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Energy Balance, Body Composition and Weight Management.

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Presentation on theme: "Energy Balance, Body Composition and Weight Management."— Presentation transcript:

1 Energy Balance, Body Composition and Weight Management

2 Energy Balance Definition: Definition: Calories IN = Calories OUT Calories IN = Calories OUT Positive energy balance Positive energy balance Energy intake > energy expended Energy intake > energy expended Results in weight gain Results in weight gain Negative energy balance Negative energy balance Energy intake < energy expended Energy intake < energy expended Results in weight loss Results in weight loss

3 Energy In: Food Intake: Physiological/Cognitive Influences Food Intake: Physiological/Cognitive Influences Physiological: Empty stomach, gastric contractions, GI hormones, absence of nutrients in small intestine hunger Physiological: Empty stomach, gastric contractions, GI hormones, absence of nutrients in small intestine hunger Satiation, satiety – gastric distention, GI hormones, feeling of satisfaction during/after eating stop eating Satiation, satiety – gastric distention, GI hormones, feeling of satisfaction during/after eating stop eating

4 Hunger, Satiation, and Satiety Physiological influences Satiety Cognitive influences Sensory influences Postabsorptive influences Postingestive influences Hunger Satiation Satiety 1 2 3 4 5

5 Liver Pancreas Fat Gastrointestinal tract Hypothalamus Glucose Insulin FFA Leptin Gut hormone

6 Modulators of feeding behavior Name Site of production Effect -melanocyte stimulating hormone ( -MSH) Hypothalamus Inhibition Agouti-related peptide (AGRP) Hypothalamus Stimulation Cocaine-amphetamine- regulated transcript (CART) Hypothalamus Inhibition Neuropeptide Y (NPY) Hypothalamus Stimulation Peptide YY (PYY) G-I tract Inhibition Ghrelin G-I tract Stimulation Insulin Pancreas Inhibition Leptin Adipose Inhibition

7 Energy Out The kcals the body expends: The kcals the body expends: Basal metabolism Basal metabolism Physical Activity Physical Activity Digestion, absorption, and processing of ingested nutrients (thermic effect of food) Digestion, absorption, and processing of ingested nutrients (thermic effect of food)

8 Components of Energy Expenditure Physical activities Thermic effect of food Basal metabolism

9 Basal Metabolism Supports the basic processes of life Supports the basic processes of life 60 – 70% of the total energy needs 60 – 70% of the total energy needs Amount of energy needed varies between individuals Amount of energy needed varies between individuals

10 Factors affecting Basal Metabolism Age Age Height Height Growth Growth Body Composition Body Composition Fever/Stress Fever/Stress Environmental temperature Environmental temperature Fasting/Starvation/Malnutrition Fasting/Starvation/Malnutrition Hormones Hormones

11 Energy for Physical Activity Most variable and changeable Most variable and changeable Significant in weight loss and weight gain Significant in weight loss and weight gain Voluntary Voluntary Increases energy expenditure beyond BMR by 25 – 40% Increases energy expenditure beyond BMR by 25 – 40%

12 Thermic Effect of Food (TEF) Energy used to digest, absorb, and metabolize nutrients Energy used to digest, absorb, and metabolize nutrients 6 – 10% above the total energy consumed 6 – 10% above the total energy consumed Protein 20-30% Protein 20-30% Carbohydrate 5-10% Carbohydrate 5-10% Fat 0-5% Fat 0-5%

13 Estimating Energy Requirements Gender – men generally have a higher BMR Gender – men generally have a higher BMR Growth – BMR is high in people who are growing Growth – BMR is high in people who are growing Age – BMR declines as lean body mass decreases Age – BMR declines as lean body mass decreases Physical Activity – Vary considerably Physical Activity – Vary considerably Body size and composition Body size and composition

14 Defining Healthy Body Weight Weight within suggested range for ht Weight within suggested range for ht Fat distribution pattern assoc with low risk of illness Fat distribution pattern assoc with low risk of illness Medical history with absence of risk factors Medical history with absence of risk factors Good health supercedes appearance Good health supercedes appearance Healthy lifestyle means more than absolute body weight Healthy lifestyle means more than absolute body weight

15 Weight Classification by BMI Underweight: BMI < 18.5 Underweight: BMI < 18.5 Healthy Weight: BMI 18.5 – 24.9 Healthy Weight: BMI 18.5 – 24.9 Overweight: BMI 25.0 – 29.9 Overweight: BMI 25.0 – 29.9 Obesity: BMI >30.0 Obesity: BMI >30.0

16 Defining Obesity Overweight = 10-20% above ideal body weight Overweight = 10-20% above ideal body weight Mild Obesity = >20% Mild Obesity = >20% Moderate Obesity > 40% Moderate Obesity > 40% Super Obesity > 80% Super Obesity > 80% Morbid Obesity > 100% Morbid Obesity > 100%

17 Distribution of Body Fat Central Obesity – Abdominal fat (apple shape) with higher risk of Diabetes Type 2, HTN, CVD Central Obesity – Abdominal fat (apple shape) with higher risk of Diabetes Type 2, HTN, CVD Hip and thigh body fat (pear shape) – less harmful Hip and thigh body fat (pear shape) – less harmful Waist circumference: Women > 80-88 cm; Men > 94-102 cm; high risk Waist circumference: Women > 80-88 cm; Men > 94-102 cm; high risk

18 Energy Balance and Body Composition- FON 241; L. Zienkewicz Body Types: Apple shape: Intra-abdominal fat. Common in men. Pear shape: Lower-body fat Common in women.

19 Estimating Body Fat Content Measure % body fat Measure % body fat Hydrodensitometry: Underwater weighing (most accurate) Hydrodensitometry: Underwater weighing (most accurate) Fatfold measures/calipers (Triceps, abdomen, thigh, etc) Fatfold measures/calipers (Triceps, abdomen, thigh, etc) Desirable amount of body fat 21 – 35% for women 8 – 24% for men

20 Methods Used to Assess Body Fat Bioelectrical impedanceFatfold measures Air displacement plethysmography Dual energy X-ray absorptiometry (DEXA) Hydrodensitometry

21 Energy Balance,Body Composition and Weight Management Chapters 8 and 9

22 Skinfolds Common field method Relationships among selected skinfold sites and body density Caliper exerts constant tension of 10 g/mm 2 Sum of skinfolds indicates relative fatness of individual

23 Anatomical Landmarks for Skinfold Measurements Chest Abdomen Triceps Suprailium Thigh

24 Girth Measurements Uses 3 sites: see Appendix F Men: right forearm, abdomen, right upper arm or buttocks Women: abdomen, right thigh, right forearm or right calf Pattern of fat distribution Predicting Body Fat

25 Waist-to-Hip Ratio Predicts disease risk according to apple or pear shape Disease Risk according to Waist-to-Hip Ratio Essential and Storage Fat Techniques to Assess Body Composition Determining Recommended Body Weight

26 Bioelectrical Impedance Hydrated, fat-free body tissues and extracellular water facilitate electrical flow compared to fat tissue because of greater electrolyte content of fat-free component.

27 Health Risks of Obesity Cardiovascular disease Cardiovascular disease Type 2 Diabetes Type 2 Diabetes Hypertension Hypertension Some cancers Some cancers Gallbladder disease Gallbladder disease Osteoarthritis Osteoarthritis Costly for healthcare system Costly for healthcare system

28 Fat Cell Development Fat cells increase in numbers (hyperplastic obesity) and in size (hypertrophic obesity) Fat cells increase in numbers (hyperplastic obesity) and in size (hypertrophic obesity) Fat cell numbers increase most rapidly in later childhood and early puberty; in times of positive energy balance Fat cell numbers increase most rapidly in later childhood and early puberty; in times of positive energy balance Fat cell size increases when energy intake exceeds expenditure (feasting) Fat cell size increases when energy intake exceeds expenditure (feasting)

29 Fat Cell Development When fat cells have enlarged and energy intake continues to exceed energy expenditure, fat cells increase in number again. During growth, fat cells increase in number. When energy intake exceeds expenditure, fat cells increase in size. With fat loss, the size of the fat cells shrinks, but not the number. Fat cells are capable of increasing their size by 20-fold and their number by several thousandfold.

30 Causes of Obesity Psychological/Environmental Psychological/Environmental Learned response/habit Learned response/habit Food satisfies emotional needs Food satisfies emotional needs stress, boredom, depression, feeling unloved stress, boredom, depression, feeling unloved Food as reward Food as reward External cues External cues time, sight, smell time, sight, smell Availability Availability

31 Environment Overeating Overeating Present & past eating influences current body wt Present & past eating influences current body wt Increase availability of convenient food, large portions, energy- dense foods Increase availability of convenient food, large portions, energy- dense foods Physical Inactivity Physical Inactivity Modern technology replaces physical activities Modern technology replaces physical activities Physical activity allows people to eat enough food to get needed nutrients Physical activity allows people to eat enough food to get needed nutrients

32 Environmental Causes (cont) High kcal, high fat foods available; inexpensive, advertised (ex. Fast foods) High kcal, high fat foods available; inexpensive, advertised (ex. Fast foods) Physical inactivity: change in modern technology, TV watching Physical inactivity: change in modern technology, TV watching Est. that < 1/3 people exercise 30 min./day; 40% do not exercise at all Est. that < 1/3 people exercise 30 min./day; 40% do not exercise at all

33 Causes of Obesity - Genetics Heredity (twin research, adoptive children research) Heredity (twin research, adoptive children research) Set-Point Theory Set-Point Theory Bodys natural regulatory centers maintain homeostasis at set point Bodys natural regulatory centers maintain homeostasis at set point Human body tends to maintain a certain weight Human body tends to maintain a certain weight Obesity is the state of very high set point Obesity is the state of very high set point

34 Genetic Causes Leptin (ob protein) Leptin (ob protein) Hormone produced by adipose tissue Hormone produced by adipose tissue Decreases appetite Decreases appetite Increases energy expenditure Increases energy expenditure Central fat pattern produces less leptin than peripheral fat Central fat pattern produces less leptin than peripheral fat More research needed More research needed

35 Genetic Causes - Ghrelin Protein produced by stomach cells Protein produced by stomach cells Acts as a hormone to decrease energy expenditure, increase appetite Acts as a hormone to decrease energy expenditure, increase appetite

36 Even though the risk for premature illness and death is greater for those who are overweight, the risk also increases for individuals who are underweight 4.6 Disease and Mortality Risk Based on BMI

37 Because of the typical reduction in physical activity, each year the average person gains 0.68 kg of body fat and loses 0.23 kg of lean tissue 15.8 Body Composition Changes for Adults in the U.S

38 OBESITA Dati Istat OBESITA Dati Istat

39 CONFRONTO TRA DATI RIFERITI E DATI MISURATI DEL SOVRAPPESO E DELLOBESITA NELLA POPOLAZIONE 18 ANNI Dati riferiti: ISTAT Indagine multiscopo sulle famiglie Aspetti della vita quotidiana – Anno 2003 Dati misurati: Ministero della Salute – ISS: Progetto CUORE – anni 1998-2002

40 Dimensioni dellObesità negli adulti in Italia Validità delle informazioni disponibili Dati riferiti: gli intervistati tendono a sottostimare leccesso di peso - buona rappresentatività, ma probabile sottostima dellobesità Dati misurati: aree selezionate in modo opportunistico – buona accuratezza, ma il campione potrebbe rappresentare in modo distorto la realtà nazionale Dati riferiti : 1 su 2 sovrappeso (BMI 25) 1 su 3 sovrappeso (BMI 25) Dati misurati: 3 su 4 sovrappeso (BMI 25) 1 su 2 sovrappeso (BMI 25)

41 Fonte: Progetto del Ministero della Salute Sorveglianza ed educazione nutrizionale basata su dati locali per la prevenzione di malattie cronico-degenerative anni 2000-2002. Dimensioni dellObesità infantile in 6 diverse aree Italiane

42 Confronti internazionali, indagini con misurazioni dirette usando le soglie dellIOTF, 2008 Difficile fare paragoni validi a causa di gruppi di età diversi e mancanza di studi recenti che utilizzino le soglie IOTF * Bambini 7-9 anni

43 Ma il cambiamento cè dagli anni 70 Distribuzione IMC anni 70 dati INRAN e 2008 OKkio, pool ASL (Abruzzo meno Sulmona, Salerno, Cosenza) 0% 5% 10% 15% 20% 25% 1112131415161718192021222324252627 Anni 702008 mediana anni 70 = 16,3 mediana 2008 = 17,9 (n=1784)

44 Distribuzione percentuale dei bambini per consumo di frutta e verdura. Italia, 2008

45 Distribuzione percentuale dei bambini per consumo di bevande zuccherate e/o gassate. Italia, 2008

46 Attività fisica il giorno prima dellindagine Il 26% dei bambini non ha svolto attività fisica il giorno precedente lindagine 22% > 22% e 24% > 24% e 27% > 27%

47 Attività fisica settimanale extrascolastica Il 25% dei bambini svolge attività fisica per non più di unora a settimana I maschi tendono a essere più costanti Nei piccoli centri più che nelle grandi città 21% 60% 20% 30% 56% 14% 0-12-34-7 numero di giorni con almeno un'ora di attività fisica

48 Modalità utilizzata dai bambini per recarsi a scuola modalità utilizzata per raggiungere la scuola 13% 59% 25% 1%2% scuolabusmacchinaa piedibiciclettaaltro modo

49 Numero di ore giornaliere dedicate alla TV e ai videogiochi Solo il 3% dei bambini dedica a TV e videogiochi meno di 1 ora al giorno L11% dedica a queste attività più di 4 ore al giorno 3 10 31 30 15 11 < 111 – 22 – 33 – 4> 4 numero di ore/die dedicate a comportamenti sedentari

50 Prevention Eat regular meals and limit snacking Eat regular meals and limit snacking Drink water in place of high-kcal beverages Drink water in place of high-kcal beverages Select sensible portion sizes Select sensible portion sizes Limit daily energy intake to energy expended Limit daily energy intake to energy expended Limit sedentary activities; be physically active Limit sedentary activities; be physically active

51 Role of Metabolism in Nutrition

52 Metabolism Metabolism – process by which living systems acquire and use free energy to carry out vital processes Metabolism – process by which living systems acquire and use free energy to carry out vital processes Catabolism (degradation) Catabolism (degradation) Nutrients and cell constituents are broken down for salvage and/or generation of energy Nutrients and cell constituents are broken down for salvage and/or generation of energy Exergonic oxidation Exergonic oxidation Anabolism (biosynthesis) Anabolism (biosynthesis) Endergonic synthesis of biological molecules from simpler precursors Endergonic synthesis of biological molecules from simpler precursors Coupled to exergonic processes through high-energy compounds Coupled to exergonic processes through high-energy compounds

53 Role of Metabolism in Nutrition Definition: the sum of all biochemical changes that take place in a living organism. Group these reactions into two types: anabolic catabolic Reactions: require energy release energy Produce: more complex more simple compounds compounds Modus Operandi: Occurs in small steps, each of which is controlled by specific enzymes.

54 Relationship Between Catabolic and Anabolic Pathways Catabolic pathways Catabolic pathways Complex metabolites are transformed into simpler products Complex metabolites are transformed into simpler products Energy released is conserved by the synthesis of ATP or NADPH Energy released is conserved by the synthesis of ATP or NADPH Anabolic pathways Anabolic pathways Complex metabolites are made from simple precursors Complex metabolites are made from simple precursors Energy-rich molecules are used to promote these reactions Energy-rich molecules are used to promote these reactions

55 Examples of each type of metabolism: Anabolic PathwaysCatabolic Pathways Protein BiosynthesisGlycolysis GlycogenesisTCA (Krebs cycle) Gluconeogenesisß-oxidation Fatty Acid SynthesisRespiratory Chain Other useful generalizations: Some of the steps in the anabolic path (going uphill) may not be identical to the catabolic path--but some are shared. ATP Generated Provides Energy FOR

56 56 Il metabolismo dei carboidrati Tortora, Derrickson Conosciamo il corpo umano © Zanichelli editore 2009

57 57 Il metabolismo dei carboidrati Tortora, Derrickson Conosciamo il corpo umano © Zanichelli editore 2009

58 Carbohydrate metabolism Glucose 55% Oxidation 20% Glycolysis 25% Re- uptake 10% Muscle 45% Brain

59 59 Il metabolismo dei lipidi Tortora, Derrickson Conosciamo il corpo umano © Zanichelli editore 2009

60 1.Triglycerides-----consists of fatty acids major energy component of fat 2. Essential dietary fatty acids-----linoleic, linolenic, arachidonic precursors for membrane phospholipids 3. Cholesterol precursors for steroid hormones and bile acid Fat metabolism

61 Lipoprotein Fat metabolism Hydrophilic surface Phospholipid Cholesterol Protein Hydrophobic core Triglyceride (TG) Lipoprotein Density TG Cholesterol Phospholipid Protein Chylomicron s VLDL IDL LDL HDL High Low

62 1. Protein synthesis 2. Oxidation 3. Gluconeogenesis-----Krebs cycle, a reversal of glycolysis 4. Ketogenesis-----ketone body (acetoacetate) 5. Ureagenesis-----urea (into urine) through the Krebs- Henseleit cycle Protein metabolism Amino acids Protein (Diet) Protein E N E N Glucose Amino acids N Pyruvate

63 Dei 20 aminoacidi contenuti nelle proteine, 9 sono essenziali. Fabbisogno (mg/kg)Lattante (4-6 mesi)Bambino (10-12 anni)Adulto Istidina(29)-- Isoleucina882810 Laucina1504414 Lisina994912 Metionina e cistina722413 Fenilalanina e tirosina1202414 Treonina74307 Triptofano1943 Valina932813 TOTALE (esclusa istidina) 71523186

64 64 Protein Metabolism

65 65 Alcohol Metabolism Effects

66 How do we employ energy? MECHANICAL- muscle contraction ELECTRICAL- maintaining ionic gradients (e.g., Na-K ATPase; 70% of ATP used by kidney & brain used to maintain gradient) CHEMICAL- biotransformation of molecules (e.g., synthesis degradation, metabolism)

67 International Unit of Energy: Joule : energy used when 1 Kg is moved 1 meter by a force of 1 Newton : kJ = 10 3 J; MJ = 10 6 J : 1 kcal = 4.184 kJ : Protein:17 kJ or 4 kcal/g CHO:17 kJ or 4 kcal/g Fat:37 kJ or 9 kcal/g

68

69 Measurement of Energy Intake Energy needs Metabolic Energy Yields

70 Conversion Efficiency: Food to Usable Energy 40% used to make high energy phosphate bonds 60% lost (?) as heat

71 Energy Balance Sources of fuel for energy Sources of fuel for energy Input from diet: carbs, fat, prot, alcohol Input from diet: carbs, fat, prot, alcohol Stored energy: glycogen, fat, muscle Stored energy: glycogen, fat, muscle Energy outgo from: Energy outgo from: Basal metabolism Basal metabolism Physical activity Physical activity Dietary thermogenesis Dietary thermogenesis

72 Energy Out Energy of food = Body Energy = ATP Energy of food = Body Energy = ATP Overall efficiency 25%, 75% released heat Overall efficiency 25%, 75% released heat Energy out: Energy out: 3 main components: 3 main components: Basal Metabolic Rate Basal Metabolic Rate Thermic Effect Food Thermic Effect Food Physical activity Physical activity

73 BMR > Activity > Dietary Thermogenesis

74 Basal Metabolic Rate BMR = number of calories would need daily simply to stay alive if were totally inactive, in bed, awake for 16 hours & slept for 8 hours BMR = number of calories would need daily simply to stay alive if were totally inactive, in bed, awake for 16 hours & slept for 8 hours Harris-Benedict Equation: Harris-Benedict Equation: Women: 655+(9.56 x weight in kg)+(1.85 x height in cm)- (4.7 x age)=BMR Women: 655+(9.56 x weight in kg)+(1.85 x height in cm)- (4.7 x age)=BMR Men: 67+(13.75 x weight in kg)+(5.0 x height in cm)- (6.9 x age)=BMR Men: 67+(13.75 x weight in kg)+(5.0 x height in cm)- (6.9 x age)=BMR

75 1) Basal Metabolic Rate 50-70% Energy Expenditure 50-70% Energy Expenditure Maintain basic metabolic processes Maintain basic metabolic processes CellsMusclesTemperature regulation Growth Osmotic pumps Osmotic pumps Protein synthesis Protein synthesis Heart Heart Respiratory system Respiratory system Digestive tract Digestive tract Individual variation Individual variation Within individual variation Within individual variation 10%

76 Factors affecting BMR 1) Body Size & Composition 1) Body Size & Composition Lean tissue BMR Lean tissue BMR Body weight wt lean tissue (but also fat) Body weight wt lean tissue (but also fat) 2) Age: 2) Age: age Lean tissue age Lean tissue 3) Sex: Men lean 3) Sex: Men lean 4) Activity: Exercise lean tissue 4) Activity: Exercise lean tissue

77 Factors affecting BMR 5) Growth BMR 5) Growth BMR Children, pregnancy Children, pregnancy 6) Fasting/starvation: BMR 6) Fasting/starvation: BMR 7) Fever/stress BMR 7) Fever/stress BMR 8) Smoking/caffeine: BMR 8) Smoking/caffeine: BMR

78 2) Energy Out: Dietary Thermogenesis Dietary thermogenesis Dietary thermogenesis Energy to digest, absorb, metabolize food Energy to digest, absorb, metabolize food About 10% of calories eaten About 10% of calories eaten

79 2) Thermic Effect of Food 3-6 hours following ingestion 3-6 hours following ingestion ~10% energy intake ~10% energy intake 2000 kcal diet = 200 kcal TEF 2000 kcal diet = 200 kcal TEF Affected by: Affected by: Meal size/frequency Meal size/frequency Composition: Protein > Carbs/fat Composition: Protein > Carbs/fat Genetics Genetics

80 3) Energy Out: Physical Activity Physical Activity affected by: Physical Activity affected by: Intensity -- how vigorous Intensity -- how vigorous Time spent Time spent Body weight Body weight

81 3) Physical Activity Variable: 20-40% Variable: 20-40% Working muscles require energy Working muscles require energy Heart/lung extra energy Heart/lung extra energy Amt energy used depends on: Amt energy used depends on: Muscle mass Muscle mass Body weight Body weight Activity nature & duration Activity nature & duration

82 Activity Level and Metabolism Activity can account for 20-30% of metabolism Activity can account for 20-30% of metabolism 1. Sedentary = Multiplier 1.15 x BMR 2. Light activity (Normal Every day activities) = Multiplier 1.3 x BMR 3. Moderately Active(exercise 3-4 x s week) = Multiplier 1.4 x BMR 4. Very Active (exercise more than 4 x s week) = Multiplier 1.5 x BMR 5. Extremely Active (exercise 6-7 x s week) = Multiplier 1.6 x BMR

83 Activity Level and Metabolism If you change Light activity (Normal Every day activities) to Moderately Active (exercise 3-4 x s week) daily caloric burning goes up 7.7% If you change Light activity (Normal Every day activities) to Moderately Active (exercise 3-4 x s week) daily caloric burning goes up 7.7% If you change Light activity (Normal Every day activities) to Very Active (exercise more than 4 x s week) daily caloric burning goes up 23% If you change Light activity (Normal Every day activities) to Very Active (exercise more than 4 x s week) daily caloric burning goes up 23% If you change Light activity (Normal Every day activities) to Extremely Active (exercise 6-7 x s week) daily caloric burning goes up 38.5% If you change Light activity (Normal Every day activities) to Extremely Active (exercise 6-7 x s week) daily caloric burning goes up 38.5%

84 Energy Requirements Difficult to estimate Difficult to estimate Direct measurement Direct measurement Research Research Estimates from averages Estimates from averages Based on age/sex Based on age/sex Assume light/moderate activity Assume light/moderate activity Estimate TEF Estimate TEF


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