Module 7 - Lecture - nutrition textbook PDF

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Module #7 – Lecture Notes Energy -

Unit of measurement: Kcal = Calories = 1000 calories 1Kcal = 4.18 kJ 2000 Kcal = 8400 kJ = 8.4 mJ

Total energy Requirements -

TEE = Basal needs + Activities + Thermogenesis Men burn more energy Young people need more energy Basal metabolism takes the most energy Activity takes the 2nd most energy. In an active person less enery is spent on basal. Thermogenesis takes the least amount of energy and is always constant

Baal Energy Needs -

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Basal Energy Expenditure (BEE) Basal Metabolic Rate (BMR) Measurement of O2 consumption + CO2 released at rest, generally carried out after waking up. Methods to measure BMR Ventilated hood Human Calorimeter Direct (heat) Indirect (O2,CO2)

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Rough estimate of BMR Men – 1.0 kcal/kg/hours Women – 0.9 kcal/kg/hours 120 lbs / 2.2 kg = 54.5 kg 0.9 kcal/kg/hours x 54.5 kg x 24 hours = 1178 kcal

Resting Metabolic Rate (RMR) -

Same as REE (Resting Energy Expenditure) Often measured in place of BMR, using formula (Harris Benedict Equations) This measurement is usually 10-20% higher than BMR

BMR and Body Composition -

Lean Body Mass (LBM) All non-fat components (muscles, bones, organs and fluids) The more LBM a person has, the more Kcal they use/burn.

Obesity -

As overall body fat increases, there is an overall increase LBM therefore BMR increase as well. Decrease in skeletal muscle Increase in size of other organs (GIT,heart) Increase in vascularization (veins, arteries) Increase in # of fat cells

What is Thermogenesis? -

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Generation of heat An increase in metabolic note that occurs in response to some stimulus Types: Meds/drugs • Caffeine (0Kcals) • Alcohol (7Kcals) • Smoking nicotine (helps people lose weight) Exposure to cold • “shivering” is a stimulus to keep warm Stress responding to it (eat more or fast) Food DIT (dietary-induced thermogenesis) Why does metabolic rate rise with food intake?

Digestion Enzymes Hormones Increase gut mobility Absorption Cellular process (takes energy) Increase biosynthesis Protein fat Glycogen non-essential amino acids Recommendations: Energy Intake -

Establishing energy recommendations (DRI,2002) A lot of people will get too many kcal EER: Average energy intake (Kcal/day) that maintain energy balance This is equal to the EAR value. (estimate average requirement)

Calculating EER values

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Healthy Body Weight -

Historical: life insurance Controversial: is it accurate? Key Personal health must be Individually assessed by a Qualified health professional looking at Several measures of health

BMI: Body Mass Index -

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BMI = Weight (kg) / Height 2 (m) Formula = (kg) / (m) 2

Benefits of using BMI Reasonably accurate predictor of current health and future morbidity for most adult people One widely used measure of health risk associated with under- and over- weight Compares well with various measures of body fat Fat-fold measures Bioelectrical impedence Underwater weighing Others (section 7.5 smolin)

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Limitations of using BMI Use for Adults >19 yrs of age Not for pregnant women or lactating people Special consideration Children and adolescents Young adults (>19) but not yet reached full growth potential Muscular athletes/adults “heavy set” but “fit” individual Certain ethnic and special groups Older adults >65 yrs of age • Height decrease and weight increase or decrease BMI does not address issue of body fat distribution

Apple is more of a health risk meaning fat around stomach Pear is less of a health risk than apple because it is carried in the hips and legs

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Health Problems Associated with Overweight and Obesity: Summary -

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Chronic disease + Ischemic Stroke Insulin Resistance / Type 2 Diabetes Dyslipidemias Levels of fat where they should not be Increase in total cholesterol Increase Low-density lipoprotein Decrease high-density lipoprotein Increase levels of triglycerols Hypertension (high blood pressure) Osteoarthritis (stress in joints like athletes) Increase in # of type of cancers Adipose tissues creates estrogen Visceral adiposity more active fat cells Metabolically active Inflame markers Insulin resistance therefore is increase in insulin Gallbladder disease

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Sleep aprea / respiratory problems Psychosocial problems Functional limitations Impaired fertility

Does knowledge translate to behaviour change? - No - Two personal experiences Young man at gas station Chocolate chip and milk Tessa doing her M.Sc. of Guelph Why don’t we always follow dietary and/or health recommendations? -

Habit Style/food $ availability Accessibility Taste Media Sport/celebrity

Obesity: Public Health Challenges -

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Ambivalence / lack or concern / ignorance is bliss Eating/enjoyment of food Leisure and pleasure Culture / tradition Personal choice Priorities Misinformation and myths Parental disconnect re: children’s weight and health risks 9% of parents said their kids were overeight In reality 28% of kids were

Call to Action -

Public health efforts to curb obesity “British government targets obesity (2008) $750 000 spent, dictation did all works CDPAC: Chronic Disease Preventation Alliance of Canada (2010) Dietitians Canada • Environment more available for be good stress • ID of obesity and overweight earlier

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Increase in available/access/affordable of nutritious fonds Protect children from marketings (fat, sugar and salt)

Healthy weight loss -

95% attempts at weight loss fail to produce long term healthy body weight

Our focus -

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Why do most diets fail Weight cycling or jumping up and down (yoyo dieting) Root cause A very common phenomenon in north America Culture has misdirection of attention on weight loss as goal Yo-yo diets are dangerous on psychological health Instead : change lifestyle and eating habits Healthy weight loss & long term weight maintenance Follow sensible, balanced diet you enjoy Across all food groups • Lower fat • Adequate protein + fibre = full Eat lower calories Ein – Eout = -ve weight loss or 0. Enjoy regular physical activity Burns more Kcals Prevent LBM loss • Even build LBM • Increase BMR Attaining and maintaining a healthy weight: blueprint for action A successful diet Decrease kcalories – 500 Kcal deficit = 1-2 lbs/week • Minimum consumption of W1200 – M1500 calories Must be adequate in all other nutrient (nutrient rich food) Should have high satisty value Adaptible for family meals or eating out with friends Must have reasonable cost Easy to stick to it and no pain Teach, support, result in change of eating habits

Fad diets/popular diets -

Crash diets Fasting or starving

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Last meal body use glucose + fat (Red blood cells requires glucose) 12-15 hrs later depleted liver glycogen stores • Body protein breakdown begins because you needs it to produce more glucose. (gluconeogenesis) • Other cells using fat Next 2-3 days massive loss of LBM (Heavy) • Loss of protein • Water • Electrolytes (K,Cl,Na) • Therefore lost of weight Slowly adaptation to starving (ketosis) • Fat most tissues 9kcals • Fat Ketone bodies (substitute for glucose to brain) • LBM glucose slowly • Therefore decreases BMR (to conserve energy, shut down what body processes you can.) o Hard to exercise o Depleting LBM Low CHO / high protein diets Similar change of metabolism as fasting Countenintuitive Even though consuming lots of protein, because there is insuficeint carbs and decrease kcal in order to supply, enough glucose, metabolism causes gluconeogenesis from LBM. You need around 100G car/day to spare body protein breakdown. 200-300 g high fibre carb • 45-65% kcal “fat burn in a carb flame”...