1. Chapter 2 Guidelines for Designing a Healthy Diet

2. Chapter Outline Diet planning principles (2.1)
Evaluating nutritional health (2.2, 2.3)
Levels of nutritional status
Deficiencies
Food Guides – skip pages 53-59
Using My Plate (2.4 & Myplate.gov)
Nutritional recommendations – DRI (2.5)
Science behind nutritional research (2.6)
Food labels (2.7)
Health Claims

3. Planning a Healthy Diet
Adequate Diet is a diet that provides enough energy to maintain a healthy diet and provides nutrients needed for optimal health
General philosophy for an adequate diet….Eat a variety of foods in moderation.

4. Diet-Planning Principles (5)
Balance
Variety
Nutrient density
Energy density – Kcal control
Moderation

5. Diet-Planning Principles
Balance
Diet that provides enough, but not too much of each type of food
Don’t want overeating of one food type to “crowd” out intake of other nutrients….

6. Diet-Planning Principles
Variety - Diet that includes a wide selection of foods within each food group
Eat a variety of fruits, not just oranges
Why?
Variety within the fruit and vegetable groups has the added bonus of increasing the variety of phytochemicals in your diet.

7. Phytochemicals
Phytochemicals – substances in plants that may contribute to health
Examples – see page 12
Functional Foods – foods that provide health benefits beyond those of the known nutrients

8. Diet-Planning Principles
Nutrient Density
Select foods that provide the most nutrients for the least number of calories (nutrient dense foods)
Skim milk versus soda (page 40)
Foods with few nutrients and many calories are sources of empty calories.

9. Diet-Planning Principles
Energy Density - Kcal Control
Foods with low-energy density have low kcal per gram, page 41
Can eat “a lot” without many calories
Select foods with low energy density for an intake that meets nutritional needs without excess kcal intake

10. Energy Density Measure of the kcal per gram of food
_______ has the highest energy density of the 3 energy-yielding nutrients.
Foods with a high energy density
provide more kcal per gram than low density foods.

11. Energy Density

12. Diet-Planning Principles
Moderation
Eat moderate (small) portion sizes
Moderate your intake of foods high in:
Added sugars
Salt
Saturated and trans fats
Cholesterol
Alcohol

13. Diet-Planning Principles (5)
Balance
Variety
Nutrient density
Energy density – Kcal control
Moderation

14. Levels of Nutritional Status
Desirable/Ideal nutrition
Intake is sufficient to meet daily needs and to keep nutritional stores full while maintaining a healthy body weight

15. Levels of Nutritional Status
Borderline nutrition – a subset of undernutrition in text
Intake is not sufficient to meet daily needs
Drawing upon your stores
Body is not prepared to handle times of stress
Illness, pregnancy…
May slows growth and development of fetus and growing child

16. Levels of Nutritional Status
Undernutrition
Intake does not meet daily caloric and nutrient needs and nutrient reserves are empty for some/all nutrients
There is a decline in body functions due to the lack of nutrients
Can be life threatening
Medical intervention required

17. Nutritional Deficiencies
Covert vs. overt deficiency
Covert or sub-clinical – deficiency may be detected by lab tests, but not outward signs of the deficiency
Overt or clinical symptoms– outward signs of the deficiency

18. Nutritional Deficiencies
Primary vs. secondary deficiency
Primary – inadequate intake of the nutrient
Secondary – body doesn’t absorb adequate amounts, excretes too much….
Body “mishandles” the nutrient
Diet history helps distinguish between these

19. Under-nourished Populations at increased risk:
anyone living in poverty
especially infants, children, pregnant women, elderly
elderly in general, including those living in nursing homes
pregnant teens
drug and alcohol addicts
individuals with eating disorders
anyone with prolonged illness, including hospital patients

20. Overnutrition Over-nutrition – 2 aspects
excessive caloric intake that leads to obesity
Increase risk of obesity related diseases
heart disease, diabetes….
overuse of vitamin supplements that leads to toxicity

21. Malnourished Comment on a commonly used term….
The term malnourished is most commonly used in reference to chronic under-nutrition
It can also be used in reference to anyone with chronic poor nutrition that results in failing health

22. Evaluating Nutritional Status
Background - Personal History
SES
Social history - living situation, marital status
Personal and family health history
Medications, supplements taken
Educational level…..
Anthropometric data (A)
Height and weight
Waist circumference
% body fat

23. Evaluating Nutritional Status
3. Biochemical Assessment (B)
Laboratory tests, eg
Cholesterol level
Iron, potassium, vitamin D levels
Liver enzyme function
4. Clinical Assessment (C)
Physical exam
Hair, skin, eyes, tongue…
Blood pressure

24. Evaluating Nutritional Status
5. Diet History (D)
Typical foods eaten
Food journal
6. Environmental Assessment (E) – part of background/personal history

25. The abc’s of evaluating nutritional status
Anthropometric data
Biochemical tests
Clinical assessment
Dietary intake
Environmental status
Living conditions….from background information see page 43

27. Diet Planning Guides Food Group Plans Food Group Plans include:
Foods within each food group provide similar nutrients and are from similar food sources
Plan recommends the amount of food to be eaten in each food group.
Food Group Plans include:
USDA Food Guide (Pyramid/MyPlate)
DASH diet

28. Old Food Pyramid
See board for updates!

29. 2005 USDA Food Guide -MyPyramid

30. Food Pyramid  My Plate (6/11)

31. USDA Food Guide Assigns foods to 5 (6?) major food groups
Recommends daily intake levels from each group
Recommendations vary depending on caloric needs
Recommends weekly intake goals for several food groups.

32. My Plate - Grains 5-8 ounces bread, pasta, cereal, rice
Half should be from whole grains
1 slice of bread
½ English muffin, bun
½ cup cooked rice, pasta, cereal
1 ounce dry cereal

34. Fruits and Vegetables
Make half your plate fruits and vegetable!

35. My Plate - Vegetables 2-3 cups vegetables
Choose a variety from all 5 subgroups weekly (see next slide)
1 cup cooked or raw vegetables
2 cups leafy vegetables (raw)
¾ cup vegetable juice

36. Eat a Variety of Vegetables
Vegetable subgroups
Dark green – broccoli and dark greens
Red, orange, yellow – carrots, peppers, winter squash, sweet potatoes
Legumes – black beans, kidney beans, soybeans, navy beans….
Starchy – corn, peas, potatoes, lima beans
Other – green beans, brussel sprouts, mushrooms, tomatoes, vegetable juices…

37. My Plate - Fruits 1 – 1 ½ cups of fruit Consume a variety of fruits
No more than 1/3 from juices
1 orange, apple, banana (all medium size)
½ grapefruit
½ cup canned fruit or berries
3/4 cup fruit juice

38. My Plate - Dairy 3 cups/serving dairy Choose low/no-fat options
1 cup milk
80 kcal, skim
100 kcal, 1% milk
159 kcal, whole milk
1 cup yogurt
1 ½ ounces cheese (170 kcal for cheddar)
Calcium enriched soy milk

39. Food Plate - Proteins 5-6 ½ ounces meat and meat alternatives
Meat, poultry, fish, eggs, seeds, nuts, legumes – ounce equivalents
½ ounce nuts
1 egg
1/4 cup cooked legumes = 1 ounce
1 tablespoon pb

40. My Plate - Oils Oils – 5-7 teaspoons per day Olive oil Canola oil
Corn oil
Vegetable oil

41. My Plate – Empty Calories
Fats and sugars – eat sparingly
Butter, margarine
Cream, sour cream, cream cheese, mayo.
Candy, soda, sugar, honey….
Sports drinks, energy drinks

42. My Plate
Strengths:
Drawbacks:

43. Putting the Plan into Action
Copyright 2005 Wadsworth Group, a division of Thomson Learning

44. MyPlate Physical Activity
Adults should do at least 2 hours and 30 minutes each week of aerobic physical activity at a moderate level OR
1 hour and 15 minutes each week of aerobic physical activity at a vigorous level.

45. Science Of Nutrition
Nutritional recommendations are based on scientific research.
Recommendations attempt to define adequate intake.

46. Dietary Recommendations
Dietary Reference Intakes (DRI)
EAR - Estimated Average Requirements
RDA – Recommended Dietary Allowances
AI – Adequate Intake
UL – Tolerable Upper Intake Levels
All based on nutritional research.

47. EAR and RDA Estimated Average Requirements
Intake amount that appears to meet the needs of 50% of the population
Age, gender, “condition” based
Set after review of many research studies
Recommended Dietary Allowances
RDA is set to meet the needs of 98% of the population (without reaching toxic levels)

48. DRI

49. AI Adequate Intake (AI)
AI = average amount of the nutrient that a group of healthy people consume
AI is set when there isn’t enough research to set an estimated average requirement (EAR) or RDA
Examples: Vitamin D, water, fiber

50. UL Tolerable Upper Intake Level (UL)
Maximum daily amount of nutrient that appears safe for most healthy people
Intake above the UL is associated with toxicity symptoms
Most often see with overuse of supplements or intake of many fortified foods

51. DRI

52. Other Recommendations
Estimated Energy Requirements (EER)
Caloric intake that will maintain energy balance in a healthy person
Values given are for “reference” male and female who is fairly active
Values are not very useful for individuals!

53. Energy – Why not set an RDA?

54. Other Recommendations
Acceptable Macronutrient Distribution Range
or, recommended intake of energy yielding nutrients
45-65% of caloric intake from carbohydrate
20-35% of caloric intake from fat
10-35% of caloric intake from protein

55. The Science of Nutrition
One of the newest sciences
New branch is nutritional genomics
Study of the interaction of nutrients with DNA/genes and how those genes impact health
Like all sciences, nutrition is based on scientific research

57. Scientific Method Observations  Questions Hypotheses  Predictions
Test hypotheses/predictions
Analyze data and draw conclusions
Share results
Page 64

58. Observations and Questions
Make observations about diet and health. These observations lead to questions
For example:
The incidence of breast cancer is much lower in Japan than in the U.S.
Diet in Japan is rich in…..while in U.S. diet is rich in ……
Question?:

59. Develop Hypotheses and Make Predictions
Hypothesis – tentative explanation of the observations or answer to the question
Make prediction – If the hypothesis is true what else is true?

60. Experiments Conduct experiments to test the predictions
Easier said than done when people are involved!
We’ll consider research designs later/soon.

61. One Experimental Design
When possible, randomly assign subjects to either a control of experimental group
Goal is for two groups to be as similar to each other as possible
Control Group – either no change to diet or given a placebo
Experimental group – diet changed or given a supplement

62. Experimental Design
Compare the health/lab values of the two groups before and after the diet change.
Example – DASH diet study

63. Analyze results… Analyze results
Draw conclusions about the validity of the hypothesis
Test alternate hypotheses
Share findings
Publish in nutritional journals
Present findings at conferences

64. Common Research Designs
Epidemiological study (observe)
Cross-sectional
Longitudinal
Case-control study
Experimental (intervene)
Animal studies
Human clinical trials
Double blind study
Lab studies

65. The Science of Nutrition
1. Epidemiological studies
Study of populations
Look for correlations between dietary practices and health

66. Epidemiological Studies
Cross-sectional - look for correlations between diet and health at a point in time
Longitudinal Studies - Follow a group of people (a cohort) over a period of time
Look for differences in diet that might account for the differences in health

67. Epidemiological Studies
Case-control study – compare the diet of individuals with a condition to that of healthy individuals
Again, do not change their diet…..just observe it.
Go to page 65 if not already there…

68. Human Experimental Studies
Often called a Clinical Study
Randomly assign like people to either the experimental or control group
Alter the diet of experimental group as compared to a control group
Compare incidence of disease/lab values/ performance …. of two groups

69. Types of Clinical Trials
Blind experiments
Subjects do not know which group they are in
Double blind experiments
Neither subjects nor the researchers know which group the subjects are in until after the experiment is over
Goal is to avoid bias in the reporting/recording of the data.

70. Experimental Studies Animal Studies
Controlled studies in lab setting using animals
Alter diet of experimental group
Compare health/lab values of control and experimental groups
Benefits? ….
Drawbacks? ……

71. Experimental Studies Lab-Based Studies Also called in vitro studies
Examine impact of a substance on living tissue in a “test tube”

73. The Science of Nutrition
Size matters
Good studies have relatively large sample sizes
Preliminary studies have smaller sample sizes
Peer review matters
Information in peer- reviewed research journals is much more credible than that in popular magazines, TV, Internet

74. Food Labels Ingredient list Serving size
Listed by weight in product (most to least)
Serving size
Set by gov’t for each food type
Not the same as the MyPlate serving

75. Food Labels Nutritional content compared to Daily Values
Daily Values are estimates of the needs of 2000 kcal per day consumer
Not the same as RDA – why?

76. Food Labels Specific nutrition facts Kcal/serving Kcal from fat
Total fat, grams and % Daily Value (DV)
Grams saturated fat, % DV
Grams trans fats – added 2006
Cholesterol (mg and % DV)
Sodium (mg and % DV)

77. Food Labels Nutrition Facts, cont’d Total grams carbohydrate
Grams sugar
Grams and % DV: fiber
Grams protein
% DV:
Vitamin A
Vitamin C
Iron
Calcium

79. Food Labels
“Health” claims allowed on food labels are regulated by the FDA
Law changed in 2003 to allow more health claims
Much more confusing now
Now health claims with limited evidence can now be put on labels with a “disclaimer”/explanation.
Pages 68/69

81. Food Labels

82. Food Labels “Structure-function” claims do not require FDA approval
Cannot mention a disease or symptom
Limited regulation of claims on dietary supplements (since 1994)

84. Food Labels “May reduce the risk of heart disease.”
A “health” claim
Regulated and needs FDA approval.
“Promotes a healthy heart.”
A “structure-function” claim
No FDA approval or proof needed to make

85. Other Recommendations
Other countries and international organizations set their own nutritional recommendations
e.g. World Health Organization (WHO)