1. An Overview of Nutrition Lancelot McLean, PhD lmclean@llu.edu

2. Nutrient Composition of the Body

3. The Nutrients Water Hydrogen & oxygen Inorganic Minerals
Simplest nutrient
Vitamins
Organic
Carbohydrates
Organic
Proteins
Contains nitrogen
Lipids (fats) 3

4. The Nutrients

5. Average energy available from the major food components
Energy content of Food
Energy content of food is calculated from the heat released by the total combustion of food in a calorimeter.
Expressed in kilocalories (kcal, or Cal)
Fat is the most energy dense
Alcohol is not a nutrient
Average energy available from the major food components
1 kcal (1 food calorie) = 4.2 kilojoules

6. The Vitamins Thirteen organic vitamins
Water-soluble vitamins (B1, B2, B3, B5, B6, B7, B9, B12, C)
Fat-soluble vitamins (A, D, E, K)
Facilitate energy release but do not provide energy of their own
Almost every bodily action requires assistance from vitamins
Vulnerable to destruction by heat, light and chemical agents

7. The Minerals & Water Minerals Do not yield energy
Sixteen essential minerals
Major minerals: Ca, P, K, Na, Cl, Mg, and S
Trace minerals: Fe, I, Zn, Cr, Se, F, Mo, Cu, and Mn
Indestructible
Person may be deficient due to inability of the body to absorb them
Also can be lost during food-refining or during cooking when they leach into the water that is discarded
Water
Medium for nearly all body activities

8. Energy Requirements in Humans
The Estimated Energy Requirement (EER) is the average dietary energy intake predicted to maintain an energy balance in a healthy adult of a defined age, gender, and height whose weight and level of physical activity are consistent with good health
Differences in the genetics, body composition, metabolism, and behavior of individuals make it difficult to accurately predict a persons caloric requirements.
To maintain body weight
Sedentary adults: 30 kcal/kg/day
Moderately active: 35 kcal/kg/day
Very active: 40 kcal/kg/day
Daily calories on food labels is either 2000 or 2500 kcal/day

9. How energy is used in the Body
Resting Metabolic Rate (RMR)
Energy expended in a resting, post absorptive state
Energy required for normal body functions
About 1300 kcal for a 50 kg woman, 1800 kcal for 70 kg man
50 – 70% of daily energy expenditure in sedentary individuals
Formerly Basal Metabolic Rate (BMR)
Thermic Effect of Food
Production of heat during the digestion and absorption of food
Body heat production increases as much as 30% above the resting level
Over a 24 hour period may amount to 5 – 10% of total energy expenditure
Physical Activity
Muscular activity
A sedentary person requires about % more than the resting caloric requirement for energy balance
Highly active person may require 100% or more calories above the RMR

10. How energy is used in the Body

11. Acceptable macronutrient distribution ranges (AMDR)
Defined as a range of intakes for a particular macronutrient that is associated with reduced risk of chronic disease while providing adequate amounts of essential nutrients
For adults
45-65% of their total calories from carbohydrates
20-35% from fat
10-35% from protein

12. Nutrition Assessment – Individual Level
Deficiency or excess over time leads to malnutrition
Undernutrition
Extremely thin
Losing muscle tissue
Prone to infection and disease
Skin rashes
Depression
Hair loss
Bleeding gums
Muscle spasms
Night blindness
Overnutrition
Obesity
Vulnerable to diseases associated with overnutrition such as heart disease and diabetes

13. Diet and Health

14. Nutrition Information & Misinformation
Identifying nutrition experts
The American Dietetic Association (ADA) states that standard nutrition education should be included in the curricula for ALL health care professionals
Physicians & other health-care professionals
Training in nutrition is limited
Registered Dietitian (RD)
Has the educational background necessary to deliver reliable nutrition advice and care
Degree and clinical internship
National exam
Maintain up-to-date knowledge
Dietetic Technician, Registered (DTR)
Assists Registered Dietitian

15. Nutrition Information & Misinformation
8 RED FLAGS

16. Planning a Healthy Diet

17. Principles and Guidelines
Adequacy
Sufficient energy
Adequate nutrients to meet needs of healthy people
Balance
Enough but not too much
kCalorie (energy) control
Energy in = energy out
High nutrient density foods

18. Principles and Guidelines
Nutrient density
Good: The most nutrients for the fewest food energy
- nutrient dense foods
Bad: Low-nutrient density foods (empty kcalorie foods)
Can sometimes be difficult to determine which food is generally more nutrient dense when dealing with multiple nutrients
Moderation
Food selections – Select foods low in fat & added sugars
High fat and sugar provide enjoyment and energy but relatively few nutrients
Promote weight gain when eaten in excess
Variety
Different foods within the same group contain different arrays of nutrients
No food is guaranteed to be free of substances that, in excess, could be harmful
“Variety is the spice of life”. Lack of boredom.

19. Principles and Guidelines
Dietary Guidelines for Americans (Page 38 of Textbook)
Science-based advice
Promote health and reduce chronic diseases
Has 9 areas of recommendation, covering
Diet
Physical activity

20. Diet-Planning Guides USDA (US Department of Agriculture) Food Guide
Recommended daily amounts for each group
Notable nutrients
Serving equivalents
Nutrient density

21. USDA food guide

22. USDA food guide

23. USDA food guide Serving equivalents Vegetarians Ethnic food choices
Fruits, vegetables, milk = cups
Grains and meats = ounces
Vegetarians
Can still use USDA Food Guide
The food groups are similar and the amounts for each serving remain the same
Ethnic food choices
Individuals can sort ethnic foods into their appropriate food groups

24. Health Benefits of Vegetarian Diets
Vegetarian lifestyle factors
Absence of tobacco, drugs, alcohol, and presence of physical activity
Limitations of research to determine the effect of diet alone
Despite limitations research suggests that well-planned vegetarian diets offer sound nutrition and health benefits to adults
Blood pressure
Heart disease
Cancer
Other diseases

25. Am J Clin Nutr. 2009 May;89(5):1607S-1612S. Epub 2009 Mar 25.
Vegetarian diets: what do we know of their effects on common chronic diseases?
Fraser GE.
Source
Department of Epidemiology and Biostatistics, Loma Linda University, Loma Linda, CA, USA.
Erratum in
Am J Clin Nutr Jul;90(1):248.
Abstract
A number of studies have evaluated the health of vegetarians. Others have studied the health effects of foods that are preferred or avoided by vegetarians. The purpose of this review is to look critically at the evidence on the health effects of vegetarian diets and to seek possible explanations where results appear to conflict. There is convincing evidence that vegetarians have lower rates of coronary heart disease, largely explained by low LDL cholesterol, probable lower rates of hypertension and diabetes mellitus, and lower prevalence of obesity. Overall, their cancer rates appear to be moderately lower than others living in the same communities, and life expectancy appears to be greater. However, results for specific cancers are much less convincing and require more study. There is evidence that risk of colorectal cancer is lower in vegetarians and in those who eat less meat; however, results from British vegetarians presently disagree, and this needs explanation. It is probable that using the label "vegetarian" as a dietary category is too broad and that our understanding will be served well by dividing vegetarians into more descriptive subtypes. Although vegetarian diets are healthful and are associated with lower risk of several chronic diseases, different types of vegetarians may not experience the same effects on health.
PMID: [PubMed - indexed for MEDLINE] PMCID: PMC

26. A classification of vegetarian diets that is used in the
Adventist Health Study-2.
A classification of vegetarian diets that is used in the Adventist Health Study-2. Note: Vegans (total vegetarians) eat no red meat, fish, poultry, dairy, and eggs; lactoovovegetarians (LACTO-OVO) eat milk, eggs, or both but no red meat, fish, or poultry; pescovegetarians (PESCO-VEGE) eat fish, milk, and eggs but no red meat and poultry; semivegetarians (SEMI-VEGE) eat red meat, poultry, and fish less than once a week; and nonvegetarians (NON-VEGE) eat red meat, poultry, fish, milk, and eggs more than once a week.
Fraser G E Am J Clin Nutr 2009;89:1607S-1612S
©2009 by American Society for Nutrition

27. BMI2 Diabetes3 Hypertension3
TABLE 1
Mean BMI (in kg/m2) and the prevalence of diabetes and hypertension in different types of vegetarians compared with nonvegetarians in California Seventh-day Adventists: preliminary analyses adjusted for age, sex, and race1
Diet group
BMI2
Diabetes3
Hypertension3
Nonvegetarian
28.26 (28.22, 28.30)
1.00
Semivegetarian
27.00 (26.96, 27.04)
0.72 (0.65, 0.79)
0.77 (0.72, 0.82)
Pescovegetarian
25.73 (25.69, 25.77)
0.49 (0.44, 0.55)
0.62 (0.59, 0.66)
Lactoovo-vegetarian
25.48 (25.44, 25.52)
0.39 (0.36, 0.42)
0.45 (0.44, 0.47)
Vegan
23.13 (23.09, 23.16)
0.22 (0.18, 0.28)
0.25 (0.22, 0.28) P4
0.0001
Fraser G E Am J Clin Nutr 2009;89:1607S-1612S

28. Vegetarian Diet Planning
Most vegetarians easily obtain large quantities of the nutrients that are abundant in plant foods
Carbohydrate, fiber, thiamin, folate, vitamin B6, vitamin C, vitamin A and vitamin E
Some vegetarian diets might lack adequate amounts of
Protein, iron, zinc, calcium, vitamin B12, vitamin D and omega-3 fatty acids
Vegetarian food guides help to overcome this potential problem

30. My Pyramid: Steps to a Healthier You

31. USDA food guide MyPyramid – http://www.mypyramid.gov
Educational tool
Combines USDA Food Guide and Dietary Guidelines
Allows for personal planning
Pyramid shortcomings by critics
Fails to convey enough information to help consumers make informed decisions about diet and health.
Overemphasizes some foods and underemphasizes others, which may be detrimental to health. Whole grains deserve more attention. Red meats should be used sparingly.
Milk products offer no real benefits in preventing osteoporosis

32. Diet-Planning Guides

33. Food Labels