Chapter 1 - Science of Nutrition Flashcards
Classes of Nutrients
- Carbohydrates
- Lipids(fats and oils)
- Proteins
- Vitamins
- Minerals
- Water
Nutrition
the science of food
- The nutrients and substances therein - Their action, interaction and balance in relation to health and disease - The process by which the organism ingests, digests, absorbs, transports, utilizes and excretes food substances
Nutrients
substances essential for health that the body cannot make or it can only make in small insufficient quantities
- Provide energy, materials for building body parts and factors needed to regulate chemical processes in the body
Characteristics of Nutrients
- Have a specific biological function
- Cause a decline in human biological function if removed from the diet
- Restore normal human biological functions that was impaired by its absence when returned to diet before permanent change
- Cause a decline in human biological function if removed from the diet
Categories of Nutrients
- Those that provide energy(in kcal)
- Those that enable growth and development
- Those that regulate body processes
- Those that enable growth and development
Macronutrients
nutrients needed in gram quantities in our diets
- E.g. proteins, carbs and fats
- Textbook includes water
Micronutrients
nutrients needed in milligram or microgram quantities in a diet
- Vitamins and minerals
Carbohydrates
- Composed of elements such as carbon, hydrogen and oxygen
- main source of fuel for cells- Two types of carbs:
○ Complex: sugars which chemically bond to form large polysaccharides like starch or glycogen
○ Simple: small carbohydrate structures like sugars - Yields 4 calories per gram
- Two types of carbs:
Lipids
- made up of carbon, hydrogen and oxygen
- Lipids yield 9 calories per gram
- lipids are a triglyceride which are the major form of energy storage in the body
- Composed of 3 fatty acid chains attached to a glycerol molecule
○ Either saturated(solid at room temp) or unsaturated(liquid at room temp) based on the chemical structure of fatty acid tails
Protein
- Composed of carbon, oxygen and hydrogen but also contain nitrogen
- The main structural component in the body
○ Major parts of bone, muscle, components in blood, cell membranes, enzymes and immune factors - Provide 4 calories per gram of energy to cells but not a primary source of energy
- The main structural component in the body
Vitamins
- Contain elements such as carbon, hydrogen, nitrogen, oxygen, phosphorous, sulfur and others
- Main function is to enable chemical reactions
- Some of which release energy from carbs, lipids and proteins
- Themselves provide no usable energy for the body
2 groups:
- fat soluble
- water soluble
Fat Soluble Vitamins
- A
- D
- E
- K
As a result fat soluble vitamins are more likely to build up in the body and create toxicity
Water Soluble:
- C
- B Vitamins:
○ Thiamin
○ Riboflavin
○ Niacin,
○ B-6
○ Pantothenic Acid
○ Biotin
○ Folate
○ B-12
- B Vitamins:
Water soluble vitamins are more easily destroyed by cooking and easily excreted from the body
Minerals
- Structurally simple inorganic substances which lack carbon atoms bonded to hydrogen atoms in chemical structure
- Because they are elements they cannot be destroyed during cooking
- Can leak into cooking liquid and be discarded if food is drained
- They yield no energy but are required due to playing key roles in functioning nervous, skeletal systems and in water balance
2 groups:
- major
- trace
Major Minerals
needed daily in gram amounts
- Sodium
- Potassium
- Chloride
- Calcium
- Phosphorus
Trace Minerals
needed in amounts of less than 100 mg daily
- Iron
- Zinc
- Copper
- Selenium
Water
- An inorganic molecule which is needed in the largest quantity
Function of Water in our body:
- Acts as a solvent and lubricant
- transports nutrients to cells
- Helps regulate body temperatures
Phytochemicals
physiologically active compounds in plant components such as fruits, vegetables, legumes and whole grains may provide health benefits
zoochemical
physiologically active compounds found in foods of animals that may provide health benefits
Functional foods
foods rich phytochemicals and zoochemicals which provide health benefits beyond those supplied by traditional nutrients
- May decrease disease risk and/or promote optimal health
Alcohol
- provides 7 kcal of energy per gram
- not a nutrient as it does not provide a function
Use of Energy in the body
- Build new compounds
- Move muscles
- Transmit nerve impulses
- Balance ions within cells
Measure of Energy
Calorie: the amount of heat energy it takes to raise a gram of water 1 degree C used to represent energy in food
Kilocalorie: the amount of heat energy it takes to raise the temperature of 1L of water by 1 degree C
The actual measurement used in everyday life
What Influences Food Choice
- Appetite: psychological influences encouraging us to find and eat food, often in the absence of obvious hunger
- Hunger: physiological drive for food
Categories of Nutritional Status
- Desirable Nutrition: body tissues have enough of a nutrient to support normal functions and maintain surplus stores
- Undernutrition: failing health that results from a longstanding dietary intake which does not meet nutritional needs
○ Causes metabolism to slow down or even stop if nutrient stores are depleted - Overnutrition: nutritional intake greatly exceeds the body’s needs
○ In the short run, overnutrition may only cause slight symptoms like intestinal distress
○ Excessive intake leads to toxic amounts of nutrients leading to diseases
- Undernutrition: failing health that results from a longstanding dietary intake which does not meet nutritional needs
National Health Objectives of Healthy People
- Attain healthy lives free of preventable disease, disability injury and premature deaths
2. Eliminate health disparities
ABCDE’s of Nutritional Assessments
- Anthropometric assessments: measuring various aspects of the body including height, weight, body circumference and skinfold thickness
- Biochemical assessments: measurements of the concentrations of nutrients and nutrient by products in the blood, urine, feces and blood enzyme activities
- Clinical assessments: HC providers search for physical evidence of diet related sieases and focuses on potential problem areas identified from a dietary assessment○ Nutrition-focused physical exams: clinical assessments related to nutritional issues which search for evidence of nutrient deficiencies or toxicities in a head-to-toe search
- Dietary Assessment: examines how often a person eats, the types of food eaten, and their typical DI
- Environmental Assessment: provides info on the persons education and economic background which can provide information as to why they are making certain food choices
Limitations of Nutritional Assessments
- Signs and symptoms are not very specific
- Can take a long time for signs and symptoms to appear between development of poor health and the first clinical bit of evidence
- As they take a long time to develop it can be vague to link to what currently is causing it
- Can take a long time for signs and symptoms to appear between development of poor health and the first clinical bit of evidence
Red flags for Poor Nutritional Advice
- Promises of a quick fix
- Dire warnings of dangers from a single product/regimen
- Claims that are too good to be true
- Simplistic conclusiosn drawn from complex studies
- Recommendations based on a single study
- Lists of ‘good’ and ‘bad’ foods
- Recommendations based on studies that havnt been peer reviewed
Rules around selling health products
- FDA must prove a dietary supplement is unsafe before banning its sale
- Alternatively manufactures must prove food additives and drugs are safe before they can be sold
