Weight Management Flashcards
Body Weight and Body Composition: Defining healthy body weight
- what should be the primary focus of weight management efforts?
- The criterion of fashion: unrealistic ideals
- accepting a healthy body weight
- the criterion of health
- Obesity is a major chronic disease risk factor
- Range of healthy body weights the promote good health and longevity
Body Mass Index
- Weight in kg / height in m2 OR
- Weight in lb/ height in inches2 x 703
healthy weight
BMI 18.5 to 24.9
Underweight
BMI <18.5
Overweight
BMI 25.0 to 29.9
Obese =
BMI > 30
Body composition
- Diagnosis of overweight/obesity requires a BMI value plus some measure of body composition and fat distribution
- Central obesity
Visceral fat: fat stored within the abdominal cavity in association with abdominal organs - what are the health concerns associated with central obesity?
Central obesity
“Apple profile” of central obesity
- common in postmenopausal women and even more common in men
- Influential factors: smoking, alcohol consumption, and physical activity
“Pear profile” created by subcutaneous fat
Waist circumference
- Good indicator of fat distribution and central obesity
- High risk: > 35 inches for women or > 40 inches for men
Skinfold measures
- accurate estimate of total body fat and a fair assessment of the fat’s location
How much body fat is too much?
- Depends partly on the person
- Man within recommended BMI: 18% to 24% fat composition
- Woman within recommended BMI: 23% to 31% body fat
- Athletes: 5% to 10% for men, 15% to 20% for women
Health Risks of Obesity
- hypertension
- type 2 diabetes
- (high blood lipids, cardiovascular disease, sleep apnea, osteoarthritis, abdominal hernias, some cancers, varicose veins, gout, gallbladder disease, kidney stones, respiratory problems)
- Social stigma, prejudice
- Increased costs
- Insurance premiums
- Clothing
Causes of Obesity
- Genetics and weight
- Genes influence eating behaviour and weight
- Impact of body composition
- Complex interactions among genes
- Interrelated with environment factors
Genetics and Weight: Lipoprotein Lipase (LPL)
“lets store more fat!”
- cell surface enzyme that hydrolyzes triglycerides and promotes fat storage
- higher level of LPL activity in fat cells of obese people - makes fat storage efficient
Genetics and Weight: Leptin
- protein (hormone) coded for by obesity (ob) gene
- suppresses the appetite. After you eat a massive meal and have storage, leptin is produced and tells you you are full and do not need to eat anytime soon. It is a hormone that helps with natural regulation of feasting and fasting in normal routines
Genetics and Weight: Ghrelin
- hormone that stimulates appetite and promotes efficient energy storage
Fat Cell Development (4 steps)
- during growth fat cells increase in number
- when energy intake exceeds expenditure, fat cells increase in size
- when fat cells have enlarged and energy intake continues to exceed expenditure, fat cells increase in number again
- with fat loss, the size of the fat cells shrinks, but not the number
Obesity Treatment: Principles
- weight-loss advice does not apply equally to all overweight people
- many factors should be considered (extent of overweight, age, health, genetics)
- Must weigh the benefits and risks of weight loss
- Obesity treatment should integrate healthy eating patterns, physical activities, supportive environments, and psychosocial support
- Successful strategies embrace small changes, moderate and sustained losses, and reasonable goals
Reasonable Strategies for weight loss to lower disease risk
- reduce body weight by about 5% to 10% over 6 months
- A healthful eating plan
- Nutritional adequacy
- reduce body weight by about 5% to 10% over 6 months
Maintain a lower body weight over the long term
At minimum, prevent further weight gain
A healthful eating plan
A realistic energy intake
- provides less energy than the person needs to maintain present body weight
- Not too restrictive
- men: 1500-1800 kcalories per day
- Women 1200-1500 kcalories per day
Nutritional Adequacy
- difficult to achieve on <1200 kcal/day
- nutrient-dense food selections
- dietary supplement with <100% of daily values for minerals/vitamins
Reasonable Strategies for Weight Loss: A Healthful Eating Plan
- Small portions (less food at each meal, prepared meal plans can assist with portion control)
- Lower energy density (fruits, vegetables, broth-based soups)
- Sugar and alcohol (limit intake)
- Meal spacing (total quantity consumed should be controlled)
- Adequate water (substitute for nutrient-poor kcaloric beverages)
Reasonable Strategies for Weight Loss: Physical Activity
Physical activity: more likely to lose more fat, retain more muscle, and regain less weight when physical activity is combined with energy restriction. Reduces abdominal obesity; improves blood pressure, insulin resistance, fitness of heart and lungs
Energy expenditure: directly increases energy output. energy spent on various activities differs.
Basal Metabolic Rate (BMR): elevated following vigorous physical activity. Rises over time as more lean tissue is added