Energy Balance, Body Composition, Weight Management (Module 8) PDF

Module 8 Energy Balance, Body Composition and Weight Management Chapter 7 1  Energy Balance 1 kg = _________ lbs 1 gram of fat = _______ kcal 1 lb = 454 grams 454g x 9 kcal = 4086 kcal fat cells (adipocytes) in the body contain more than fa...

Module 8 Energy Balance, Body Composition and Weight Management Chapter 7 1  Energy Balance 1 kg = _________ lbs 1 gram of fat = _______ kcal 1 lb = 454 grams 454g x 9 kcal = 4086 kcal fat cells (adipocytes) in the body contain more than fat: 1.) 87% fat (454 x.87 = 395 kcal x 9 = 3555 kcal), **1 lb body fat = 3500 kcal** 2.) other constituents: water, protein 2 Adipocytes in the body contain droplets of fat surrounded by other cell components.  Weight Loss TO LOSE ONE POUND/WEEK: - EAT 500 kcal less every day - EXERCISE to use up 500 kcal every day * COMBINATION OF DIET (Less 250 kcal) AND EXERCISE (use up 250 kcal) (500 kcal X 7 days = 3500 kcal/week) 4  Weight Loss SAFE weight loss: 1 - 2 lbs/week (0.5 - 1.0 kg/week) - 10% of body weight in 6 months AMOUNT OF WEIGHT YOU LOSE WILL DEPEND ON YOUR BODY WEIGHT 5 ENERGY BALANCE: What you weigh is a balance between how much energy you consume and how much energy you expend. Energy In = Energy Out, you maintain your body weight (mass). Energy IN Energy OUT Energy In > Energy Out Energy In < Energy Out 7 Measuring the Energy in Foods: Bomb Calorimeter An instrument used to determine the energy (kcal) content of food. -A bomb calorimeter measures the heat energy released when a dried food is combusted. -When food burns, energy is released in the form of heat. (because bonds break and H2O and CO2 are released) -The amount of heat given off provides a DIRECT measure of the food’s energy value. -Remember, that kcal are units of heat energy 8  Food Intake (definitions) Appetite: refers to the sensations of hunger, satiation, and satiety that prompt a person to eat or not eat Hunger: the physiological response to a need for food triggered by chemical messengers acting in the brain, primarily the hypothalamus Satiation: the feeling of satisfaction and fullness that occurs DURING a meal and stops eating (determines how much food is consumed during a meal) Satiety: the feeling of satisfaction and fullness AFTER eating, (determines how much time passes between meals) 9  ENERGY OUT: Determination of Daily Caloric Needs 10  ENERGY OUT: Determination of Daily Caloric Needs 1. Basal Metabolic Rate (BMR) 2. Resting Metabolic Rate (RMR) 3. Thermic Effect of Food (TEF) 4. Exercise Metabolic Rate (EMR) 11  BASAL METABOLIC RATE - Energy required for essential physiological function - The rate of energy expenditure under resting conditions. - It is measured after 12 hours without food or exercise. kcal required for BMR: - Males: 24 x body weight (kg) - Females: 23 x body weight (kg) 12  BMR BMR decreases by about 2-5% per decade after growth has stopped (this is why we require less kcal as we get older) -this may be less if you remain active and maintain lean body mass - BMR is lowest at rest - EXERCISE increases BMR - BMR stays elevated for about 30 minutes following exercise (depending on the intensity of exercise) - intense/strenuous exercise can keep BMR elevated for several hours following exercise 13  RESTING METABOLIC RATE Energy required for normal daily sedentary activities Walking, sitting, standing Approx 30% above BMR BMR and RMR are often considered together as BMR only or RMR only 14  Factors affecting BMR/RMR Variable  or  Increasing body temp (fever) Environmental temperature: Heat Environmental temperature: Cold Stress (epinephrine) Body Composition: FFM (muscle) Body Composition: fat mass (body fat) Body Surface Area: Increase in Height Body Surface Area: Increasing Body Weight  Factors affecting BMR/RMR (cont’d) Physical Activity Herbal Supplements (ephedrine) Thyroxin production (T4) released from thyroid gland Hormones (leptin) Nicotine Caffeine Growth (children, pregnancy) Aging Fasting, low kcal diets, starvation  Thermic Effect of Food (TEF) or Diet Induced Thermogenesis The energy required to digest, absorb, transport, metabolize, and store ingested nutrients This increase in energy expenditure causes body temperature to rise slightly for several hours after eating. The TEF reaches a maximum within one hour after a meal The TEF will vary depending on both the quantity and type of food eaten 17  Thermic Effect of Food CHO 6 – 8% Fat: 2 - 3% Protein: 15 - 30% Alcohol: 15 – 20% Average: 10% for TEF 18  Exercise Metabolic Rate (EMR) kcal required for physical activity Many methods for calculated energy expenditure during exercise 19  Intensity of Different Activities Canadian Guidelines MVPA 150 min/week 20 Calculating kcal expended during exercise based on body weight  Calculate the Total Energy Requirement for the Following Individual using BMR, RMR, TEF, EMR Gender: Male Weight: 187 lbs Exercise: Running 5mph for 30 minutes is 0.061 kcal/lb/min 22 Calculating Total Daily Energy Requirements using the Equation Developed by the DRI Committee 23  Estimated Energy Requirements (EER) Males (19 and older) EER = 662 – 9.53 x age + PA x [(15.91 x wt) + (539.6 x ht)] Females (19 and older) EER = 354 – 6.91 x age + PA x [(9.36 x wt) + (726 x ht)] Weight – kg Height – metres PA – physical activity factor See next slide 24 25  Calculate the EER for the following individual Gender: Female Age: 22 Height: 5 ft 6 in Weight: 132 lb Physical Activity: Low active Females (19 and older) EER = 354 – 6.91 x age + PA x [(9.36 x wt) + (726 x ht)] 26  Question for energy expenditure How many weeks would it take a 75 kg man to lose 5 lbs if he walks 3.5 mph, 5 days/week for 30 minutes, and he burns 0.104 kcal/min/kg? 27  Question for Energy Expenditure A person is performing domestic activity for 30 minutes/day. The energy expenditure of this activity is 0.048 kcal/min/kg and the person weighs 65 kg. At this rate of energy expenditure, how many days would it take to expend the equivalent of 10 lbs of body fat? 28  Question for Energy Expenditure An 80 kg person rakes leaves for 4.5 hours. The rate of energy expenditure is 0.091 kcal/min/kg. Calculate the energy expenditure for this activity. 29 Defining a Healthy Body Weight: Underweight, Overweight, and Obesity - Height/Weight Tables - BMI - % body fat - body shape - body fat distribution - waist hip ratio - waist circumference 30 Body Mass Index (BMI): WHO classification Classification BMI (kg/m2) Risk of Comorbidities Underweight < 18.5 Low (but risk of other clinical problems increased) Normal Range 18.5 – 24.9 Average Overweight 25.0 – 29.9 Average to (pre-obese) Moderate Class I Obesity 30.0 – 34.9 Moderate Class II Obesity 35.0 – 39.9 Severe Class III Obesity > 40 Very Severe 31  Mortality 15 Risk increases as BMI declines 25 20 30 Body mass index BMI and Mortality 40 35 Risk increases as BMI rises  BMI = Weight (kg)  (Height (m))2 1 kg = 2.2 lbs 1 inch = 2.54 cm Example: Female, 150 lbs, 5 ft 6 in 150/2.2 = 68.18 kg 66 inches x 2.54 = 167.64 = 1.6764 m BMI = 68.18/(1.6764)2 = 68.18/2.8103 = 24.26 = 24.3 33 Determine the BMI for the following individual: Gender: Male Age: 24 Body weight: 180 lbs Height: 5 feet 11 inches 34 Defining a Healthy Body Weight : Methods Used to Assess Body Fat Fatfold measures Hydrodensitometry Bioelectrical impedance Air displacement Dual energy X-ray plethysmography absorptiometry (DEXA) MRI Body Shape: Body Fat Distribution Subcutaneous fat Intra-abdominal fat or Visceral fat Intramuscular fat Intramyocellular Lipids (IMCL) – Lipids stored within the muscles cell Extramyocellular lipids (EMCL) – Lipids located between muscle fibres Intramuscular fat 36 Body Shape “Apple” and “Pear” Body Shapes Compared Apple Obesity: Android (Manlike) obesity Pear Obesity: Gynoid (womanlike) obesity Obesity: Waist Girth 102cm > males 88cm > females Location of Body Fat 38 Weight Management - overweight/obesity - underweight 39  Overweight and Obese (BMI) Canadian Adults 2021 45 40 39.2 36.6 36.5 35 32.8 33.4 30.8 29.1 Overweight Percentage 30 Obese 25 22.2 20 15 10 5 0 18 to 34 35 to 49 50 to 64 65 and over Blue: Overweight Red: Obese Source: Statistics Canada, Canadian Community Health Survey (CCHS), 2022 Body mass index, overweight or obese, self-reported, adult, age groups (18 years and older) (statcan.gc.ca) 40 40  Health Problems Associated With Obesity Metabolic Type 2 Diabetes Cardiovascular Disease Syndrome Heart Attack Insulin resistance Stroke Hyperglycemia High BP IGT Dyslipidemia (High Hyperinsulinemia LDL, TG, low HDL) Obesity Cancers Gout (colon, breast, Endometrial) Gallbladder Disease Sleep apnea and Respiratory problems Bone and Joint Problems 41 42 Excess Body Weight/Fat and Disease Risk Among Canadians 43  Causes of Obesity Energy In > Energy Out – Fat cell development – Increased kcal – Portion sizes – Inactivity – TV watching Fat Cell Metabolism - thyroid function, LPL Set Point Theory Genetics: Leptin, Ghrelin, Adiponectin 44  Fat cell development Energy in > Energy out The amount of fat on a person’s body reflects both the number and the size of the fat cells. Hyperplastic obesity – obesity due to an increase in the number of fat cells Hypertrophic obesity – obesity due to an increase in the size of fat cells 45 Fat Cell Development  Obesity may be attributed to the over- consumption of energy (kcal) BMI has been steadily increasing over the years Energy Intake has also been increasing Physical Activity has not changed 47 Lifestyle and Rising Obesity Rates 48 Regardless of hunger, people typically overeat when offered the abundance and variety of an “all you can eat” buffet. 49 Other Possible Causes of Obesity 50  Fat Cell Metabolism: Thyroid Function may naturally have a low BMR (due to hypothyroidism or other metabolic diseases) Thyroid gland – produces the hormones: i) T4 - thyroxin ii) T3 - triiodothyronine 1.) Increase the rate of metabolism 2.) Regulate protein, fat, CHO catabolism 51  Fat Cell Metabolism - LPL LPL – lipoprotein lipase, an enzyme mounted on the surface of fat cells LPL promotes fat storage in both fat and muscle cells Takes the TG from passing lipoproteins, hydrolyzes them, and passes the fatty acids into the cell People with high LPL activity are efficient at storing fat Obese people have much more LPL activity in their fat cells than lean people 52  Fat Cell Metabolism – LPL (cont’d) LPL activity is partially regulated by sex hormones ________________________ in women ________________________ in men In women, fat cells in the breasts, hips, and thighs produce abundant LPL, putting fat in those body sites In men, fat cells in the abdomen produce abundant LPL This may explain why men tend to develop central obesity whereas women more readily develop lower body fat 53  LPL Research – found that LPL levels increased when weight was being lost, And, that LPL levels increased most in obese individuals after weight loss Researchers theorize that weight loss serves as a signal to increase LPL activity or increase production of LPL This may explain why obese people easily regain weight after having lost it 54  Set Point Theory The body tends to maintain a certain weight by means of its own internal controls. The body adjusts its metabolism whenever it gains or loses weight 55  Obesity Causes: Genetics 2 parents obese – child has an 80% of becoming obese  Obesity Causes: Genetics 1 parent obese – child has about 50% of becoming obese  Obesity Causes - Genetics O parents obese: - child has 10% chance of becoming obese  Causes of Obesity – Genes - Leptin Thought of as the “anti-obesity” hormone “leptin” (Greek word (lepto) – thin) Protein that is a product of the obesity (ob) gene Produced by adipocytes (fat cells) and acts in the hypothalamus The amount of leptin produced is proportional to the size of the adipocytes: more leptin is released as fat stores increase 59  Causes of Obesity – Leptin Leptin exerts its effect on food intake and energy expenditure by binding to leptin receptors in the hypothalamus Leptin inhibits hypothalamus peptides such as neuropeptide Y (NPY increases appetite and stimulates lipogenesis, therefore storing fat) 60  Leptin’s Action in the Body Changes in the size of adipocytes affect the amount of leptin released. The amount of leptin reaching the hypothalamus determines the response and helps return body fat stores to a set level. Leptin Resistance: Most obese people have high levels of leptin, but their energy balance does not automatically shift to the negative, suggesting a resistance to leptin’s action in obesity. Mice Without and With Leptin Compared Both mice have a defective ob gene. Consequently, they do not produce leptin. They both became obese, but the one on the right received daily injections of leptin, which suppressed food intake and increased energy expenditure, resulting in weight loss. In obese adult humans, leptin injections were ineffective.  Obesity: Gut Peptides There are many gut peptides that have been identified as regulating food intake. The peptides that have received the most research attention are: 1. Cholecystokinin (CCK) 2. Peptide tyrosine tyrosine (PYY) 3. Ghrelin 4. Glucagon-like peptide-1 (GLP-1) 63  Obesity: Gut Peptides 1. Cholecystokinin (CCK): suppresses food intake dietary protein and fat in the SI stimulate the release of CCK, which binds to receptors on nerves, that send a signal to the hypothalamus to reduce food intake. 2. Peptide tyrosine tyrosine (PYY): suppresses food intake Released by the SI after eating and acts on the hypothalamus to decrease appetite Research suggests that obese individuals need to eat more kcal to release the same 64  Obesity: Gut Peptides 3. Ghrelin: stimulates food intake protein produced by stomach cells stimulates growth hormone release increases hunger and food intake suppresses fat utilization in adipose tissue 65 Blood concentrations of ghrelin are lowest shortly after consumption of a meal, then rise during the fast just prior to the next meal.  Obesity: Gut Peptides: Ghrelin Dieters who lose weight and then try to keep it off make more ghrelin than they did before dieting, as if their bodies are fighting to regain the lost fat By contrast, very obese people who have gastric bypass surgery to lose weight, end up with very little ghrelin, which may help explain why their appetites decrease after the surgery. 67  Obesity: Gut Peptides 4. Glucagon-like peptide-1 (GLP-1) or GLP-1 agonists GLP-1 agonists activate the GLP-1 receptor. GLP-1 is a gut hormone that binds to the GLP-1 receptors located in the pancreas and gut Treatment for Diabetes: Inhibit the release of glucagon and stimulate insulin production to reduce blood glucose 68  Obesity Treatment and Prevention Diet and Exercise Drug therapy Surgery 69 Best for Weight Loss: diet and exercise Energy In (reduction kcal) and Energy Out (increase physical activity) Best for Weight Maintenance: diet and exercise Energy In (reduction kcal) and Energy Out (increase physical activity)  Obesity Treatment: Drug Therapy Semaglutide: Ozempic or Wegovy GLP-1 receptor agonist Approved for adults with Type 2 diabetes GLP-1 increases insulin production and decreases glucagon in the pancreas, which lowers blood glucose. GLP-1 delays gastric emptying (slows down digestion), reducing appetite, therefore used for weight loss Injection under the skin (subcutaneous injection) 71 Obesity Treatment: Drug Therapy Health Canada has approved Wegovy but not Ozempic for weight loss Both may be prescribed by physicians for weight loss Approximately $400/month Possible Side Effects: nausea, vomiting, heartburn, constipation, dizziness, fatigue 72 Gastric Surgery (Bariatric Surgery) Gastric Surgery (Bariatric Surgery)  Weight Loss Strategies Watch your serving size Cut down on high-kilocalorie foods – Reduce fat and sugary foods Don’t get too hungry – Eat breakfast, increase veggies, increase fibre If you want to eat more, engage in more physical activity 75  Diets, Diets, Everywhere Google Fad Diets, how many do you find? When searching the internet, you need to: Distinguish between a healthy diet and a fad diet. Describe the characteristics of a well-planned low kcalorie diet. Describe the advantages and disadvantages of prepared food diet plans. Describe the advantages and disadvantages of low-fat diets. Describe the advantages and disadvantages of low- carbohydrate diets. Assess the effectiveness of common weight-loss diets. 76  Evaluating Weight-Loss Programs Distinguish Between Healthy Diets and Fad Diets 77  Health Risks of Underweight Unable to preserve lean tissue (muscle) during sickness and/or disease Associated with osteoporosis and bone fractures Underweight females develop menstrual irregularities (amenorrhea), may become infertile, and give birth to unhealthy babies Eating Disorders Anorexia Nervosa Bulimia Nervosa Binge-Eating Disorder (BED) Eating disorder not otherwise specified 78 (EDNOS) 78  Eating Disorders Anorexia Nervosa - Most are females (males only account for 1 in 20 cases) - Distorted body image (overestimates fatness) - Amenorrhea, depressed, starving themselves Bulimia Nervosa - More common in females - Binge eating then purging (throwing up) - Underweight or normal weight - Bad teeth, ulcers Binge-Eating Disorder -consume less during a binge than bulimics -overweight or obese Eating disorder not otherwise specified A diagnostic category for eating disorders that fail to meet full criteria for either AN or BN (ie – AN without amenorrhea) (ie – an individual at a normal weight, does not binge, but self-induces vomiting after a normal size meal)79 79 Am I Perfect Yet? 80