Nutrition: Class Content, Student Questions

1. Nutrition: Class Content, Student Questions Fall 2011

2. Nutrients • Nutrients are substances the body needs to live • Humans need six nutrients • Three contain energy (calories) • Three do not contain energy

3. Energy-Containing Nutrients • Carbohydrates • 4 calories per gram • Protein • 4 calories per gram • Fat • 9 calories per gram Image source: public domain

4. Nutrients Without Energy • Vitamins • Organic substances found in plant and animal sources • A, C, D, E, K, & B vitamins (8 of them) • Minerals • Inorganic substances found in many of the body’s structures (teeth, bones, muscles, blood cells, etc) • Examples: calcium, sodium, iron, chromium, potassium

5. Student Question: Do we need all vitamins? A combination? • A: We need all vitamins. What one person needs, however, will differ from another person based on their dietary behaviors. • Example: person who consumes many fruits & vegetables vs “fast food” eater • Example: a person with nutrient absorption issues may need larger doses than average individual

6. Student Question: Do we need all vitamins? A combination? • Common dietary needs are those vitamins found in fruits & vegetables since many of us do not consume enough • Recommendations: • RDA = Recommended Dietary Allowances • AI = Adequate Intake, if no RDA value set • UL = Upper Limit (highest intake without negative side effects)

7. Student Question: What kinds of fruits & vegetables are most beneficial? • Generally, brightly-colored produce • Vitamins • Minerals • Antioxidants • Variety • Green, leafy vegetables • Bright berries • Tomatoes • Sweet potatoes Photo: Scott Bauer, public domain

8. Student Question: What are the nutritional differences in fruits and vegetables? • Both have nutrients • Generally, vegetables are favored over fruits • Sugar content in fruits • Fructose • Too much = fat storage • Slower absorption rate

9. Student Question: What are the nutritional differences in fruits and vegetables? • Both have nutrients • Generally, vegetables are favored over fruits • Sugar content in fruits • Fructose • Too much = fat storage • Slower absorption rate

10. Student Question: Is a vegetarian diet healthy? • Vegetarian diets can be “healthy” or “unhealthy” • Whole foods: grains, vegetables, fruits, herbs • Fried tofu, mashed potatoes with butter, mac and cheese, candy

11. Student Question: What foods are low-calorie but also filling? • Carbohydrate-based foods are usually digested more quickly, resulting in hunger • Since the body needs carb as its primary energy source, cutting isn’t terribly helpful • Complex carbohydrates take longer to digest than simple carbohydrates • Brown (instead of white) rice

12. Student Question: What foods are low-calorie but also filling? • Foods higher in fiber tend to take longer to digest • Whole grains (barley, bran flakes, oatmeal) • Nuts & seeds (almonds, flax seeds, pistachios) • Fruit (raspberries, pear, strawberries, prunes) • Legumes (lentils, black beans, split peas) • Vegetables (peas, greens, corn, artichoke)

13. Student Question: What foods are low-calorie but also filling? • Water-based foods: soups/broths • Leafy green vegetables • Including protein and healthy fats with carbohydrate at meals can slow digestion • Eggs • Fish • Chicken • Tofu • Almond butter/peanut butter • Avocado

14. Student Question: What Harms Might Vitamins Cause the Body? • WebMD shows RDA or AI, and UL values for vitamins and minerals • Dangers are usually associated with megadoses • Besthealth

15. Student Question: What food chemicals should we look out for? • Challenge: People have varying sensitivities • Challenge: Often, the issue is accumulation rather than one dose at a given time • Challenge: Combinations of chemicals • Challenge: chemicals used for a variety of attractive purposes • Challenge: some chemicals are naturally occurring (estrogenic foods)

16. Student Question: What food chemicals should we look out for? • Challenge: Chemicals used for a variety of purposes attractive to consumer • Preservatives • Sweeteners, flavorings • Fat replacers • Emulsifiers, thickeners • Color additives • List at FDA

17. Student Question: What food chemicals should we look out for? • Guideline: the more processed the food, the more chemicals present • Guideline: shopping around the perimeter of a grocery store usually the healthiest approach

18. Student Question: What food chemicals should we look out for? • Per Center for Science in the Public Interest • Sodium nitrite • Found in meat salty, processed meat products • World Cancer Research Fund, May 2011: processed meats too dangerous for human consumption (totalhealthbreakthroughs.com) • Saccharin, aspartame, Acesulfame-K • Beverages, snack foods, dairy products, gums, soups, snacks • Increased cancer risk

19. Student Question: What food chemicals should we look out for? • Caffeine • Addictive • Stimulant properties • Olestra • Fat substitute in snack chips • Digestive problems • Reduce absorption of some fat-soluble vitamins • Food dyes • Blue 2, Green 3, Orange B, Red 3, Yellow 5, et. Al. • Candy, baked goods, beverages

20. Student Question: What food chemicals should we look out for? • High fructose corn syrup • Beverages, cereals, candy, cookies, condiments • Increases sweetness of food products • Consumers not consuming less sugar • Connection to corn allergies? • Metabolic problems? (insulin resistance) • Bisphenol A in cans, plastics (cancer, reproductive health, CV disease)