Nutrition Flashcards
What is Nutrition?
It is the “study of food and how it affects the human body and influences health”
What are nutrients?
are biochemical substances that affect growth, development, reproduction, activity, health maintenance, and the body’s ability to recover from illness and injury
What is metabolism?
Metabolism is the “process by which the body converts food into energy”
Recommended Dietary Allowance (RDAs): Nutrition guidelines to meet nearly all healthy people
The Guidelines:
- Follow a healthy eating pattern across the lifespan
- Food and beverage choices matter
- Choose a calorie intake appropriate to maintain healthy body weight, support nutrient adequacy, and reduce the risk of chronic disease
- Focus on variety with all food groups that are nutrient-dense
- Limit calories from added sugars and saturated fats and reduce sodium intake
- Support healthy eating patterns in multiple settings nationwide, from home to school to work to communities
6 Classes of Nutrients:
Essential nutrients: Nutrients that must be supplied in diet or supplements:
1-Carbohydrate
2-Protein
3-Fat
These 3 above are macro-nutrients that provide energy to the body.
1-Vitamins
2-Minerals
3-Water
These 3 above are micro-nutrients: they regulate the body’s processes.
Non-Essential nutrients: Not essential for body function or are synthesized (made) in adequate amounts by the body
Energy balance = ?
Total energy intake - Total daily expenditure.
The amount of energy a person requires is dependent: on age, sex, activity level, weight, height, and health conditions
How is energy measured?
Energy is measured in Kcal (kilocalorie)
1 gram of carbohydrate = 4 Kcal
1 gram of protein = 4 Kcal
1 gram of fat = 9 Kcal
Daily caloric requirements: Several formulas are available. Simplest:
20 to 35 kcal/kg body weight
Glycogenesis:
excess glucose stored in form of glycogen in the liver
Carbohydrates and proteins are converted to fat in excess and stored as triglycerides in the liver or fat cells (adipose tissue)
Glycogenolysis
When glycogen is broken down into glucose for energy
Carbohydrates (CHO)
CHO: the primary source of energy
CNS relies exclusively on glucose for energy
Chief protein-sparing energy source
Easier and faster to digest than proteins and fats
All CHO converted to glucose for transport in the blood
Glucose transported to GI tract →portal vein → liver for storage
Glycogenesis: excess glucose stored in form of glycogen in the liver
Carbohydrates and proteins are converted to fat in excess and stored as triglycerides in the liver or fat cells (adipose tissue)
Glycogenolysis: When glycogen is broken down into glucose for energy
Blood glucose is regulated by the hormones insulin and glucagon
The body completely metabolizes glucose (unlike fats and proteins which leaves behind ketones - toxic byproduct)
What are Monosaccharides (simple)?
Single-stranded sugar molecule
Glucose
Fructose
Found in fruits and honey
What are Disaccharides (simple)?
Disaccharides (simple)
Double-stranded sugar molecule
Sucrose (table sugar)
Maltose (malted grains)
Lactose (milk)
Complex carbohydrates (polysaccharides)?
Starches such as cereal grains, starches, and legumes
Ideal amounts of carbs a day?
Ideally 45% to 65% of daily caloric needs
Should include 14 g of fiber/1000 kcal
How many variations of amino acids do proteins have?
Made of 22 variations of amino acids which are the basic building blocks for life:
Proteins are essential for?
Essential for the formation of all body structures:
1-genes
2-enzymes
3-muscle
4-bone matrix
5-skin and blood.
What are the 2 types of proteins?
- Complete proteins
- Incomplete proteins
Complete proteins:
Contains all essential amino acids to support growth
Animal proteins: eggs, dairy, meat
Incomplete proteins:
Lacks one or more amino acids
Plant proteins: grains, legumes, vegetables (some exceptions: soy, buckwheat, hemp, etc. )
10% to 35% of daily caloric needs
Protein Metabolism
Protein metabolism:
Ingested protein → broken down to amino acids by pancreatic enzymes in small intestine → absorbed by GI mucosa → liver→recombined into new proteins or release into bloodstream for protein synthesis by tissues and cells
Excess converted to fatty acids or used for fuel
*Breaking down protein for energy forms ketones which is toxic for kidneys in excess
Body in constant flux between tissue breakdown (catabolism) and tissue rebuilding (anabolism)
Nitrogen balance compares protein intake vs protein excretion (loss via urine, stool, hair, nails, skin) Nitrogen is a fundamental component of amino acids, which are the molecular building blocks of protein. Therefore, measuring nitrogen inputs and losses can be used to study protein metabolism.
Positive nitrogen balance (intake > excretion) occurs in growth spurts, pregnancy, lactation, illness recovering
Negative nitrogen balance (intake < excretion) occurs with starvation, and conditions such as surgery, illness, trauma, stress when the body is overwhelmed
Fats (Lipids)
A major source of energy
Insoluble in water and blood
95% of lipids in diet are triglycerides
5% are phospholipids and cholesterol
Carriers of essential fatty acids and fat-soluble vitamins
20% to 35% of total daily caloric intake (<10% from saturated and trans fat)
9 kcal/g
Unhealthy fats
Saturated fat and trans fat
Lacks double bonds between carbons leading to solid form at room temp
Animal source
Raises serum cholesterol
Healthy fats
Unsaturated fat: Mono-and poly-unsaturated fats
Contains at least one double bond between carbons; liquid at room temp
Olive oil, salmon, avocado
Lowers serum cholesterol
Where is fat metabolized?
In the small intestine
Fat metabolism process?
Occurs in the small intestine
Bile secreted by the gallbladder emulsifies fat for pancreatic lipase to break down fat more efficiently
Most fats are absorbed in the lymphatic system and transported to the liver
Only 3% of fats eaten are excreted in the stool
the body has to burn off excess fat
What is cholesterol?
Cholesterol sources: produced by the liver and consumption of animal foods
Essential for cell membrane, the precursor of steroid hormones and Vitamin D, synthesizes bile acids
LDL (low-density lipoprotein)
The “bad” cholesterol
High levels lead to plaque buildup → atherosclerosis
HDL (high-density lipoprotein
The “good” cholesterol
Carries LDL away from body to liver for processing
Triglyceride
Most common type of fat
Liver converts excess CHO as glycogen or converted to triglycerides and stored in adipose tissue
What are vitamins?
Organic compounds are required for normal metabolism and prevention of diseases related to deficiency
- Not made by the body; must be consumed
Water soluble: vitamin C and B-complex? B for blood stream
absorbed directly by the small intestine and into the bloodstream
Not stored; excess excreted in the urine
Fat-soluble: vitamins A, D, E, K
Inadequate amounts lead to deficiency syndromes
Vit C deficiency →Scurvy
Vit D deficiency →Rickets in children; osteomalacia in adults
Folate (Folate is the natural form of vitamin B9) and Iron → Anemias
Absorbed with fat and carried in the lymphatic circulation; must be attached to a protein to be transported in the blood
Excess stored in the liver and adipose tissue
What are Minerals?
- Inorganic elements found in nature (food and supplements)
- For tissue building, nerve impulse, fluid regulation, bone and blood health
- Not broken down by body
- Major minerals (macrominerals)
Required in amounts of > 100 mg/day
e.g. Calcium, phosphate, sodium, potassium, magnesium - Trace minerals (microminerals)
Essential but in low amounts < 100 mg/day
e.g. Iron, Zinc, Iodine, fluoride
2 Major types of minerals?
- Major minerals (macrominerals)
Required in amounts of > 100 mg/day
e.g. Calcium, phosphate, sodium, potassium, magnesium - Trace minerals (microminerals)
Essential but in low amounts < 100 mg/day
e.g. Iron, Zinc, Iodine, fluoride
Water?
Water is more vital to life than any other nutrient
- Major body constituent in every body cell
- Accounts for 50-60% of an adult’s body weight
* ⅔ in intracellular space
* ⅓ in extracellular space
- Average adult requirement: 2.2 -3L/day
- Water balance and levels in the body are affected by :
* renal function
* fever, perspiration, tachypnea, severe burns
* diarrhea, vomiting
* Draining fistulas and drainage tubes
* Hemorrhage
* Prolonged open abdominal surgery
Water source: fluid and food intake and produced during the metabolism of CHO, protein, fat
- Water depletion through urine, stool, insensible loss (breathing and perspiration)
Special Diets:
Vegetarian
Lacto-Ovo vegetarians
Vegans
Vegetarian Diet?
Exclusion of meat from the diet
Need a well-planned diet to avoid vitamin, protein, and iron, deficiencies
Lacto-ovo vegetarian Diet ?
Plant food diet and occasional dairy products and eggs
Risk for vitamin and mineral deficiencies
Iron deficiency
Vegan diet ?
Exclusive plant foods
Can develop megaloblastic anemia and neurologic signs of deficiency
Require fortified foods with Cobalamin (vitamin B12)
Cardiac diet?
2g of Na a day only (Cardiac diet)
Renal diet?
low K and Na
NPO vs strict NPO
?
Npo a secas you can take some medicine and ice chips.
Diabetic diet?
low carbohydrate and sugar-free
