Nutrition chapter 7
bioelectrical impedance
(BIA)- hand held equipment is also available -common method to assess body composition
air displacement
(bodpod) -common method to assess body composition
low carb diet
-30-50 percent of kcal from protein, restrict carbs to 40% of kcal or less -rapid initial weight loss due to fluid losses -Caution: metabolism of fat and protein for fuel can alter pH of blood -caution: excessive intake of high fat sources of animal protein can affect long term cardiovascular health and kidney health -can be successful weight loss strategy if kcal deficit can be maintained over time
BMI is a convenient screening tool for overweight and obesity but does not directly assess body composition
-BMI is a simple ratio of weight and height -body composition refers to the percent of the body that is lean vs. fat
proportion of american adults who are overweight and obese
-about 2/3 of american adults are overweight or obese -of these, about half or 1/3 are obese
factors taken into account when estimating EER
-age -male or female -height -weight -activity level
weight loss and maintenance of it will likely require more than 150 minutes per week of moderate intensity physical activity
-aimed to reduce risk of chronic diseases -weight loss usually requires more physical activity -duraition and consistancy are more important than intensity
EER varies by age, gender, and activity level
-as age increases, EER declines -men tend to have higher EER than women -EER increases as physical activity level increases
reality of weight loss
-as we lose weight, our energy needs decrease slightly -hormonal changes affect metabolic rate and appetite -unconscious adjustments in physical activity -it takes about 3 years to fully realize the effect of kcal defecit
mindful eating can enhance weight management efforts
-avoid triggers for overeating or unhealthy choices -improve awareness of hunger and satiety
risks of bariatric surgery
-bleeding -blood clots -hernias -infections -nutrient deficiencies - 2% risk of death
components of energy intake and energy expenditure from foods and beverages
-carbs -proteins -fat -alcohol
healthful strategies for increasing body weight
-choose energy dense foods -nuts and nut butters, vegetable oils, granola, dried fruit, bananas, avocados, dried milk powder to boost protein and calories, nutrient dense drinks,liquid nutritional supplements
energy density for controlling calorie intake
-comparison of kcal content to weight of food -foods high in fat are more energy dense than foods of mostly carbs but may not fill you up -foods high in water and fiber have low energy density but fill you up without many kcal
3 key elements of a sound weight loss program
-control calorie intake -perform regular physical activity -control problem behaviors
android (upper body) obesity
-deposition of fat around the waist -waist circumference over 40 inches for men and 35 inches for women -associated with increased risk of chronic diseases -fat is available to the liver; affects glucose and lipid metabolism -testosterone promotes android obesity (most common among men and post-menopausal women) -apple shaped
possible causes of underweight
-genetics -growth spurt -cancer -infectious disease -digestive tract disorders -extreme dieting -excessive physical activity
why are VLCDs not long term solutions for weight management
-include weight loss, but they do not change problem behaviors -weight regain is VERY common
discuss how following factors influence basal metabolism
-lean body mass -body surface area -male or female -body temp -thyroid hormone levels -stress -growth -caffeine use -tobacco use
very low calorie diet (VLCD)
-liquid diet providing 400-800 kcal per day; adequate in micronutrients and protein, but low in fat and carbs -use should be monitored by a physician -known as protein sparing modified fast
why are beverage choices just as important as food choices
-liquid kcal are not as satiating as food kcal, but can quickly add up -choose water
strategies to overcome weight loss plateau
-measure and monitor food intake; be aware of calorie creep -further reduction in kcal may be necessary if weight loss has resulted in decreased energy requirements -change intensity of physical activity -incorporate strength training to build lean mass and boost energy expenditure
basal metabolism
-minimal amount of energy required to keep a resting, awake body alive in a warm, quiet environment (energy for breathing brain function) -accounts for 60-75 percent of total energy expenditure
most successful weight loss plan is one that a person can stick with
-monotony leads to boredom -overly restrictive diets can lead to nutrient inadequacy -lack of flexibility makes some plans difficult to follow
success of bariatric surgery
-most successful long term result of any weight loss method -reduces development/progression of weight related conditions (type 2 diabetes, hypertension, cardiovascular disease)
use food labels to select food with lower energy density
-observe serving sizes -compare kcal content of various foods -compare kcal content of serving size
weight loss med that affects digestion and absorption of nutrients
-orlistat -liraglutide
weight loss medications that affect appetite
-phentermine -lorcaserin hydrochloride -phentermine + topiramate -buproprion + naltrexone -typically reserved for people with BMI over 30
health professionals and community organizations that are well equipped to help clients lose excess body weight
-physicians and nurses measure and monitor weight related health parameters -registered dietition nutritionists assist with nutrition assessment, education, and intervention -exercise phyiologists assist with fitness assessment, education, and intervention
characteristics of unreliable (fad) diets
-promote quick weight loss -limit food selections -use testimonials for marketing -promoted as cure-alls -recommend expensive supplements -behavior modification not included -exercise not included -critical/ skeptical about the scientific community
gynoid/lower body obesity
-refers to deposition of fat in the buttocks and thighs -not closely linked to chronic disease risk -estrogen and progesterone promote lower body gynoid obesity (most common among pre-menopausal women) -pear shaped
low fat diet
-restrict fat to 20% of kcal or less -choosing foods with lower energy density can promote satiety without contributing as many kcal -very strict approaches may reverse cardiovascular disease -caution: deficiencies of essential fatty acids or fat soluble vitamins are possible -can be a successful weight loss strategy if kcal deficit can be maintained over time
importance of self monitoring for weight management
-reveals problem behaviors -enable tracking of progress on behavior goals in addition to the numbers on the scale
kcal deficit that is typically required to lose 1 pound per week
-weight loss includes lean mass + fat mass - 1 pound of weight loss= 3500 kcal -3500 kcal/ 7 days a week = 500 kcal/ day -in theory, reducing kcal intake by about 500 below energy needs results in weight loss of about 1 pound per week -in reality weight loss is not linear and factors other than his simple math, so this overestimate weight loss
1 to 2 pounds per week is a safe and sustainable rate of weight loss
-when weight is lost, it is a combination of lean and fat mass; the goal is to maximize fat loss and minimize loss of lean tissue -rapid weight loss (>2 lb/ week) is likely due to loss of water; not sustainable
normal weight
18.5-24.9 BMI
overweight
25-29.9 BMI
underweight
<18.5 BMI
obese
> or equal to 30 BMI
basal metabolism on body weight
A low BMR due to factors such as thyroid problems or energy restriction is linked to weight gain
underweight
BMI < 18.5
ratio of fat to lean tissue
a high ratio of fat mass to lean body mass is correlated with weight gain
childbearing
a pattern of weight gain during the childbearing years can occur to support fetus. fat stored during pregnancy to support lactation may not be lost in women who do not breastfeed
skin disorders
accumulation and trapping of moisture and microorganisms in tissue folds
negative energy balance
calories in is less than calories out, more exercise than eating, decrease in weight
positive energy balance
calories in is more than calories out, more eating and less working out
skinfold thickness
common method to assess body composition
dual energy x-ray absorptiometry (DEXA)
common method to assess body composition -MOST ACCURATE but expensive and impractical for everyday use
premature death
comorbidities and greater risk factors for numerous chronic diseases and complications
direct calorimetery
determine energy expenditure by measuring heat released from the body
indirect calorimetery
determine energy expenditure by measuring oxygen uptake and carbon dioxide output
shorter stature
early onset of puberty
fat uptake by adipose tissue
efficiency of fat storage is high in some obese individuals and may even increase with weight loss
thermic effect of food
energy needed to digest, absorb, and metabolize nutrients; accounts for 5-10 percent of total energy expenditure
adaptive thermogenesis
energy spent on nonvoluntary activities that maintain body temperature; accounts for <5 percent of total energy expenditure
type 2 diabetes
enlarged adipose cells poorly bind to insulin and inadequately respond to insulin signals; reduced synthesis of factors that promote insulin action and increased synthesis of factors that counter insulin action
various cancers
estrogen and other hormones contribute to tumor growth by adipose cells; increased hyperinsulinemia or insulin resistance; synthetic inflammation associated with cancer risk; excess calorie intake may encourage tumor development
age
excess body fat is more common in adults and middle-aged individuals due to loss of lean body mass and reduction in physical activity
dietary consumption
excess calorie intake from saturated fat, alcohol, and calorie-dense foods and beverages contribute to obesity
liver damage and eventual failure
excess fat accumulation in the liver
bone and joint disorders
excess pressure place don knees, ankles, and hip joints
reduced physical agility and increased risk of accidents and falls
excess weight impairs physical movement and gait
pulmonary disease and sleep disorders
excess weight stressing the lungs and pharynx
gender
females have more fat mass than males due to less lean body mass and reduced surface area
genetic predisposition
genetic factors may affect expenditure, deposition of adipose tissue or lean tissue, and the relative proportion of fat and carbs used by the body
vision problems
higher rates of cataracts and other eye disorders
menopause
hormonal changes result in increased abdominal fat deposition
menstrual irregularities and infertility
hormone imbalances; insulin resistance; increased oxidative stress
underwater weighing
hydrostatic weighing or hydrodensitometry -a common method to assess body composition
ethnicity
in some groups, higher body weight may be more socially acceptable, which may promote overeating
physical activity
includes activities of daily living and planned exercise; accounts for 15-35 percent of total energy expenditure
cardiovascular disease
increased LDL cholesterol and triglycerides; reduced HDL cholesterol; increased synthesis of blood clotting and inflammatory factors by enlarged adipose cells; potential for altered heart rhythm
surgical complications
increased anesthesia needs; greater risk of wound infection
gallstones
increased cholesterol content of bile
certain medications
increased hunger/appetite can be a side effect of many medications
hypertension
increased miles of blood vessels found in the adipose tissue, increased blood volume, and increased resistance to blood flow related to hormones made by adipose cells
overall kcal intake is more important than the specific distribution of carbs, fats, and proteins in the diet when it comes it losing weight
individuals can successfully lose weight with any combo (low carb-atkins, high carb- okinawan, moderate carb- mediterranian diet) -a defecit of kcal will lead to weight loss -a surplus of kcall will lead to weight gain
energy balance
intake equals outtake- calories in equals calories out
importance of portion control for controlling calorie intake
limit kcal intake by controlling portion sizes of each food in a meal
erectile dysfunction in men
low-grade inflammation caused by reduced function of the cells lining the blood vessels and impaired blood circulation
body mass index in metric and english
metric: kg over m squared english: lb over in squared X 703
pregnancy risks
more difficult delivery; increased birth defects and gestational diabetes; greater anesthesia needs
social and behavioral factors
obesity is associated with socioeconomic status; familial conditions, social networks, lifestyles, binge eating, availability of inexpensive "supersized" high fat food, patterns of leisure activities, increased screen time, smoking cessation, excessive alcohol intake
energy balance influence body weight
over a long period, dietary patterns consist with positive energy balance promote storage of excess body fat
infections
reduced immune system activity
region of residence
regional environmental and lifestyle differences, such as high-fat diets and sedentary lifestyles, especially in the South and Midwest, lead to higher rates of obesity
physical activity influence on body weight
sedentary behavior leads to positive energy balance and promotes body fat storage
increased hunger sensations
some individuals appear to have blunted satiety, which may be linked to various brain signals involved in food reward pathways
thermic effect of food on body weight
some obese individuals metabolize nutrients more efficiently, and thus expend fewer calories for digestion and absorption
bariatric surgery
surgical treatment for extreme obesity that restricts food intake, induces malabsorption of nutrients, or both -for people with BMI over 4o