what is nutrition?

What is Nutrition?

•The science of food, the nutrients and the substances therein,

•their action, interaction, and balance in relation to health and disease,

•and the process by which the organism ingests, digests, absorbs, transports, utilizes, and excretes food substances.

States of Nutritional Health

Desirable Nutritionnutrients consumed support body functions and stores for times of increased need.

Malnutrition–Undernutritionnutrient intake does not meet minimal needs; can lead to reduced biochemical function and serious long term effects

–Overnutrition*nutrients are consumed in excess of the body needs; can lead to toxicity or obesity

* biggest problem in the US due to excess of saturated fats and salt

atherosclerosis

stroke

hypertension

diabetes

cancer cells

obesity

heart disease

bacteria

virusesstress

fungiparasites

high in fiber and fluid

high in fruit

low in saturated and trans fats

high in whole grains

little or no alcohol

high in vegetables

adequate in nutrients

moderate in calories

*

Nutrition and your Health

Leading Cause of Death in the

U.S.

•4 of top 6 are nutrition-dependent

Nutrition and Your HealthPoor diet is a risk factor for several chronic diseases and ailments

–heart disease–cancer (e.g., colon, breast)–diabetes–stroke–hypertension–Anemia (iron-deficiency)–osteoporosis–cirrhosis of the liver–fetal alcohol syndrome–stunted growth

Poor diets kill 300,000 people/year from these top 3 diseases alone

The Science of Nutrition•Nutrition is true science but a young science

–1897 – first vitamin identified

–1940’s – first protein structure

•It is a complex, interactive science

•Research Design can take many forms:–Epidemiological study

–Case study

–Laboratory study

–Intervention study

Pellegra

Scientific Method

Nutrition, Disease, and Genetics

•nutritional genomics•molecular nutrition•nutrigenomics

New Research Fields:

Agouti Mice

How Aware are You of your Nutritional Health?

•overall population is getting fatter

•probably due to an increasingly sedentary lifestyle,

•poorer diets,

•and a busier work schedule

World Malnutrition

• Undernutrition: ~800 million people

• Nutrient Deficiency: 2-3.5 billion people

• Overnutrition: ~ 1.1 billion

Undernutrition

From United Nations (2004)

Undernourished Population: 2002-2004

USA Overnutrition numbers

• 2000:

– 64% of people are considered overweight

– 30% of people are considered to be obese

– 1/7 children and teenagers are considered to be overweight

Fig. 9-1, p. 312

Key:

In 2002, 29 states had obesity rates of 20 to 24 percent and rates of 3 more topped 25 percent.

2002

In 1991, only 4 states had obesity rates >15 percent.

1991

≥ 25%

15% to 19%

20% to 24%

10% to 14%

<10%

No data available

Obesity Rates across the US

Obesity Rates

http://www.cdc.gov/obesity/data/trends.html

Obesity across the World

More people in the developing world are now overweight than hungry

The Problem with Globalization

• Globalization: as the middle class of a third world or developing country expands the opportunity to purchase a wider range of products increases:– Grocery stores– Electronic goods– Automobiles

• Globalization increases the availability of unhealthy food sources– Sweetened beverages– Vegetable oils– Animal source foods

• Globalization increases sedentary behavior– Increase television viewing– Decrease physical exercise

The Changes in Mexico• 1989:

– <10% of the population is considered to be overweight

– Obesity/Type II Diabetes were not health issues

– Hunger and poverty were the main issues of concern

• 2006:– 77% of males are considered to be overweight or obese

– 66% of females are considered to be overweight or obese

– 1/7 have Type II Diabetes and it is spreading

The Problemwith EatingAway from

Home

Super-Size Me?

More Calories are Available

More Caloric Sweeteners are Available

More Sugary Soft Drinks are Available

Why Should You Eat?

We eat to get Nutrients.

Nutrients are the nourishing substances we must obtain from food. These essential substances are vital for growth and maintenance from infancy to adulthood.

The minimum diet for healthy growth, development, and maintenance MUST contain about 45 essential nutrients.

Function of Nutrients

•Energy Providers

•Growth and Development Providers

•Body Processes Regulators

Energy Providing Nutrients

Food Energy is measured in calories (kilocalorie, Calorie): The amount of heat energy necessary to raise the temperature of a liter

(1 kilogram) of water 1 degree Celsius.

Metabolic Rate (MR): The overall rate at which nutrients are broken down to produce energy for ATP and heat

Basal Metabolic Rate (bMR): The rate at which a quiet, resting, fasting body breaks down nutrients to liberate energy. The thyroid hormone is the main regulator of bMR

Table 1-3, p. 6

•Energy Producing Nutrients:

•Carbohydrates

•Fats/Lipids

•Proteins

Growth and Development NutrientsBody Process Regulator Nutrients

•Vitamins

•Minerals

•Water

•Proteins (some functions)

•Fiber (from carbohydrates)

Why Do We Eat What We Do?

Body Image

Nutritious Diet Characteristics

•Adequacy–Foods provide enough of each essential nutrient, fiber, and energy

•Balance–All food groups are represented; one is not overrepresented

•Calorie Control–Food provides enough energy to maintain weight

•Moderation–There is no excess nor unwanted food groups

•Variety–Foods differ from one day to the next

Dietary Reference Intakes (DRI)Represent up-to-date optimal, and safe nutrient intakes

for healthy people in the US and Canada

They are based on scientific investigation

DRI Committee Goals are to:

1. Set Recommended Intake Values (RDA, AI)

2. Facilitate Nutrition Research and Policy (EAR)

3. Establish Safety Guidelines (UL)

4. Prevent Chronic Diseases (AMDR)

Nutrient Standards

Daily Values

Standards used only on food labels to enable customers to compare the nutrient values among foods

They reflect the needs of an average person – someone eating 2000-2500 calories/day

Are much less useful as nutrient intake goals for individuals

1992 Nutritional Requirements

The New 2005 MyPyramid

Process to replace the 1992 model was secret

According to USDA staff:•Keep physically active•Eat in moderation•Make personalized food choices•Eat a variety of foods in the recommended number of servings•Pursue gradual dietary improvement

No more food hierarchies

Influence of food lobbies is apparent

What’s Your Excuse?

Most OftenKnowledge

is Key

Fig. 1-5a, p. 16

2005 US Dietary Guidelines

Fig. 1-5b, p. 16

2005 US Dietary Guidelines

Fig. 1-5c, p. 16

2005 US Dietary Guidelines

Fig. 1-5d, p. 16

2005 US Dietary Guidelines

Fig. 1-5e, p. 16

2005 US Dietary Guidelines

Fig. 1-5f, p. 16

2005 US Dietary Guidelines

Fig. 1-5g, p. 16

2005 US Dietary Guidelines

Fig. 1-5h, p. 16

2005 US Dietary Guidelines

U.S.Nutrition

Objectives 2010