Exam 2 NFS
Protein balance
- Nitrogen intake - nitrogen loss - Intake > loss: positive nitrogen balance • Growth, recovery from injury, trauma, or illness • Building and repairing tissues - Loss > intake: negative nitrogen balance • Untreated illness or injury - Loss = intake: nitrogen equilibrium • Healthy adult
Carbohydrate High Fiber:
-(>50-60g) -Hard, dry stools; decreased absorption; inadequate calories
Long Term Impacts of Intoxication- Chronic Damage to Cells
-Alcohol is highly toxic and can kill cells quickly -Acetaldehyde is also toxic and a probable carcinogen --->Long term exposure in the liver causes damage -Metabolism produces reactive forms of oxygen (oxygen radicals) damages DNA and lipids --->Damage to cell membranes kills the cell --->Damage to DNA causes apoptosis (programed cell death) or cancer
ALCOHOL Absorption
-Alcohol requires no digestion, specific transport mechanisms or receptors -Stomach absorbs 20 % via simple diffusion, remainder in small intestine. -If ingested with food, especially high fat foods, absorption is slowed -Alcohol is found wherever water is distributed in the body --->Easily moves through cell membranes, damaging the proteins in membranes
Diabetes
-Fasting blood glucose level at or above 126 mg/dl -Hemoglobin A1c level at or above 6.5% Two main forms of diabetes: -type 1 -type 2
protein Digestion
-Goal: digest to amino acids to be absorbed• Cooking starts to denature proteins Mouth: no protein digestion Stomach -Hydrochloric acid denatures --->Gastrin (hormone) -Pepsinogen + HCl —>pepsin (enzyme) -Proteins —> polypeptides Small Intestine -Cholecystokinin (CCK) --->Hormone that stimulates release of enzymes ----->Polypeptides—>shorter peptides and amino acids Large intestine -No protein digestion
Monosaccharides
-Hexose: 6 carbon structures Glucose -Most abundant -Linked together with other sugars in our diets -"Blood sugar" Fructose -Found in fruits, vegetables, honey, and high- fructose corn syrup Galactose -Most in our diets is combined with glucose to form lactose (milk sugar) Sugar alcohols -Derivatives of monosaccharides -Sorbitol, mannitol, and xylitol -Sweeten sugarless gums and diabetic foods
Digestible Polysaccharides: Glycogen
-Storage form of carbohydrate in humans and animals -Linked by alpha bonds -More highly-branched than amylopectin -Mainly stored in liver and muscle cells
Glucose intolerance
-Type 1 Diabetes; Type 2 Diabetes -Abnormal regulation of blood glucose levels Hyperglycemia -More common -High blood glucose levels -Commonly associated with diabetes and Metabolic Syndrome Hypoglycemia -Low blood glucose levels
Why are "Good Cholesterol" or "Bad Cholesterol" in quotations ?
-We are actually talking about LIPOPROTEINS not cholesterol -We need both -->But we want LDL-C to be lower and HDL-C to be higher to decrease risk of heart disease
Lipid absorption
-~95% of fat consumed is absorbed --->End products are absorbed by the cells in the small intestine -Short and medium chain FAs --->Water soluble ---->Absorbed directly into the bloodstream (cardiovascular system) ----->—>Liver -Long chain FAs - Lipoproteins -->Water insoluble -->Not absorbed directly into the bloodstream -->Re-formed into triglycerides in the cells in the small intestines
major types of carbohydrates
1. Monosaccharides 2. Disaccharides 3. Oligosaccharides 4. Polysaccharides
Disaccharides
2 monosaccharides linked together in a condensation reaction Maltose -2 glucose molecules -Found in seeds and alcoholic beverages Sucrose -1 molecule of glucose, 1 molecule of -Table sugar; Sugarcane, sugar beets, maple tree sap Lactose -1 molecule of glucose, 1 molecule of galactose -Milk and milk products
Recommended intake of carbohydrates: AMDR: ? R D A is ? Supplies adequate ... for brain and central nervous system Carbohydrates in our diets should include mostly: ...
AMDR: 45-46% total energy intake R D A is 130 g/day Supplies adequate glucose for brain and central nervous system Carbohydrates in our diets should include mostly: -Fiber rich fruits, vegetables, and whole grains -Little added sugars and caloric sweeteners
Very- High Fiber Diets
Above 50 to 60 g/day can cause health risks. Hard, dry stools if fluid intake is low Hemorrhoids,rectal bleeding,intestinal blockage Decrease in absorption of minerals (zinc, iron) Increasing risk of deficiencies Special concern for young children, elderly, malnourished May not be getting adequate amounts of foods and nutrients May cause a sense of fullness and reduce overall intake of foods
Alcohol Metabolism: 3 Pathways
Absolute priority is to metabolize alcohol cannot be stored in the body 3 pathways: Alcohol dehydrogenase (A D H) pathway Microsomal ethanol oxidizing system (MEOS) Catalase pathway
Protein Absorption
Active absorption -Requires energy Amino acids delivered to cells around the body as needed Unused amino acids go to liver -Protein synthesis -Energy needs -Conversion to glycogen and fat -Released back into the blood stream
Health concerns related to carbohydrates intake:
Adequate intake of carbohydrates is important for: -Maintaining health -Decreasing risk of chronic disease Excessive intakes can be harmful to overall health
alcohol absorption
Alcohol is absorbed in the stomach and small intestine into the bloodstream
Essential fatty acids
Alpha-linolenic acid (omega-3) -Alpha-linolenic acid -Produce EPA & DHA --->EPA & DHA ------->Eyes and brain ------->Normal growth and cognitive development Linoleic acid (omega-6) -Linoleic acid -Produce arachidonic acid Functions -Proper functioning of all physiological systems -Converted to other omega FAs Deficiency -Flaky skin -GI -Impaired immune function Other FAs -Eicosanoids -->Hormone-like effects ----->Regulate immune and cardiovascular systems -->Omega-6 ----->Promote inflammation, constriction of blood vessels -->Omega-3 ----->Reduce inflammation, dilate blood vessels, prevent blood clot formation ----->Lower blood pressure --->BALANCE
Sources of protein: US vs. Global
American diet -65% animal sources (meat, poultry, fish, milk, cheese, eggs) Worldwide -35% animal sources
Indigestible carbohydrates
Beta bonds Functions: Insoluble Bristle brush - keeps things clean and moving Soluble Gummy -- feeds bacteria, binds to cholesterol, and slows down absorption of sugar
Short Term Impacts of Intoxication
Brain: Slows down the chemicals and pathways your brain uses to control your body, altering mood, reflexes and balance. It also can contribute to learning, memory, and sleep problems. Heart: Increases your heart rate and expands your blood vessels, making more blood flow to the skin (which causes you to feel warm), however, this heat passes through the skin, causing temperature to fall after it has risen. Digestive: Promotes an increase in digestive juices. Alcohol also irritates the small intestine and colon where it is further broken down and absorbed. It can affect the speed that food moves through them, which may result in abdominal pain, bloating, and diarrhea. Kidney: Alcohol is a diuretic , impacting hormones that regulate fluid and electrolyte balance
Sterols
Cholesterol is the primary dietary sterols -Both plants and animals have sterols -Only animal products have cholesterol --->Our bodies make cholesterol in our liver --->WE DO NOT NEED TO EAT CHOLESTEROL --->We may make too much cholesterol if we eat too much saturated fat, trans fats, or too many calories -Cholesterol functions --->Bile acids --->Sex hormones (testosterone, estrogen) --->Vitamin D --->Cell membranes --->Steroid hormones -Reproduction, energy metabolism, electrolyte balance
Protein Recommended Intakes AMDR RDA complete vs complementary protein
Complete protein - all 9 essential amino acids Complementary protein - combine two or more foods to make complete protein AMDR: 10-35% total kcals RDA: 0.8 g per kg body weight 1 kg =2.2 lb Weight (lb) / 2.2 = weight (kg)
Oligosaccharides
Complex carbohydrates 3 to 10 sugar units Raffinose and stachyose: -Onions, cabbage, broccoli, whole wheat, legumes -Contain beta bonds -Pass indigested into the large intestine -Bacteria metabolize, producing intestinal gas Beano®: -Enzyme preparation that helps break down indigestible oligosaccharides
Lipids: Composed of: Insoluble in ??? ? kcal/g Fats-? Oils-?
Composed of: Carbon Hydrogen Oxygen Insoluble in water Hydrophobic 9 kcal/g Fats Solid at room temperature Oils Liquid at room temperature
alcohol composed of
Composed of: Carbon Hydrogen Oxygen 7 kcal/g Alcohol is a very small molecule and slightly lipophilic (doesn't have a charge requiring it be dissolved in water) so can enter cells/ tissues Alcohol is transported to the liver to be broken down The primary pathway (ADH) breaks down ethanol >acetaldehyde > acetic acid (which we can use to produce energy) Most can metabolize one drink in 1-2 hours. If alcohol intake exceeds this alcohol accumulates in the bloodstream
Protein -composition -? kcal/g -amino acids -denaturation -structure
Composition: Carbon Hydrogen Oxygen NITROGEN 4 kcal/g Amino acids = building blocks 20 total amino acids are needed in the body 11 nonessential 9 essential Linked together by peptide bonds to form proteins Between amino group & acid (carboxyl) group Denaturation: Unwinding & unfolding of tertiary structure Heating, acid, beating, enzymes Destroys biological function Structure: Primary - amino acid sequence Secondary -interaction of amino acid side chain Tertiary - protein folding Quaternary - multiple protein chains
Recommended intakes of sugar:
Dietary Guidelines for Americans and World Health Organization: -Limit added sugars to no more than 10% of daily total energy intake The Institute of Medicine's Food and Nutrition Board: -Upper limit of 25% of energy intake from added sugars American Heart Association: -Upper limit of sugar intake should be half of one's discretionary calorie allowance
Protein quality: Digestibility, completes. incomplete
Digestibility -Proportion of amino acids absorbed -Animal sources: 90-100% - Plant sources: 70% Complete vs. incomplete -Complete: contain all 9 essential amino acids --->Animal sources: all complete proteins except gelatin -Incomplete: missing 1 or more essential amino acid --->Plant: all incomplete except soy, amaranth, and quinoa Complementary proteins -2 incomplete protein foods combined = a complete protein food
Digestible Polysaccharides: Starch
Digestible Polysaccharides: Starch -Storage form of glucose in plants Amylose: Unbranched chain of glucose molecules Amylopectin: Highly- branched chain of glucose molecules, mostly alpha bonds -More branches, more sites for enzyme action -Faster increase in blood glucose levels • legumes, tubers, grains
Functions of Carbohydrates in the Body: -Digestible carbohydrates are broken down to glucose -Indigestible carbohydrates play a role in maintaining health of the G I tract and overall health
Digestible carbohydrates are broken down to glucose -Primary source of energy -Spare protein from use as energy -Prevent ketosis Indigestible carbohydrates play a role in maintaining health of the G I tract and overall health -Prevent constipation and diverticular disease -Enhance management of body weight, blood glucose levels, and cholesterol levels -Promote bowel health -Reduce the risk of colon cancer -Reduce obesity risk -Enhance blood glucose control -Reduce cholesterol absorption
Too much protein:
Effect on kidneys -Excretion of excess nitrogen -Creation of urea High intake of animal proteins -Risk of CVD Increased calcium loss Protein supplements Amino acid supplements -AA imbalance -Toxicity
Functions of Proteins:
Energy Very little for healthy individuals Primarily carbohydrates and lipids 4 kcals/g Structure Collagen Muscles Skin Body cells Regulatory Forms enzymes and hormones Transport Examples: hemoglobin and Lipoproteins Acid/base balance (pH) Immune system Maintain fluid balance Edema
Carbohydrates Digestion:
Food preparation starts digestion of carbohydrates -Cooking softens tough, fibrous tissues -Starch granules swell as they soak up water, making them easier to digest Begins in the mouth with salivary amylase in saliva -Breaks down starch into smaller polysaccharides and disaccharides Salivary amylase is inactivated in the stomach Pancreatic amylase and dextrinase pick up digestion in the small intestine Disaccharides are digested by enzymes in the absorptive cells of the small intestine -Maltose —-->(maltase) Glucose + Glucose -Sucrose —-->(sucrase) Glucose+Fructose -Lactose —-->(lactase) Glucose + Galactose Most carbohydrate digestion and absorption take place in the small intestine Indigestible carbohydrates cannot be broken down Pass into the large intestine Fermented by bacteria into acids and gasses or excreted
Carbohydrates Absorption:
Glucose and galactose -Absorbed by active absorption -Pumped into absorptive cells with sodium Fructose -Absorbed by facilitated diffusion -Slower absorption than glucose or galactose -Some fructose is converted to glucose in absorptive cells -Rest is converted in the liver -Galactose is converted to glucosein the liver -Glucose is then sent to cells for use -Liver stores extra as glycogen -If glycogen storage capacity is exceeded, glucose is converted to fat -Stored in adipose tissue
Carbohydrate High sugar:
Increase risk of weight gain, CVD, triglycerides, LDL
Lactose intolerance
Insufficient lactase Lactase production begins to decrease after early childhood. Primary lactose intolerance -Insufficiency of lactase production -Symptoms include abdominal pain, bloating, gas,Diarrhea -Amount of lactose tolerance varies by individuals, but hard cheeses, yogurt, and acidophilus milk are more easily tolerated Secondary lactose intolerance -Conditions of the small intestine such as Crohn's disease and diarrhea damage the lactase producing cells -Causes temporary symptoms
protein malnutrition
Kwashiorkor - protein deficiency Marasmus - protein and energy deficiency
Carbohydrates in the Body
Liver: Fructose + galactose —>converted to glucose Glucose used by cells Excess glucose stored as glycogen (liver and muscle) Excess glucose converted to fat , stored in adipose tissue
How do we improve our LDL-C & HDL-C levels?
Lower LDL-C by: 1. Follow a heart healthy diet -Limit saturated fat, trans fat, and extra calories -Increase fruits, vegetables, whole grains and legumes 2. Exercise 3. Maintain a healthy weight Increase HDL-C by: 1. Follow a heart healthy diet -Increase unsaturated fats from fish, nuts, seeds, and liquid plant oils (canola or soybean) -Exercising for at least 30 minutes 5 times per week -Quit smoking
Type 2 diabetes lifestyle modifications? medications?
Most common type of diabetes Insulin resistance or loss of responsiveness by cells to insulin -Glucose is not readily transferred into cells and builds up in the bloodstream Treatment includes lifestyle modification and medication use Lifestyle modification: -Nutritious diet -Physical activity -Weight loss Medications: -Oral -Insulin injections
Lipid digestion
Mouth -Lingual lipase -Limited Stomach -Gastric lipase --->TGs—> monoglycerides -Limited Small intestine -Majority of lipid digestion -Cholecystokinin (CCK) -->Stimulates the release of: ----->Bile from the gallbladder ----->Lipase from the pancreas Triglycerides -Monoglycerides -Free fatty acids Phospholipids -Glycerol -Free fatty acids Sterols -Absorbed as is
Lipids: Recommended Fat intakes: AMDR Dietary Guidelines vs American fat intakes:
RECOMMENDED: AMDR -20-35% total kcal Dietary Guidelines -< 10% kcals from saturated fats -Avoid trans fat -Limit dietary cholesterol ** American: Abundant in fat -Saturated > MUFAs & PUFAs Omega-6 Omega-3
Insulin
Released after eating, when blood glucose levels are high Promotes increased: -Glucose uptake by cells -Use of glucose as energy -Storage of excess glucose asglycogen -Lowers blood glucose levels
Glucagon
Released if no dietary carbohydrates are present,blood glucose levels have fallen Promotes increased: -Breakdown of glycogen -Gluconeogenesis -Blood glucose levels return to normal Epinephrine and norepinephrine also trigger gluconeogenesis Cortisol and growth hormone decrease amount of glucose used by muscle cells
alcohol digestion
Remember there is no digestion- Alcohol molecules are already small enough to be directly absorbed.*
High sugar diets:
Replace with intake of more nutritious foods Special concern for children and adolescents Increased risk of weight gain and obesity due to extra energy intake Increased risk of cardiovascular disease Increased levels of triglycerides and LDL - cholesterol, decreased levels of HDL-cholesterol Development of dental caries Bacteria in the mouth metabolize sugars into acids Acids dissolve tooth enamel
Fatty acids Saturated Unsaturated - monounsaturated, polyunsaturated
Saturated: Food sources: Meat Animal fat/butter Cheese Coconut oil Processed foods Unsaturated: Monounsaturated Food sources: Olive oil Peanut butter Avocado Almonds Pecans Polyunsaturated Food sources: Corn oil Soybean oil Sunflower oil Wheat germ Walnuts Pumpkin seeds
alcohol: Standard drink Moderate intake Digestion Absorption
Standard drink = 14 g alcohol -Beer: 12 oz -Wine: 5 oz -Hard liquor: 1.5 oz Moderate intake -1 drink per day for women and 2 drinks for men per day Digestion - none Absorption - simple diffusion
Polysaccharides
Storage form of glucose in plants Amylose-Unbranched chain of glucose molecules Amylopectin- Highly-branched chain of glucose molecules, mostly alpha bonds -More branches, more sites for enzyme action -Faster increase in blood glucose levels, glycogen Glycogen -Storage form of carbohydrate in humans and animals -Linked by alpha bonds -More highly-branched than amylopectin -Mainly stored in liver and muscle cells
Regulation of Blood Glucose
The liver and the pancreas are important in blood glucose control Liver determines amount of glucose that is needed to enter the bloodstream after a meal Stored as glycogen for later use Pancreas secretes: -Insulin -Glucagon
Indigestible Polysaccharides: Dietary and Functional Fiber
Total fiber -Found in many of the same foods as starch -Highly processed grains are low in fiber Cellulose, hemicellulose, pectins, gums, and mucilages -Lignins are only non-carbohydrate components of dietary fibers Linked together by beta bonds (largely undigestible) -Pass into the large intestine where bacteria: -Metabolize and form short-chain fatty acids and gas Insoluble fibers -Structural part of the plant cell -Cellulose, hemicellulose, lignins -Seeds, whole grains Soluble fibers -Found inside and around plantCells -Pectins, gums, mucilages, and some hemicelluloses -Oat bran, skins and flesh of fruits and berries; thickeners in jams, yogurts, sauces, and fillings; seaweed and psyllium
Type 1 diabetes typically, associated with, treatment
Typically: -Diagnosed in childhood -Runs in families -Caused by autoimmune disorder that destroys insulin- producing cells Associated with: -Decreased release of insulin -Increased blood glucose levels -Glucose in urine Treatment: -Insulin therapy -Nutrition therapy --3 regular meals and snacks --Individualized plan for carbohydrate, protein, and fat intake --Low intake of saturated fats and cholesterol --Carbohydrate counting and diabetic exchange system are useful
fatty acids(saturated, unsaturated)
a main source of energy -Component of triglycerides, phospholipids Chain of carbon & hydrogen atoms PLUS: -Carboxyl (acid) group -Methyl (Omega) group Building block of lipids Chain length Long ≥ 12 carbons Medium 6-10 carbons Short < 6 carbons
Gestational diabetes occurs during...
during Pregnancy -Typically resolves after pregnancy, but leads to higher risk of developing Type 2 diabetes
4 main Categories of Lipids
fatty acids, triglycerides, sterols, phospholipids
Marasmus
protein and energy deficiency
Kwashiorkor
protein deficiency
Triglycerides Most common type of lipid in food and body Composition Functions
the most abundant lipid in our diet and storage form of fat in our bodies Most common type of lipid in food and body -95% of food lipids we eat -95% of fat stored in body Composition -3 fatty acids -Glycerol backbone -Carboxyl end Functions -Energy -Insulation -Subcutaneous fat -Fat soluble vitamins -Storage -Adipose tissue
phospholipids functions
the primary lipid in cell membranes Functions: 1. Emulsifier -A compound that can suspend fat in water by creating a shell around a fat droplet -In the body and in food Examples -Mayonnaise --->Egg yolk has phospholipids, emulsifies oil in vinegar -Bile 2. Cell Membranes
Carbohydrates
Includes sugar, starch, and fiber Plants are main source Produce glucose during photosynthesis