • Two types • Simple sugars • Glucose (monosaccharide) – most common form • Fructose (monosaccharide) – found in fruits and berries • Sucrose (disaccharide) – sources include granulated sugar, milk and milk products • Complex carbohydrates (polysaccharides) • Starches – from flour, pasta, potatoes • Stored in the body as glycogen • Fiber
Carbohydrates • Carbohydrates and athletes • Sugar may be counterproductive • CHO ingestion is necessary for competitive long events • Carbohydrate loading • Myth of sugar addiction • Not related in long-term studies • Moderation is the key
Carbohydrates and Weight Loss • High protein/low carb diets • Helped educate the public about nutrients, importance of • Whole grains • Fiber • Low-sugar food choices
Fiber • “Bulk” or “roughage” • Indigestible portion of plants • Insoluble • Found in bran, whole-grain breads, most fruits and vegetables • Found to reduce risk for several forms of cancer • Soluble • Oat bran, dried beans, some fruits and vegetables • Helps lower blood cholesterol levels • Helps reduce risk for cardiovascular disease
Fiber • Offers many health protections • Colon and rectal cancer • Breast cancer • Constipation • Diverticulosis • Heart Disease • Diabetes • Obesity • Most American eat far less than recommended • Recommended is 20-30 grams and average is 12 grams
Fats • Also called lipids • Misunderstood but vital group of basic nutrients • Maintain healthy skin • Insulate body organs • Maintain body temperature • Promote healthy cell function • Carry fat-soluble vitamins A, D, E, and K • Are a concentrated form of energy
Obtaining Essential Nutrients • Triglycerides make up 95% of total body fat • Remaining 5% composed of substances like cholesterol • Can accumulate on inner walls of arteries and contribute to cardiovascular disease • Ratio of cholesterol HDL/LDL helps determine risk for heart disease • Saturated vs. unsaturated fat • Saturated mainly from animal sources, solid at room temperature • Unsaturated generally come from plants and usually liquid at room temperature
Percentages of Saturated, Polyunsaturated, and Monounsaturated Fats in Common Vegetable Oils Figure 9.5
Obtaining Essential Nutrients • Avoiding trans fatty acids • Created by process of making liquid oil into a solid • Increase LDL levels while lowering HDL levels • Higher risk of coronary and heart disease, sudden cardiac death • Found in many margarines, baked goods and restaurant deep-fried foods • Food labels listing no trans fasts can still contain less than 500 milligrams/serving
Obtaining Essential Nutrients • Still need essential fatty acids • Eat fatty fish • Use healthier oils (including olive oil) • Eat green leafy vegetables • Walnuts, walnut oil • Ground flaxseed
Obtaining Essential Nutrients • Use moderation with fat intake • Read food labels • Use olive oil for cooking • Avoid margarine with trans fatty acids • Choose lean meat, fish, poultry • Eat fewer cold cuts, less bacon, sausages, hot dogs, organ meats • Choose nonfat dairy products • Use substitutes for higher-fat products • Think of your food intake as an average, over a day or two—if you have a heavy breakfast, eat a light dinner
Vitamins • Potent, essential, organic compounds • Promote growth, help maintain life and health • Two types • Fat soluble – absorb through intestinal tract with fat • A, D, E, and K • Water soluble – dissolve in water • B-complex and C
Vitamins • Few Americans suffer from vitamin deficiencies • Often, vitamin supplements not necessary • Too much of many vitamins can be harmful • Why do you think so many people take vitamin supplements?
Minerals • Inorganic, indestructible elements that aid the body • Vitamins cannot be absorbed without minerals • Macrominerals are needed in large amounts • Sodium, calcium, phosphorus, magnesium, potassium, sulfur, chloride • Trace minerals are needed in small amounts • Iron, zinc, manganese, copper, iodine • Excesses or deficiencies of trace minerals can cause serious problems
Determining Nutritional Needs • Recommended Dietary Allowances (RDAs) • Adequate Intake • Daily Values • Recommended Daily Intakes (DRIs) • Daily Reference Values (DRV) • Reading food labels can help determine needs
Reading a Food Label Figure 9.6
ABC News: Nutrition • Discussion Questions • Discuss whether you think manufacturers are intentionally misleading consumers regarding serving size listings on their products. Why or why not? • What kinds of standards for food labeling would you recommend to manufacturers? Play Video | Nutrition
The New MyPyramid Food Guide • Replaced the food guide pyramid to account for varied nutritional needs throughout the U.S. population • Emphasizes • Personalization • www.mypyramid.gov • Gradual improvement • Physical activity • Variety • Moderation • Proportionality
The MyPyramid Plan Figure 9.7
Serving Size Card Figure 9.8
Nutritional Needs for Different Groups Figure 9.9
Vegetarianism: Eating for Health • MyPyramid Plan adaptable for a vegetarian diet • Types of vegetarian diets • Vegan • Lacto-vegetarian • Ovo-vegetarian • Lacto-ovo-vegetarian • Pesco-vegetarian • Semivegetarian
Vegetarianism: Eating for Health • Reasons why 5-15% of the population are vegetarians • Aesthetic • Animal rights • Economic • Personal • Health • Cultural • Religious
The Medicinal Value of Food • Compelling evidence that diet may be as effective as drugs • Functional Foods • Antioxidants • Carotenoids
The Medicinal Value of Food • Folate • Form of vitamin B • Folate fortification 1998 • Neural tube defects • Heart disease • Probiotics • Found in fermented milk products
Supplements • Dietary supplements • Products taken by mouth to supplement existing diets • Includes vitamins, minerals, herbs • FDA does not evaluate supplements prior to their marketing; companies responsible for own monitoring • If in doubt about supplements, simply eat from the major food groups • A multivitamin added to a balanced diet will generally do more good than harm
Gender and Nutrition • Men and women have different needs • Women have cyclical changes • Men have more lean tissue (burn more)
Changing the “Meat-and-Potatoes” Diet • Reasons to change • Heavy red meat eaters are five times more likely to get colon cancer, and twice as likely to develop prostate cancer • Fruits and vegetables reduce stroke risk as well as risk for oral, bladder, and pancreatic cancers • Cancer of the esophagus is one of the fastest rising malignancies in the U.S., among white men in particular
Improved Eating for the College Student • Variety of challenges for healthy eating • Eating breakfast and lunch vital for keeping energy up throughout the day • Make lunch and bring it with you, including healthy snacks • Will keep you from buying less healthy food on the run • Limit sugar-heavy beverages and fried products
Improved Eating for the College Student • Nutritional eating on a budget can be done • Buy vegetables locally and in season • Use coupons or shop at discount or bulk food stores • Your city or county health department may have suggestions if you don’t have the funds to eat properly
Food Safety: A Growing Concern • Food-borne illness • Affects millions of people each year • Responsible for 5,000 deaths a year • Signs • Cramping • Nausea • Vomiting • Diarrhea
Food Safety: A Growing Concern • Key factors why food-borne illness has increased • Globalization of food supply • Inadvertent introduction of pathogens to new geographic regions • Exposure to unfamiliar food-borne hazards • Changes in microbial populations • Increases susceptibility of varying populations • Insufficient education about food safety