what is nutrition?
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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. - PowerPoint PPT PresentationTRANSCRIPT
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