Nutrition In Health And Dusease Flashcards
What are macronutrients?
Provide energy, calories, and dietary essential nutrients- carbs, fats, proteins
- dietary essential amino acids
- dietary essential fatty acids
What are micronutrients?
These are needed in less quantity and fulfill many functions: vitam8ns and minerals
How much energy do we expend in a day?
Estimated total energy expenditure per day(TEE)= REE(resting energy expenditure)+ DIT+ Physical activity
Light physical activity cost of energy (10-30%)
What is the resting metabolic rate (RMR) or resting energy expenditure (REE)?
Resting metabolic rate (RMR) or resting energy expenditure (REE) is the energy expended to carry out normal body functions (range of 60-75%). The RMR is about 10% higher than the basal metabolic rate (BMR). The BMR under specific conditions but is mostly estimated. The RMR is dependent on age, gender temperature, injury factor etc. what
How does hypo and hyperthyroidism affect RMR?
RMR is increased in hyperthyroidism (weight loss)
RMR is decreased in hypothyroidism (weight gain)
What is the thermal effect of food?
The thermic effect of food or diet induced thermogenesis (DIT) is the heat generated after food intake (10% for a mixed diet)
How can the daily total energy expenditure TEE be estimated?
The BMR is in general roughly estimated as 24 kcal/kg/day body weight (1 kcal /kg/hour) for males. (Females with less lean muscle mass : 0.9 kcal/kg/ hour)
The RMR is set in this specific calculation example as 75% of the TEE.
BMR for 60 kg person: 25 kcal/day = 1,584 kcal/day
RMR is set as 75% of TEE:
TEE= 1584 kcal/ 0.75= 2,112 kcal/day
How much energy is available from the major food components (kcal/g)?
- Carbohydrates and proteins generate each the same amount of energy 4 kcal/g
- Fats generate more than twice this amount: 9kcal/g
- Alcohol generates nearly the same as fats: 7 kcal/g
Note: fiber isn’t calculated to contribute kcal to the diet
How many grams of specific nutrients are needed for a particular diet?
Calculation example:
This diet requires 40% carbohydrate, 30% fat and 30% protein. TEE is set as 2,000 kcal/day
First: calculate how many kcal of the respective nutrient is needed for the TEE. Then you have to decide the kcal by the respective kcal/g to give you the amount in grams
Carbohydrate: 40% 0.4 x 2,000 kcal= 800 kcal/4/g= 200 g
Fats: 30% 0.3x2,000 kcal= 600 kcal/9 kcal/g= 67 g
Proteins: 30% 0.3x2,000 kcal= 600 kcal / 4 kcal/g= 150 g
Why are dietary lipids important?
Important for energy metabolism and storage of fat in human adipose tissue. Triacylglycerides represents the majority of dietary fat and excessive intake can lead to obesity
What happens when your diet doesn’t provide dietary lipids?
The diet has to provide lipid-soluble vitamins
-The dietary essential fatty acids are needed for membrane fluidity, are precursors fir eicosanoids and they can cross the blood brain barrier. Deficiency can lead to scaly dermatitis
What is the purpose of cholesterol?
Needed for plasma membranes and for synthesis of bile acids, steroid hormones and vitamin D. If not provided by the diet, cholesterol is synthesized in the liver
What are the physiologic effects of omega-3?
Dietary doses of DHA and. EPA reduce:
- Arrhythmia
- Heart rate
- Blood pressure
What are the products of linoleic acid(omega-6)?
Arachidonic acid, omega 6- eicosanoids
What are the products of a-linolenic acid (omega 3)?
EPA-Eicisanoids—>DHA(brain,vision)
Compare the Mediterranean diet compared to the western diet
Both diets had 38% of fat but with different composition. Meditteranean diet has more monounsaturated fatty acids (oleic acid 18:1) and less saturated fats.
Meditteranean diet lowers lipid cardiovascular risk factors
Olive oil (extra virgin)
Fish oils, nuts(omega 3)
Plant-based food, fiber-these. 3 are high in monounsaturated fats
Unlike…
Low saturated fat
Low red meat
What are the health concerns of carbohydrates ?
A diet rich in refined sugar can lead to obesity and diabetes and also to caries
High-fructose corn syrup (HFCS 55) is added to many food items (55% fructose and 42% glucose). It contains the mixed monosaccharides and the consumption of high levels of fructose May be harmful.
Foods with a high glycemic index sharply elevate blood glucose levels resulting in a strong response in elevated serum insulin
What is the glycem8c index?
Defined as the area under the positive blood glucose r3sponse curve when compared to the same amount of a control. The control in most cases is 50 g of glucose which is set at 100
As an example bananas have a GI of 52 because the area under the banana curve is 52% is that of glucose
The GI is affected by several food factors like carbohydrate digestibility, fiber and fat content
Descr8be properties of food with low glycemic index
High GI: Above 70
Low GI: Less than 55
Foods with low glycemic index(whole wheat, vegetables, legumes, fruit)
- slowly increase blood glucose
- Have a low maximum effect
- Sustain blood glucose levels longer
- Cause less fluctuation of insulin release
- Improve blood glucose control in diabetic patients
- Increase satiety abs may help to limit caloric intake
What are the actions of dietary fiber?
Fiber absorbs water in the intestine increasing bowel motility. S9luble fiber is fermented by bacteria whereas insoluble fiber passes through the digestive tract largely tract
What are the health eff3cts if dietary fiber?
- Reduces constipation and hemorrhoid formation, soften stools
- Increases bowel motility, thus reducing exposure of gut to carcinogens
- Decreases absorption of dietary fat and cholesterol increases fecal loss of cholesterol
- Delays gastric emptying. Generates sensation of fullness. Reduces postprandial blood glucose concentration
Where can soluble fibers be found?
Oat bran, barley, nuts, seeds, beans, lentils, fruits, (citrus, apples), strawberries, vegetables
What foods contain insoluble fibers?
Whole wheat, whole grain products, vegetables, and wheat bran
How can we analyze the quality of some common dietary proteins?
PDCAAS= protein digestibility corrected amino ac8d score
This score is based on the profile of essential amino ac8ds after correcting fir the digestibility 8f the protein
What are the dietary essential amino acids?
PVT TIM HALL
PVT-phenylalanine, valine, tryptophan
TIM- threonine-isoleucine-methionine
Hall- histidine, arginine, lysine, leucine
In the past arginine was grouped as a dietary essential amino acid for adults
How can we get optimal dietary amino ac8ds in plants?
A mixture of plant food sources eaten at the same time can lead to an optimal score
What 8s nitrogen balance about?
The dietary protein requirement can be determined by the calculation of the nitrogen balance (NB)
Most healthy adults are in (equal) nitrogen balance
Nitrogen intake equals nitrogen output
What does positive nitrogen balance ?
Dietary amino acids are used for protein synthesis and less urea is formed
Nitrogen intake exceeds nitrogen excretion
Causes: positive nitrogen balance is found in tissue growth during childhood, pregnancy or recovering from an emancipating illness Note: this requires the dietary essential amino acids
Describe negative nitrogen balance
Dietary nitrogen intake is smaller than nitrogen release. Less protein synthesis and more muscle protein degradation
Nitrogen release exceeds nitrogen uptake
What are the causes of negative nitrogen balance ?
- Inadequate protein and lack of dietary essential amino acids
- Increased tissue protein degradation (muscle)
- Physiological strsss: trauma, burns, illness or surgery
What is respiratory quotient ?
Indicates whether mainly carbohydrates or fats are metabolized
The RQ is the ratio of oxygen usage to carbon dioxide output
Contrast the respiratory quotient for carbohydrate metabolism and fat metabolism
RQ for carbohydrate metabolism is 1.0 as for each molecule of oxygen consumed one carbon dioxide molecule is formed. After a meal mostly carbohydrates are metabolized and the RQ is 1.
RQ for fat metabolism averages 0.7 as for each 100 molecules of oxygen only 70 carbon dioxides are formed due to generation of metabolic water. During starvation mostly fatty acids are metabolized and the RQ is 0.7
What is the function of Ghrelin?
- peptide hormone produced by the stomach
- Stimulates appetite and increases desire to eat
- Drives hunger and food intake
- Sleep deprivation can increase ghrelin levels
What are the functions of Cholecystokinin(CCK) and PYY?
- Peptide hormones prod7ced by the intestine
- CCK by the duodenum and jejunum
- PYY by the ileum and colon
- Stimulate satiety.
What are the short term regulations of appetite?
Short term signals Ghrelin action is counteracted by CCK and PYY
What are the long term signals of appetite ?
Long term- signals
Ghrelin action is counteracted by leptin and insulin
What is the function of leptin?
- Peptide hormone produced by adipose tissue
- Secreted in proportion depending on the size of fat stores
- Decreases appetite and suppresses desire to eat
- Stimulates metabolic rate and increases energy expenditure
- Overeating and chronic high fructose consumption may lead to leptin resistance and obesity
How does insulin counteract ghrelin ?
Peptide hormone produced by the B-cell of pancreas
What is the protein energy malnutrition (PEM)?
PEM is commonly seen in patients with medical conditions that lead to decreased appetites or altered digestion and absorption
It is found in hospitalized patients with: major trauma, depressed immune system, infections and chronic diseases
How can protein energy malnutrition be treated?
Treatment can require intravenous fluids and Total Parenteral Nutrition (TPN)
In the elderly PEM can result from metabolic changes or result from less food intake due to depression
What diseases can come from protein energy metabolism (PEM)?
In children is a serious world-wide problem and results from inadequate provision of food
Kwashiorkor: deficient protein
Marasmus: defucient calories
Describe BMI
Anthropometric measurements
(Weight in kg)/ squared of height in meters)
-underweight individuals = BMI smaller than 18.5
Healthy range= BMI 18.5-24.9
Overweight individuals = BMI 25-29.9
Obese individuals = BMI larger than 30, severe greater than 40
What are the indicators of nutritional status?
- Body mass index (BMI)
- Estimation of body muscle mass vs adipose tissue- triceps skin fold (TSF), mid-arm muscle circumference, bio electric impedance analysis (BAI), DEXA scan
- Anatomic differences in fat deposition- Body fat location is important in risk assessment for metabolic syndrome and CHD
How can triceps skin fold (TSF), estimate body muscle mass vs adipose tissue?
Skinfold thickness estimates. Body fat stores because body fat is normally located at subcutaneous region
How can mid-arm muscle circumference, estimate body muscle mass vs adipose tissue?
Often used to estimate skeletal muscle mass
How can bioelectric impedance analysis (BAI), estimate body muscle mass vs adipose tissue?
A low-level safe electrical current is sent through the body: measures body fat %
How can DEXA scan, estimate body muscle mass vs adipose tissue?
Dual- energy x-ray absorltiometry scan measures bidy fat. (It is asking used to measure bone density)
Why is body fat. Location important?
Important in risk assessment for metabolic syndrome and CHD
What is the significance of waste to hip ratio?
- Greater than 0.8 for women or greater than 1 for men
Apple shape or upper body obesity, more fat deposition in the trunk. Higher amount of visceral fat
- Less than 0.8 for women or less than 1 for men:
Pear shaped or lower body obesity, more fat deposition in hips and thighs
Explain the significance if anatomical fat deposition (visceral + subcutaneous)
Subcutaneous fat deposits: (80%-90% body fat)
- Located just under the skin
- Are in the upper abdominal and gluteal-femoral regions. Fatty acids released enter general circulation
Visceral fat depots(10%-20% body fat)
-Located within abdominal cavity in close association with the digestive tract
-Fatty acids are released into portal vein and can lead to higher hepatic VLDL formation with risk of coronary heart disease
What are the biochemical indicators of the nutritional status?
- A diet of proteins and amino acids leads to a low serum albumin level. The dietary amino acids are needed for the synthesis other serum proteins
- The nutritional status of fasting or starvation leads to an increase in serum free fatty acids released from fat cells
- Increased levels of serum free fatty acids are also found in patients with insulin resistance. This metabolic abnormality is extremely investigated and may have several causes
