Download Chapter 1 Notes: Food Choices and Human Health

Chapter 1 Notes: Food Choices and Human Health
Introduction
●Nutrition
-the study of how food nourishes the body
-the study of nutrients in food and the body
●Food
-any substance the body can take in and assimilate
-used to enable the body to stay alive and grow
-A source of nutrients
Diet – Foods a person usually eats and drinks
●Nutrients
-Components of food required for the body’s functioning
-Roles:
-provide energy
-building material
-maintenance and repair
-support and growth
-Categories of nutrients
-water
-carbohydrates
-fat
-protein
-vitamins
-minerals
A lifetime of Nourishment
●Optimal food
-food that supports the growth and maintenance of muscle, bones, skin, and sufficient blood
-food should supply sufficient energy, water, carbohydrates, fat, protein, vitamins, and minerals
●Diet can influence the risk of suffering from chronic diseases such as:
-heart disease
-diabetes
-some kinds of cancer
●Besides diet, other factors affect health
-tobacco use, alcohol use, substance abuse, physical activity, sleep, stress, conditions at home or
work
The Human Body and Its Food
●Energy
-The ability to do work
-The energy that fuels the human body comes indirectly from the sun via plants
The Nutrients in Food
●Water – Constantly lost from the body
-Must constantly be replaced
●Energy-yielding nutrients
-Body can use the energy these nutrients contain
-Carbohydrates
-Lipids
-Proteins
-Also provides material that forms the structure and the working parts of the
body
●Minerals
-do not provide energy to the body
-a few serve as parts of body structures
ex: calcium and phosphorus in bone
●Vitamins
-do not provide energy to the body
●Minerals and vitamins
-regulators that assist in all body processes
●Essential nutrients
-nutrients that the body cannot make, or cannot make fast enough, from other raw materials
-nutrients that must be obtained from food
-if not, deficiencies will occur
-include
-water
-a form of carbohydrate
-some lipids
-some parts of proteins
-vitamins
-minerals
●calories
-units of energy
-kilocalorie=kcalorie=calorie
-used to measure energy in food
-amount of heat energy needed to raise the temperature of 1 kilogram of water 1degree C
carbohydrate – 4 cal/gram
fat (lipid) – 9 cal /gram
protein – 4 cal/gram
●Dietary Supplements
-pills, liquids, or powders that contain purified nutrients or other ingredients
-cannot be used in place of food
-food offers more than just the six basic nutrients
Can I live just on supplements?
●Digestive tract is a dynamic system that responds to the food it receives
-including sight, aroma, and taste of food
-when a person is fed through a vein the digestive organs atrophy
-lack of digestive tract stimulation may weaken the body’s defenses against certain infections
●Foods are chemically complex
-in addition to nutrients foods include nonnutrients
-compounds other than the six nutrients present in food that have biological activity in the
body
●nonnutrients include phytochemicals
-nonnutrients compounds in plant-derived foods that have biological activity in the body
-confer color, taste, etc. on foods
-many are though to affect health by reducing disease
How, Exactly, Can I recognize a Nutritious Diet?
●Adequacy
-the dietary characteristic of providing all of the essential nutrients, fiber, and energy is sufficient
amounts to maintain health and body weight
●Balance aka. Proportionality
-the diet characteristic of providing foods of a number of different types in proportion to each
other
-such that foods rich in some nutrients do not crowd out of the diet foods that are rich in
other nutrients
●Calorie Control
-control of energy intake
-a feature of a sound diet plan
●Moderation
-the dietary characteristic of providing constituents within set limits
-nothing in excess
●Variety
-the dietary characteristic of providing a wide selection of food
-the opposite of monotony
Dietary Guidelines
●USDA issues Dietary Guidelines for Americans
-consist of 18 guidelines clustered into 9 groups
●Why be Physically Active?
-reduced risk of cardiovascular diseases
-increased cardiovascular endurance
-increased muscle strength and endurance
-increased flexibility
-reduced risk of some types of cancer
-especially colon and breast cancer
-improve mental outlook and lessened likelihood of depression
-improved mental functioning
-feeling of vigor
-feeling of belonging
-the companionship of sports
-strong self image and belief in one’s abilities
-reduced body fatness, increased lean tissue
-a more youthful appearance, healthy sink, and improved muscle tone
-greater bone density and lessened risk of adult bone loss later in life
-increased independence in the elderly
-sound, beneficial sleep
-faster wound healing
-lessening or elimination of menstrual pain
-improved resistance to infection
Conclusion
●Nutrient Density
-measure of nutrients provided per calorie of food
-tool to help make good nutrition easier
●Foods that offer the most nutrients per calorie are vegetables
-especially nonstarchy vegetables
-these foods are rich in phytochemicals
-these foods are inexpensive but take time to prepare