NAME: DATE: MODULE 4 4.1 Scientific Inquiry Tied to Genetics, Evolution, and Obesity Scientific Inquiry The field of nutrition is based on study that integrates biology, physiology, microbiology, botany, chemistry, genetics and biology. In order to understand how is produced, it is crucial to understand the basics of inquiry. The Scientific Method Is hypothesis driven Follows a basic format Research Designs Ask a question (define the problem) Form a Design an Collect, analyze & interpret the data Generalize & publish the Ask another question (the generally leads to more questions) Clinical studies Laboratory experiments Testimonials are NOT based on research Study Types Case: Results from a single person protocol conducted by a medical doctor. Clinical: l design with a group of people. Epidemiological & Intervention: Population based, retrospective or. Laboratory: Experimental design with any life form;, virus, animals, plants, cell lines, bugs, etc.
Experimental Design things to 1. Number of Subjects: is there enough for statistical significance. 2. Duration of the Study: is it long enough for to be made. 3. Matching Groups: Ethnicity, gender, age, lifestyle, disease. 4. Control Groups: experimental vs placebo. 5. Reproducible Results: can the be repeated and yield the same results. 6. The Treatment Protocol: blind, blind, crossover. Treatment Protocol Blind: the subject does not know if they are in the or control group. Double Blind: the subject and the primary investigator do not know who is in the experimental or control group. Cross over: each group a period of being on the placebo and experimental drug. A highly reputable study design is called the cross over experiment. Public Recommends Consistent results from multiple studies published over many years are used to make dietary recommendations. A whole body of evidence, collected over many years of experimentation is by the scientific community to create public recommendations regarding diet and health (disease prevention). Obesity: An Epidemic Obesity is body fatness in excess of the level that is consistent with optimal health. There has been an rise in obesity in the United States over the last 20 years. Obesity is defined by Why is Obesity of Concern? Increased risk for chronic diseases and Increased risk for medical conditions Type 2 diabetes Type 2 diabetes is becoming more in obese adults & children. Obese children are more likely to become obese adults. The onset of Type 2 diabetes is preventable by diet, exercise & a good control program. Type 2 diabetes Heart disease & Liver/gallbladder disease Arthritis High-risk Hernia & Varicose veins Accidents Depression & Low self esteem High blood pressure (hypertension) High blood cholesterol and triglycerides High blood Overall obesity leads to decreased longevity and quality of life
4.2 Energy Balance Principles of Energy Balance 1 pound fat = 3500 Calories stored. To lose body fat, a Calorie deficit needs to be To gain body weight, a Calorie needs to be created. Body weight changes are based on the relationship of Caloric (Energy) intake & Energy. Energy Balance Equations If Calories Consumed = Calories Expended Body weight is typically maintained. balance occurs. If Calories Consumed > Calories Expended Weight is typically. energy balance occurs. If Calories Consumed < Calories Expended Energy Intake Weight is typically. Negative energy balance occurs. Consumption of Energy Producing Nutrients in Food and Beverages Protein ( Calories per gram) Carbohydrate ( Calories per gram) Fat ( Calories per gram) Alcohol ( Calories per gram) All of the Calories add up! Energy Expenditure Basal Metabolic Rate (BMR)» An amount of energy needed to life Voluntary muscle» Calories burned in activity (PA) The specific action (SDA) of food (also called the thermic effect of food)» Energy required for food digestion & Basal Metabolic Rate (BMR): The energy by the body to minimally (heart to beat, lungs to breathe, ). It is in a fasting state (12 hours) and when the body is at complete rest.
Majority of in a sedentary person. Resting Energy Expenditure (REE): Is similar to BMR. It considers the amount of energy by a person at rest. REE can be measured in the lab or using the Mifflin Equations. The Mifflin Equations REE Formula For WOMEN: REE (Calories/day) = (10 x W) + (6.25 x H) (5 x A) - 161 REE Formula For MEN: REE (Calories/day) = (10 x W) + (6.25 x H) (5 x A) + 5 W= Weight in Kg (pounds divided by 2.2) H = Height in centimeters (inches x 2.54) A= Age in years Factors Affecting BMR/REE Age: BMR is reduced with age. Gender: More lean mass means a higher BMR (gender ). Physiological State: Illness, pregnancy, lactation, stress, metabolic diseases like can increase the BMR. Starvation or prolonged fasting decreases BMR up to 80% in women & 60% in men. Environmental Temperature: Hot or cold temperatures increase BMR. Energy Expenditure Physical Activity (PA): The energy expended to perform physical activity. Voluntary muscle movement. The total amount of energy expended with body weight and the intensity of the exercise.
Physical Activity & Calorie Burn The BMR or REE can be used to energy spent or Calorie burn in PA. Calories burned = Hours spent in activity x REE x Activity Factor 24 hours/day. Activity factors Energy Expenditure Sleeping/Reclining: Factor of 1 Very Light Activity: sitting or standing in a small space: Factor of 1.5 Light Activity: moving without sweating: Factor of 2.5 Moderate Activity: moving and sweating: Factor of 5.0 Strenuous Activity: all out efforts that cannot be sustained for more than a few minutes without exhaustion: Factor of 7.0 Specific Dynamic Action (SDA): The food processing. Also called the thermic effect of food. ~10% of the total number of Calories is required for the digestion, absorption & assimilation of nutrients into the body. Metabolism is increased when fed. 4.3 Body Composition and Weight Control Body Composition Determination of body weight should be based upon body. It is important to know the % of total body weight that is fat. Values should be considered for good health, personal appearance, & performance reasons Healthy Body Composition Lean body mass ~55% of total body weight (muscle is ~70% H 20) Essential fat mass 3% body fat in 12% body fat in Stored fat mass is variable ~ 15-20% (Additional fat beyond essential fat is stored) Minerals ~4% of total body weight Water ~ 60% of total body weight Body Weight vs. Body Fat The best way to determine obesity is to the % of body fat. is too fat if 20% body fat. is too fat if 26% body fat.
Determining Body Fat The scale doesn't accurately tell body fat Underwater (very accurate) Bod (very accurate) Skin fold (the more sights, the better) Bioelectrical impedance (the persons hydration level affects the reading accuracy) Futrex 5000 (more accurate when body fat) Research Techniques (DEXA, MRI, total body potassium, substance dilution) Fat Distribution Gut vs. Butt Central adiposity (obesity) has health risks: Type 2 diabetes High blood cholesterol Heart disease Central Adiposity Android Obesity & Apple Shape Determined by waist measurement. waist measurement > 40 inches = central adiposity & apple shape. waist measurement > 35 inches = central adiposity & apple shape. Gynoid Obesity Pear Shape Pear shape is determined by a large hip t. Subcutaneous fat accumulates around the hips. Is not as detrimental to health as visceral fat in the abdominal cavity. Body Mass Index (BMI) Indicates the healthiness of body weight in relation to height. Is not an accurate measure of % body. A BMI 25 and a waist circumference of >40 inches for men or >35 inches for women places an individual at increased risk for: Heart disease,, Dyslipidemia, & Type 2 diabetes.
Calculating BMI BMI = Weight (Kg) Height (M) 2 Conversions: Kg = Pounds 2.2 M = Inches 39.37 Do not forget to square the height in meters or your math will indicate obesity! Sample Calculation John weighs 182 pounds and is 68 inches tall, What is his BMI? 182lb 2.2 = 82.73Kg 68 inches 39.37 = 1.73 Meters 1.73 2 meters = 2.99 Meters squared (M 2 could also be calculated as 1.73 x 1.73 = 2.99 Meters squared) John s BMI = 82.73 Kg = 27.7 2.99 M 2 People with high LBM may have a high BMI but are not obese. It is a good idea to determine body on all individuals who have a BMI that is 25 to confirm obesity. Interpreting BMI BMI Risk <18.5 Underweight 18.5-24.9 Normal 25-29.9 Overweight 30-34.9 Class I Obesity 35-39.9 Class II Obesity 40 Extreme Obesity Combating Obesity Surgery: Lipo-suction Drugs: Gastric bypass Over the counter & prescribed
These methods can be health threatening & usually do not result in long-term sustained weight loss and/or a healthy lifestyle Combating Obesity Diets: Low carb &/or very low Calorie There is 6% success rate for reducing weight and the weight loss by dieting. During prolonged fasting (or low calorie, low carb diets), the BMR declines and lean body mass is used to make glucose for brain, central nervous system, and red blood cell functioning. The body chemistry changes under conditions of Feasting & Fasting Weight Control When considering weight loss, it is important to lose the fat weight and preserve the lean body mass or muscle. The reason for weight loss should be to excess of body fat. Fat weight loss is a slow process. Effective Weight Loss Optimal weight loss rate is 1 lb/week. 1 lb of fat weight loss requires a 3500 Calorie deficit. A 500 Calorie deficit per day times 7 days per week a rate of weight loss of 1 lb/week. 500 Calorie Deficit/Day 40 minutes exercise = 300 Calories (preserves LBM, BMR and utilizes stored fat) 22g of dietary fat removed from the diet = 200 Calories. Results in: 1 pound per week of body fat lost. Preservation of lean body mass. A faster rate of weight loss forces the body to use protein to meet the glucose/energy needs of the body. Benefits of Exercise It promotes fitness Higher HDL levels Lower resting heart rate Lower blood More LBM Flexibility, strength & Healthy body weight
Better mental outlook The DRI for PA is 60 minutes moderate activity per day Burning 2000-3000 Calories per week reduces disease Over exercising one area of the body does not result in spot reduction Making the Changes Incorporating the dietary changes and the exercise behaviors permanently into the lifestyle requires a step process. A progressive behavior program can facilitate successful lifestyle changes. Behavior Modification Identify goal (realistic). Identify current behaviors that need to change. Identify behaviors that will achieve the goal & reinforce them. Commit to change. Plan (set realistic small changes into action, rewards). Persist long enough to see results, reinforces. Evaluate the progress & modify the plan Life Long Diet Protocols Greater long term success rates with: 1. Eating a well-balanced diet from a variety of foods to achieve nutrient adequacy. 2. an hour-long exercise program daily. 3. Using behavior modification to permanently incorporate health behaviors What is Nutritional Adequacy? The diet provides: Essential Fiber Energy health. When should it be considered? Nutritional adequacy should be for each individual diet. In weight loss, weight maintenance or gain diets, nutritional adequacy should also be considered.
How is it measured? Dietary assessment tools like: Diet Analysis software Food Composition tables & The Exchange System Used to prescribe & monitor dietary. How is it interpreted? All diets (especially weight control diets) need to be planned so that there are no inadequacies, deficiencies, or risks for toxicity. Inadequate Intake: < 100% of the DRI Deficient Intake: < 66% of the DRI Risk of Toxicity: > 100% of the UL Applies to all nutrients with and/or What other factors should be considered? The diet should be planned to promote health by limiting: Saturated & Trans fatty acids, cholesterol, simple sugar, &. Plan intake of Calories from carbs, protein, and fat to meet. 4.4 Principles of Fitness for Health Total Fitness for Health Fitness is health! It has been document that who are physical fit have far less mortality and as compared to their sedentary counterparts. What does being fit mean? What are the health benefits of exercise?
The Values of Exercise Exercise Value General Health Specific areas of benefit Improved mental health Increased feeling of vigor Improved sleep pattern Increased bone density Decreased risk of chronic diseases such as cancer, heart disease, diabetes, arthritis, and vascular diseases Body Composition and Weight Control Decreased percent body fat Increased lean body mass Stabilized body weight Increased metabolic rate Improved muscle tone Cardio-Respiratory Health and Fitness Improved circulation (pumping capacity of the heart, stroke volume, oxygen delivery capacity to the tissues, and promotion of wound healing, decreased tendency for infections) Increased oxygen uptake Improved lipid profile, decreased total cholesterol (increased HDL, decreased LDL), decreased triglycerides Decreased blood pressure Decreased heart rate Increased efficiency of metabolic processes (fat metabolism and carbohydrate metabolism) Athletic Performance Improve competitiveness in sporting events Body Sculpting
Fitness Testing The score from the elements of evaluating: Aerobic capacity Muscular Muscular Flexibility Body A high overall score is associated with health and longevity Developing a Total Fitness Program A safe and effective fitness program to perform well in Physical Fitness testing and reduce the risk of injury includes a: Warm-up Aerobic exercise Flexibility exercise Cool- Aerobic & Resistive Exercise Aerobic exercise demands a higher functioning level of the cardio-respiratory systems The capacity is reflected by VO 2max Resistive exercise demands a higher level of the skeletal- systems Aerobic Exercise The capacities are displayed through measures of muscular strength and muscular endurance Physical activity where the heart rate can be elevated and maintained for at least ten minutes and there is increased oxygen uptake and delivery to the body and muscles A few examples include walking, jogging, cycling, swimming, and cross country The three that affect aerobic capacity are frequency, intensity and duration of the exercise The FIT Classification System You can use: F-frequency (times per week)
I- intensity (percent of maximum heart rate, %MHR) T-time (the number of minutes that the heart rate is maintained To classify your level of competency by the following table: Resistive Exercise One can improve muscular strength or endurance by determining first, the one-repetition maximum and then adjusting the amount of: Resistance (the amount of opposing weight during the muscle, strength train at 80% of the one-rep-max) The number of of the muscular contraction and the number of sets completed Speed of the muscle contraction 3-4 sets of 8-12 reps twice a week to maintain strength and three times a week to gain. There are many ways to contract a muscle and affect muscle strength Muscle Contractions, Training Types, and Balanced Lifts Muscle Contractions Training Types Balance Lifts Eccentric Muscle Contraction Muscle is elongating while contracting or generating tension Concentric Muscle Contraction Muscle is shortening while contracting or generating tension Isometric Muscle Contraction Static muscle length while muscle generates tension. This type of contraction is uses when joints are injured to attempt to maintain some muscle strength. Isometric Training Program involves a series of isometric muscle contractions. Isokinetic Training The use of special equipment to control the speed of the muscle contractions. Circuit Training Combines aerobic activity with resistive activity for the purposes of increasing calorie burn, reducing boredom and improving fitness. Weight Training Program involves lifting weights. Bench press/seated row Dumbbell bench press/ bent-over row Shoulder press/lateral pulls Seated leg press/truck flex Pectoral fly/bent-over fly Upright row/dips Lateral raises/medial pulls Leg extension/leg curls Bicep curl/tricep extension
The Overload Principle The Overload Principle involves applying a greater work load than on the cardio-respiratory or skeletal-muscular systems that leads to increased functional capacity For aerobic capacity, one must work at least at 70%MHR For muscular, one must lift at least at 80% of the 1-rep-max (3 sets of 8-12 reps) Logging Activity for Weight Control and Health An exercise volume that has been associated with the risk of chronic disease is burning between 2,000-3,000 Calories per week in 30-45 minutes of moderate exercise, 3-5 times per week promotes weight loss. 60 minutes of rigorous activity per day is needed to lose weight, keep the weight off, and improve capacity. Logging Activity for Health You can use the following activity log to evaluate your exercise for; Total fitness format Aerobic exercise Flexibility Cool-down Calorie burn of Time x factor x REE 24
Exercise Activity Log
4.5 Fundamentals of Exercise for Nutrition Fuel Utilization During Exercise ATP production is from carbohydrate and fat As the intensity of the exercise increases, the of carbohydrates used to produce ATP increases Nutrition supplies the or fuel (carbohydrate, fat and protein) and the essential structural components of enzymes (cofactors) needed to drive chemical reactions to generate ATP through: Glycolysis The citric acid cycle The electron transport chain. ATP energy production through glycolysis, the citric acid cycle, and the electron transport chain
Carbohydrates The objectives of dietary carbohydrate management is to blood sugar and replete muscle glycogen Carbohydrate as fuel supports high exercise Carbohydrate are in the body Carbohydrates in the Body and Diet Blood Glucose 4.5 grams of glucose total Constantly used by RBC and CNS Liver Glycogen 75 (to 100) grams when Used to maintain blood Muscle Glycogen Amount of exercise and dietary intake determines the amount Used to produce ATP in the muscle during exercise Carbohydrate Management for Enhanced Exercise Performance Diet and exercise influence glycogen stores in the muscle. High intake (7-10 gm/kg/day) 60-65% of Calories from carbohydrate The timing of the carbohydrate intake in relation to exercise is important: Prior to the Exercise (4 hours before or 2 hours before and 5-10 minutes before) During the Exercise (about every 15 or 20 minutes) After the Exercise ( after and again 2-6 hours later) Recovery Nutrition after Exercise Muscle glycogen repletion begins immediately after the exercise and prepares the stores for the next workout! Consuming meals that provide the of carbohydrate and protein at a three gram to one gram ratio promotes muscle glycogen repletion
Proteins Athletes require more protein to stay in nitrogen balance as to individuals who are meeting their DRI for physical activity The range is 1.2 to 1.6 grams of protein per kilogram of body To support lean body mass, a strenuous weight-lifting program, 1.6 grams of protein per kilogram of body weight and a positive energy balance of 200 Calories is needed High quality or the equivalent is needed for 2/3 of the protein consumed The dietary fat s made to the athlete are the same that support health and meet the DRIs Consume low-fat foods prior to exercise and a low-fat (20-25% of Calories) diet in Adding MUFAs may be the best choice of fats if weight gain is MCT have been touted to be useful during exercise, but not proven, however, they are useful for syndromes due to their direct absorption into the blood Thermal Regulation and Hydration The ability to keep the body cooled during exercise is key to exercise and avoiding injury. A lot of heat is in the body due to the inefficiencies of energy transfer to make ATP. Sweating creates the evaporative cooling system employed during exercise to keep the core body in a functional range. Understanding and Controlling Body Temperature The core body temperature rises during exercise If the core body temperature >104 o F, exercise capacity and risk of thermal injury increases Fluid, salt, and other components are lost in sweat during about a liter of fluid per hour of exercise, and 2.6 grams of salt per liter Salt (NaCl) is 40% sodium, ½ t salt replaces the sodium lost in 1 hour of exercise
Dehydration to Hydration The fluid lost in sweat comes from the blood The plasma volume is the fluid for sweat This is why there is such large in aerobic exercise capacity due to dehydration The sensation of thirst signifies 2% dehydration, cardiovascular and aerobic is reduced. 5% dehydration, serious injury risk. The body can absorb 1 liter of fluid per hour. Replacing fluids (cool, dilute, small, and frequent amounts) during exercise is important: Hydration Happy and Dehydration Demise 1 cup at 41 o F, every 10-15 minutes Drink without thirst to avoid Importance of hydration during exercise Cardiovascular demise during dehydration Optimize muscle strength Plasma volume decreases Optimize aerobic capacity Osmolarity of the blood increases Prevention of thermal injury which include dizziness, cramping, fainting, heat exhaustion and heat stroke Blood pressure goes down. Constriction of the blood vessels Pool of fluid to draw upon for sweat loss is the blood stream. Increase in heart rate Decrease in heart filling The cardiovascular system is affected dramatically by fluid losses. Decrease in cardiac output Decreased sweating Increase in core body temperature