8 - Diet, Nutrition, Energy Balance Flashcards
2015 Dietary guidelines from HHS & FDA
- Eating pattern w/ Appropriate Calorie Level
- –> reduce risk of chronic disease
- Variety / Nutrient Density / Amount
- within all food groups in recommended amounts
- Diatary guidelines are Always Changing:
- British study that says fats/saturated fats REDUCE CHANCE OF STROKE??
What food groups should you limit calories from?
Added Sugars
Saturated Fats
Sodium
Ways that WATER is LOST
- Regularly:
- Respiration / Sweating / Excretion
-
EXTRA LOSS FROM:
- Prolonged Sweating
- Vomiting
- Diarrhea
- EXTENSIVE BURN INJURIES
-
Certain Diseases
- __that affect water / Na excretion
Daily Recommended Water Intake
3.7 L / day for Adult Males
BEWARE: HYPONATREMIA
Drinking TOO MUCH water -> Diluted Sodium levels in body
CELLS CAN SWELL
Lipids (TG’s)
Macronutrient Energy Production
-
Beta Oxidation (in MITO)
-
FA’s -> Acetyl-CoA
- -> TCA CYCLE
-
FA’s -> Acetyl-CoA
Carbs
Macronutrient Energy Production
- Polysaccharides -> Monosaccharides
- -> Glycolysis
- -> TCA Cycle
- -> Glycolysis
Proteins
Macronutrient Energy Production
- Proteins -> Amino Acids + NH2
- NH2 -> Ammonia / Urea cycle
- Carbons -> TCA cycle
Basal Metabolic Rate Formula
BMR =
( weight in kg ) x 24 Cal/kg
or 100 kj/kg
- Energy needed by awake person at REST
- Only accounts for 60-70% of total energy expenditure for sedentary individuals
- Exercise / Cold / Fever -> INCREASE BMR
- Hormones can also affect BMR
- Hyperactive Thyroid -> RAISE BMR
% of BMR Factor for Active Adults
Sedentary = x30%
Moderately Active = x40%
Active = x50%
Protein / AA’s
FOOD SOURCES
Meat / Fish / Legumes (tofu)
Dairy / Cereal
Lipids (TG’s)
FOOD SOURCES
Meat / Fish
Oily seeds
Nuts
Vegetable Oils
Carbs
FOOD SOURCES
Veggies
Fruits
Cereals
Daily Value (DV) levels are high / low when?
HIGH > 20%
LOW <5%
- Based on 2000 Cal/day
- SERVING SIZE MUST BE SPECIFIED
Reading a Nutritional Food Label
-
Serving Size
- needs to be specified
- Check Calories
-
LIMIT THESE NUTRIENTS:
- Fat / Cholesterol / Sodium
-
Get enough of these nutrients:
- Vitamins / Iron / Fiber
- Footnotes
Glycemic Index
GI
-
GI of 100:
-
AUC under 2 hour curve of measured blood glucose
- after ingestion of 50g of glucose
-
AUC under 2 hour curve of measured blood glucose
- Higher GI = Worse for you
- Used to help DIABETIC patients to avoid foods that would greatly raise BG levels
Factors that affect Glycemic Index
- Complex, many factors involved:
- Portion size
- Fiber content
- processing
- Physiological state of subject
Foods with HIGH GI >70
Candy
Bread
Rice
Potatoes
Food w/ Low GI <55
Fruits
Unsweetened dairy products
Nuts
Glycemic Load
GL
GL = GI x Amount of Carbs (grams)
- Factors in PORTION SIZE
- more useful than GI, in limiting postprandial hyperglycemia
Carbohydrate Intolerance
- Typically caused by:
-
defect in digestive enzyme
- sucrase or lactase
- Impaired Sugar Transporter
-
defect in digestive enzyme
- RBS - Symptoms
- reducing sugars in stool
- fermentation of sugars by bacteria in colon
- Acetate / propionate / gasses
- Diarrhea
Lactose Intolerance
Type of Carbohydrate intolerance
Defect or Lack of LACTASE
GENETIC COMPONENT
- Avoid dairy products
- But, monitor levels of:
-
Calcium
- can get from dried beans / leafy veggies
- Vitamin (d)
- Phosphorous
-
Calcium
What are the ESSENTIAL CARBS?
-
Technically there are NO ESSENTIAL SUGARS
- as long as you have sufficient protein
- Protein -> AA’s -> carbs
- as long as you have sufficient protein
-
VITAMIN C might be an exception
- needed as a COFACTOR
- for hydroxylations
- scurvy / hemorrhage / loose teath / wound healing
- needed as a COFACTOR
What are the 9 Essential Amino Acids?
H I L L T T MPV
His / Ile / Leu / Lys
Thr / Trp
Met / Phe / Val
What Extra AA’s are needed for children ?
Growing Children need extra
Arg
What extra AA’s are needed for premature infants?
Premature infants may need extra:
Cys
Tyr
Celiac Disease
“Toxic Protein”
-
Immune sensitivity to GLUTEN
- -> inflammation
- Damages small intestine fxn &
- small-scale structure
- diarrhea / malnutrution
-
Gluten is found in:
-
Wheat / Barley / Rye
- gliadin / glutenin
-
Wheat / Barley / Rye
Can you have TOO MUCH Protein in diet?
- No tolerable upper limit yet:
- Normal = ~15% of daily caloric intake
- Possible to survive with a diet:
- free of carbohydrates
- Large amounts of meat / fat
- Can result in some side effects if >45% of calories
Effects of high-protein diet?
>45 % of total calories
Ketoaciduria
Calcium loss in urine
Renal HYPERtrophy + Damage
Two Essential Fatty Acids
PUFA (polyunsaturated FA’s)
-
Linoleic Acid
- w-6 or n-6 FA
-
Alpha-LinoleNIC Acid
- w-3 or n-3 FA
Linoleic Acid
n-6 PUFA
- Essential Fatty Acid, most abundent PUFA in US Diet
- Provides eicosanoids (arachidonic acid)
- -> Prostaglandins + Leukotriens
- Shingolipids
-
Gene regulatory Proteins
- PPARs
-
Signal Transduction pathways
- form phosphoinositol-containing lipids
- Provides eicosanoids (arachidonic acid)
Deficiency in n-6 PUFA ( Lineleic Acid)
Symptom takes MONTHS to appear
- Compromise the Skin-Water Barrier
- major role for sphingolipids
-
Blood Clotting / BP / Immune Fxn
-
n-6 -> Arachidonic acid
- -> prostaglandins / leukotrienes
-
n-6 -> Arachidonic acid
-
Signal Transduction Pathways
- that use inositol as phospholipids
- PPAR
Alpha - linoleNIC acid
n-3 PUFA
- Essential FA, present in:
- Soybeans
- Canola Oil
- Flax Seeds
- Oily Fish (salmon)
- deficiency -> visual acuity loss & peripheral neuropathy
Deficiency in n-3 alpha linoleNIC acid
-
LOSS OF VISUAL ACUITY
- PERIPHERAL NEUROPATHY
- Can be compensated possibly by n-6 PUFA (linoleic acid)
LCFA Bad Effects
- LCFA -> Lumen of Small Intestine can be harmful
- esp in INFANTS & Small CHILDREN
- __Mucosa becomes more resistant as you AGE.
- typically not a problem w/ adults
- esp in INFANTS & Small CHILDREN
-
Disrupt Mucosal Barrier
-
Inflammation / Infection
- -> Enterocolitis / Diarrhea
-
Inflammation / Infection
LCFA GOOD effects
- Induce SATIETY
- inhibition of FOOD INTAKE
- Possibly involves peptide hormone signals such as:
- Ghrelin
- Apolipoprotein A-4
- Choleecystokinin
Marasmus
Protein-Energy MALnutrition
Super Skinny
Lethargy / Impaired Immunity / Anemia
-
Insufficient Energy Intake
- lacking Fuel for the body in general
- Loss of SC Fat & Skeletal muscle
Kwashiorkor
Protein-Energy MALnutrition
Swollen Abdomen
Edema / Fatty Liver
+ Lethargy / Impaired immunity / anemia
- “First - Second Child”
- sickness in children who were weaned when a second child was born
- no more milk / protein
- sickness in children who were weaned when a second child was born
- High starch diet (yams / cassava / bananas)
How does the body metabolically adapt to Starvation?
- Carbs (glycogen) are extensively DEPLETED in just a few days
-
Lipolysis -> FA’s
- FA’s to liver -> Gluconeogenesis
- Glucose for the brain
- FA’s to liver -> Gluconeogenesis
-
Brain starts to use KETONE BODIES
- ketone bodies increase due to lack of glucose
- from FATS
- ketone bodies increase due to lack of glucose
Ketosis
- Unusually HIGH concentration of Ketone bodies in the BLOODSTREAM
- 0.3 - 7.0 mmol/L
- Excess ketone bodies are filtere out by KIDNEYS -> Urine
- -> results in Ketonuria
-
Deplete stores of ions such as:
- Na / K / Phosphate
- -> Dehydration
Ketonuria
- Result of Ketosis
-
Ketone Bodies being filtered out by the kidneys and excreted in the urine
- exert osmotic effect on kidneys
- resulting in MORE URINE than usual
- depleted body stores of IONS:
- NA / K / P
- -> Dehydration
- depleted body stores of IONS:
-
Ketone Bodies being filtered out by the kidneys and excreted in the urine
Types of Ketone Bodies
Acetoacetate
B-Hydroxybutyrate
Acetone
Where and Why are Ketone Bodies created?
- When there is not enough OXALOACETATE for the TCA CYCLE
- Acetyl-CoA -> Ketone Bodies
-
Oxaloacetate is used in both GLUCONEOGENESIS and the TCA cycle
- during starvation, there is not enough of it
- Fatty Acids and Amino acids still supplement Acetyl-CoA
- which is converted into Ketone bodies when TCA can’t occur
How do organs use KETONE BODIES?
- Direct use of Ketone Bodies:
- Cardiac / Skeletal Muscle
- Renal Cortex (Kidney)
- Brain adapts to use them as fuel
-
LIVER
- liver lacks the key enzyme to breakdown ketone bodies
What causes Ketosis?
-
low CARB intake (high protein diet, or lipids only, or starvation)
- Body uses FA’s & AA’s instead of carbs
- Glycerol + AA’s are used for gluconeogenesis
- Body uses FA’s & AA’s instead of carbs
-
Diabetes
- Glucose not being taken up by tissues
- = acts as if Starved for energy
- Metabolism shifts to fasting/starvation
- -> Ketosis
- DEHYDRATION
- Metabolism shifts to fasting/starvation
- = acts as if Starved for energy
- Glucose not being taken up by tissues
Oxaloacetate
- Used in both the TCA Cycle & Gluconeogenesis
- In starvation / low or no Carb diet:
- Body is excessively going through Gluconeogenesis
- which uses up Oxalacetate to produce glucose
-
TCA Cycle can not occur w/o oxalacetate
- -> so Acetyl-CoA builds up from AA’s/FA’s
- Acetyl-CoA is then over converted into Ketone Bodies
- -> KETOSIS
- Acetyl-CoA is then over converted into Ketone Bodies
- -> so Acetyl-CoA builds up from AA’s/FA’s
- Body is excessively going through Gluconeogenesis
How are Ketone bodies catabolised?
-
@Non-Helpatic Tissues:
- Ketone Bodies -> Acetyl-CoA
- to produce energy for cell
- Ketone Bodies -> Acetyl-CoA
- Rate limiting step = Second Step
-
Enzyme that catalyzes this step is not expressed in the LIVER
- -> liver itself can not consume ketone bodies
-
Enzyme that catalyzes this step is not expressed in the LIVER
Ketoacidosis
Acidosis + Ketosis
- Most common with Diabetes patients paired with:
-
Extreme / Uncontrolled Ketosis
- more common with Type 1
-
Extreme / Uncontrolled Ketosis
Symptoms of Ketosis
- High levels of ketone bodies (acetone / hydroxybutyrate)
- -> BAD BREATH
- acetone might smell like ethanol
-
Can result in Acidosis
- pH of blood drops below <7.3 pH
- Together Acidosis + Ketosis = Ketoacidosis
Acidosis
- Can be caused by Ketosis
- Ketone bodies acidify environment
- Acidosis is defined by <7.3 blood pH
-
reduce the oxygen carrying capacity of erythrocytes
- very serious condition
-
reduce the oxygen carrying capacity of erythrocytes
- Can develop to Ketoacidosis