Kin 110 Lecture 2

Chapter 2

Tools for Diet Design

Chapter 3

Human Body

Overview of Lecture 2

• Chapter 2• Definition of Healthy diet

• Food Guide and its uses

• Dietary Guidelines

• Recommended Nutrient Intakes

• Food Labeling

• Nutrient Density and the Exchange System

Chapter 2 Tools for Diet Design

• What do we need to eat to avoid diet related disease?

• A variety of foods balanced by a moderate intake of each food

• variety for all nutrients

• focus on main food groups

• stay physically active

• VARIETY, BALANCE and MODERATION

Variety

• Choose a number of different foods within any given food group

• not the same thing “day after day…”

• WHY ?

Balance

• Select from 5 food groups– four in Canada– Dairy– Vegetable / Fruit– Grains– Meats and Alternates

• fats, oils and sweets can be added for flavour and nutrients

Moderation

• Plan your day in order to juggle nutrient sources

• balance between types of foods• morning vs. evening and within

meal

• moderation of high fat and salt

• Without adopting basics of variety, balance and moderation you risk nutrition related disease

Nutritional Status

• Overall body health is determined by the sum of its nutritional status for each nutrient

• Components Include

• Anthropometry

• Biochemical measurement

• Clinical Examination

• Dietary History

Nutritional Categories

• Desirable Nutrition

• Intake supports body functions

Under Nutrition

• Nutrient intake does not meet body needs

• body enters state in which it can not function appropriately

• body stores can make up for short term, but become depleted

• serious problems can arise over longterm

Over Nutrition

• Prolonged over consumption of more than the body needs

• long term can lead to toxic build up and serious disease

• most common is excess energy intake– excess weight leads to serious

disease

Limits of Nutritional Assessment

• Can be a very long time between the onset of poor nutritional health and the first clinical evidence

• Often too late

• Calcium deficiency - low bone density, osteoporosis later in life ( 30 to 50 years).

• High Cholesterol - builds up in circulatory system, heart disease later in life.

Food Guide

• Rainbow in Canada, Pyramid in USA ( see appendix B)

• Nutritionists have always worked to put the science of nutrition into practical terms that could be useful to everyone

• Goal of this class is to become very familiar with the recommendations and the fundamentals that create the guidelines

Food Guide

• Estimates are based on 1200-1400 kcal intake (minimum)

• Expect an increase in caloric intake to meet energy needs

• Recent changes have increased fruit, vegetable, bread and cereal contributions to provide more calories and moderate fat

• oils and sweets used to supplement energy needs, not to replace other foods

Four Groups

• Group• Grain Products

• Vegetables and Fruit

• Milk Products

• Meat and Alternatives

• Servings• 5 - 12

• 5 - 10

• 2 - 4• Youth, and

pregnant women 3 - 4

• 2 - 3

Summary (Appendix B)• Enjoy a variety of foods

• Emphasize cereals, breads, other grain products, vegetables and fruits

• Choose low-fat dairy products, lean meats, and foods prepared with little or no fat

• Achieve and maintain a healthful body by enjoying regular physical activity and healthful eating

• limit salt, alcohol and caffeine

Menu Planning

• Utilizing the food guide as a tool

• emphasize variety as no one food is essential nor does one provide all the necessary nutrients

• Each member of food group contributes slightly different nutrients (appendix A)

Recommendations for Choices

• Low fat items from milk group

• vegetables high in protein, minerals and fiber (lentils)

• vegetables rich in Vitamin A (dark green) and fruits rich in vitamin C (oranges)

• Choose whole grain breads, cereals and pastas

• refining flour eliminates most nutrients

Sample Daily Diet

• See Table 2 - 6

• meets all requirements for 1600 - 1800 kcal

• modify for greater caloric expenditure

• if less caloric expenditure, increase physical activity

Evaluating Diet

• Most in US failed to meet theses guidelines

• Very low on Fruit and Vegetables, high on sweets, fats and oils

Dietary Guidelines

• Different method for Menu Planning

• KNOW THE DIFFERENCES AND APPLICATIONS

• Food guide designed to have nutrients met

• Main dietary problems are associated with over consumption of energy, Fat, cholesterol, alcohol and salt

• Also, under consumption of calcium, iron, B vitamins, Zinc and fiber

Dietary Guidelines• Dietary guidelines established

in light of these disease concerns

• refer to intake over a day or a week

• 1. Eat a variety of foods

• 2. Balance intake with activity• 30 min of moderate activity a day

• low fat options and nutritious snacks

• high risk with abdominal fat

• slow controlled weight loss

• habit forming changes

Dietary Guidelines

• 3. Emphasize grains, fruits and vegetables (nutrients and fiber)

• 4. Low fat, saturated fat and cholesterol (low fat options, animal products= saturated fat and cholesterol)

• 5. Moderate sugar intake

• 6. Moderate salt (sodium)

• 7. Moderate alcohol• BP, stroke, heart disease, cancer,

……

• two or fewer servings

Recommended Nutrient Intake (RNI)

• Corresponds to RDA (Recommended Dietary Allowance in US)

• Recommended intakes of nutrients that meet the needs of almost all healthy people of similar age and gender

• Used for

• large group meal planning over 3 - 7 days

• schools, hospitals, dormitories

• developing education programs and food labeling standards

• developing new foods (astronauts)

• evaluating diet survey data

RNI

• Developed by :

• estimating what average people require and individual variation

• increasing this by 30-50 % to cover all population

• increasing again to cover losses with cooking and specific needs

• incorporation of scientific judgment to create estimates without available data

RDA

• You should not expect a benefit from eating in excess of RDA

• Revised every four years

• recently focused on presentation and refinement of recommendations for age groupings

• considerations of new research such as the antioxidant effects of Vitamin C

Daily Values

• Recommendations based on daily requirements versus weekly (RNI/RDA)

• used for food labeling as they are more generic general estimates for the whole population

• Reference Daily Intakes (RDI)

• Daily Reference Values (DRV)

Nutrient Density

• Used to assess nutritional quality of individual foods

• comparison of its vitamin or mineral content to its energy provision. Higher the better.

• Fig 2 - 3, p 58

• avoid empty calorie foods.

The Human Body :A Nutrition Perspective

• Various body systems are used to aid in digestion and absorption of food products

• Digestion - breakdown of food substances

• Absorption - transport of food substances into circulatory or lymph system within body

Organization

• Cell - basic building blocks of life, each performing a specialized job, determined by selective expression of DNA

• Tissue - collection of cells designed for specific function

• Organs - groups of tissues designed to perform specific function eg. Heart

• Organism - comprised of organs acting in a coordinated manner to support life

Circulatory System

• Fig. 3-3, p 79

Regulatory (Control) System

• Hormonal and Nervous systems

• hormone - compound with specific site of synthesis and release into bloodstream

• eg. Insulin, gastrin

• nervous system regulates release of acids and intestinal motility, food acquisition, preparation, choice...

Anatomy and Physiology of Digestion

• Gastrointestinal Tract (GI) - site of digestion and absorption

• hollow tube, within which food moves and mixes with digestive acids and enzymes, facilitating breakdown for absorption

• large surface area to facilitate absorption

• movement regulated by sphincters between major sections, allows full preparation

Anatomy of GI

• Fig. 3-4, p 81

• Secretions – Table 3-2, p 80

Digestive Process

• Enzyme Fig 3-7, facilitate one specific reaction repeatedly.

• Different enzymes in different sections of the GI

• Stomach• protein digestion, acid and enzymes

• stomach protected by mucous layer

• Small Intestine• Chyme - mixture of stomach

secretions and food

• entry of chyme into SI slow

• triggers release of bicarbonate and enzymes

Absorption

• Fig 3-9, p 88

• Occurs mainly in SI, 95 % of what it receives

• massive surface area, due to folding and finger like villi

• passive absorption - natural movement from high to low concentration (fats, water)

• active absorption - uses carrier and energy (glucose)

• facilitated absorption - uses carrier without energy