nutrition test 6
what happens to adipocytes with weight loss/gain/age
- Adipocytes shrink in size with weight loss but the number of cells does not decrease. - After weight loss, small fat cells are readily filled with excess energy. - Fat growth and production of cells continue throughout life, but hyperplasia slows with age.
Growth of fat cells (adipocytes) occurs in two ways.
- Can expand to store more fat (hypertrophy) - Once filled to capacity, stimulate the production of more fat cells (hyperplasia)
Individuals who are underweight are more likely to be at greater risk for:
- Irritability - Anger - Depression
leptin: what happens with drop in leptin
- Leptin ▪ Drop in leptin when adipose tissue shrinks stimulates hunger
neuropeptide Y: where is it produced? what is it activated by?
- Neuropeptide Y ▪ Produced in the hypothalamus and activated by ghrelin ▪ Stimulates hunger and LPL activity
overweight/obese have how much fat in adipocytes
- Overweight or obese adults are thought to have larger adipose cells (hold 0.6 to 1.2 micrograms of fat each).
Kilocalories consumed are determined using:
1) Bomb calorimeter: Measures kilocalories in foods and beverages - Results must be adjusted for the physiological fuel values. - Physiological fuel values reflect the actual kilocalories transformed into energy in the body. 2) Nutrition analysis software or food composition tables - Carbohydrate and protein: 4 kilocalories/gram - Fat: 9 kilocalories/gram - Alcohol: 7 kilocalories/gram
2 ways we measure energy expenditure
1) Direct calorimetry measures energy expenditure by assessing body heat loss within a metabolic chamber. 2) Indirect calorimetry estimates energy expenditure by measuring oxygen consumed and carbon dioxide produced with a metabolic cart.
Two types of fat make up total body fat.
1) Essential fat ▪ Essential for the body to function ▪ Women have more essential fat (12 percent) than men (3 percent). 2) Stored fat ▪ Found in adipose tissue ▪ Subcutaneous fat is located under the skin. ▪ Visceral fat is stored around the organs in the abdominal area. - Insulates the body from cold temperatures - Protects and cushions internal organs
obesity environmental factors
1) lack of time -most calorie intake is from foods eaten away from home -dining out=higher BMI, less likely to choose fruits and vegetables 2) abundant food supply -people eat more when given larger portions/plate 3) less manual labor in jobs, more driving, more time in front of screens
bulimia diagnostic criteria (5)
1) recurrent episodes of binge eating. binge eating is characterized by both eating in a discrete amount of time (ex. 2 hours) large amount of food, AND lack of control during episode 2) Recurrent inappropriate compensatory behavior in order to prevent weight gain (purging) 3) The binge eating and compensatory behaviors both occur, on average, at least twice a week for 3 months 4) Self-evaluation is unduly influenced by body shape and weight 5) The disturbance does not occur exclusively during episodes of anorexia nervosa
physical activity factors
1) sedentary phys activity factor men: 1.00, women: 1.00 2) Low level of activity (walking approximately 2 miles per day at 3 to 4 miles per hour) men: 1.11 women: 1.12 3) Active (walking approximately 7 miles per day at 3-4 miles per hour) men: 1.25 women: 1.27 4) Very active (walking approximately 17 miles per day at 3-4 miles per hour) men: 1.45 women: 1.48
how to lose weight healthfully
1) strive for reasonable weight loss -10% of body weight over 6 months 2) calories count: reduce portion sizes, increase calories burned -more fruit/veg/fiber, less mindless eating 3) add protein and fat to meals -lean protein promotes satiety 4) fat slows movement out of stomach -healthy fats in moderation -limit saturated fats 5) increase physical activity -60-90 minutes of moderate-intensity exercise -spot reducing doesn't work -cardio and strength training 6) break bad habits -changing behaviors that promote weight gain -keep food log -control environmental factors and manage stress
Other specified feeding or eating disorder (OSFED)
A pattern of disordered eating that does not meet the criteria for anorexia nervosa, bulimia nervosa, or binge eating disorder includes orthorexia and night eating syndrome
night eating syndrome
A type of eating, sleeping, and mood disorder A person consumes a majority of daily kilocalories after the evening meal and wakes up during the night to eat. Characteristics of the individual ▪ Typically does not have an appetite during morning hours ▪ Low self-esteem, depression, and stress ▪ May feel guilty, ashamed, or embarrassed while eating at night, as well as the next morning ▪ Common among young adults 18 to 30 years old
adiponectin
Adipocytes secrete the hormone adiponectin. - Improves the body's response to insulin - Reduces fat accumulation in the liver and muscle - Enhances energy expenditure - Lower in obese individuals and type 2 diabetics than in lean people • Some individuals store more fat with excess energy intake. • Genes may cause different rates of thermogenesis
adipose tissue and neg/pos energy balance
Adipose tissue releases fat during negative energy balance. - Adipocytes shrink and weight is lost. In positive energy balance, fat accumulates and adipose cells expand
factors that affect basal metabolism: race
African Americans have BMRs that are about 10 percent lower than those of Caucasians.
obesity spending: how much spent on weight loss solutions, how much US healthcare system spends annually
Americans spend over $60 billion annually on weight-loss solutions. The U.S. health care system spends $190 billion annually on obesity-associated medical conditions.
energy imbalance
An energy imbalance results in weight gain or loss
factors that affect basal metabolism: hormones
An increase in thyroid hormone increases BMR, whereas too little of this hormone lowers B MR. Hormone fluctuations during a woman's menstrual cycle lower BMR during the phase before ovulation.
orthorexia
An obsession with "healthy or righteous eating" Often begins with a person's desire to live a healthy lifestyle Characteristics of the individual ▪ Spends most of his or her time thinking about food and how it was prepared, processed, and overall health benefits of the food ▪ Typically does not obsess over calorie content of foods Eliminates foods based on learning about a negative health effect from eating the food Restrictive nature can develop into anorexia
how many adipocytes does the average adult have, how much fat does each hold
Average adult has 30 to 50 billion adipocytes, which hold 0.4 to 0.5 micrograms of fat each.
why is BMI inacurrate?
BMI is not a direct measure of percent of body fat. Not accurate for everyone: -athletes and some individuals: BMI > 25 but have high muscle mass and low body fat - Older adults with chronic weight loss: May have healthy BMI but significant loss of muscle mass and depletion of nutrient stores - Individuals less than 5 feet in height may have a high BMI, but not be unhealthy
estimations of total energy expenditure
Based on age, gender, height, weight, and level of physical activity Estimated energy requirement (EER)
factors that affect basal metabolism: temperature
Being very cold or very hot can increase BMR. The change is minimal if clothing or air temperature are adjusted.
what is body composition and how is it assessed?
Body composition: The ratio of fat tissue to lean body mass (muscle, bone, and organs) - Usually expressed as percent body fat - Important for measuring health risks associated with too much body fat
factors that affect basal metabolism: caffeine
Caffeine can raise BMR, but only slightly when consumed regularly in moderate amounts.
binge eating disorder
Characterized by recurrent episodes of binge eating without purging or regard to physiological cues May eat for emotional reasons ▪ Leads to out-of-control feeling while eating and physical and psychological discomfort after eating -May eat in secret and feel ashamed about the behavior Health consequences ▪ May cause high blood pressure, high cholesterol, heart disease, type 2 diabetes, and gallbladder disease
how to get a better estimation of body composition?
Combine indirect measurements to get a better estimate of body composition
disordered eating: definition, examples
Disordered eating describes abnormal and potentially harmful eating patterns. Ex. refusing to eat, compulsive eating, binge eating, restrictive eating, vomiting after eating, abusing diet pills/laxatives/diuretics
health consequences of anorexia
Electrolyte imbalances Drop in heart rate and blood pressure, weakness and fatigue, hair loss Slowing of the digestive process Inadequate nutrient intake and possible deficiencies Inability to regulate internal body temperature
negative energy balance
Energy expended is more than energy intake - Food intake is reduced, more energy is expended through exercise, or both - Results in weight loss ▪ Fat loss ▪ Muscle loss ▪ Loss of glycogen or water calories out>calories in
Body processes and physical activity result in energy out.
Energy needed throughout the day will vary for each individual based on: ▪ Basal metabolism ▪ Thermic effect of food (TEF) ▪ Thermic effect of exercise (TEE) ▪ Adaptive thermogenesis
gynoid obesity
Excess fat around the thighs and buttocks - More common in women than men pear shaped: more below waist
obesity and distribution of body fat: upper body
Excess subcutaneous and visceral fat stored in the upper body (abdomen and waist); referred to as central or android obesity -Waist circumference > 35 inches in women -Waist circumference > 40 inches in men
obesity and distribution of body fat: lower body
Excess subcutaneous fat stored in the lower body (hips, buttocks, thighs); referred to as gynoid obesity -Waist-to-hip ratio < 0.8 in women -Waist-to-hip ratio < 0.95 in men
factors that affect basal metabolism: age
For adults, BMR declines about 1-2 percent per decade after the early adult years but it increases by 15 percent during pregnancy. For children, BMR increases during times of rapid growth such as infancy and adolescence.
estimations of resting metabolic rate (RMR)
Harris-Benedict equation: based on gender, height, weight, and age ▪ Requires an activity factor to determine TDEE
height-weight vs BMI
Height and weight tables can provide a healthy weight range. - Provide a recommended desirable weight range for a given height based on gender and frame size Problematic because they do not represent population as a whole, original data was not standardized, and were constructed with the assumption that weight is associated with body fat Most health experts use body mass index rather than height-weight tables to determine healthy weight.
factors that affect basal metabolism: stress
Hormones such as epinephrine, which are released during emotional stress, increase BMR. Physiological stress on the body caused by injury, fever, burns, and infections also causes the release of hormones that raise BMR. Heat loss from the body through wounds, as well as the response of the immune system during infection, increase BMR.
where is hunger controlled? ghrelin: where is it secreted, what does increased production stimulate, which individuals have more?
Hunger is controlled by the lateral hypothalamus. - Ghrelin ▪ Secreted by the stomach ▪ Increased production tells the hypothalamus the body needs energy. ▪ Stimulates hunger during fasting or on a low-kilocalorie diet ▪ Lean individuals have higher ghrelin levels.
obesity is a disease: benefits and downsides
In 2013, the American Medical Association declared obesity a "disease." Benefits to declaring it a disease - Provides a clear warning of the health hazards of being overweight - May make it easier for individuals to get insurance coverage for treatment - More research funding may be allocated to addressing the obesity problem in the United States Downside to declaring it a disease - It may encourage more use of drugs and medical procedures to address the epidemic rather than encouraging lifestyle changes
obesity statistics: 1960's vs today, % of adults and children
In the early 1960s, fewer than 32% of Americans were overweight. Today, 67% of Americans are overweight. More than 33% of adults and 16% of children are obese.
when does waist circumference indicate health risk in men and women
Increased health risk with a normal BMI if: ▪ > 35 inches in women ▪ > 40 inches in men
why is it important to know your energy expenditure?
Knowing your energy expenditure provides the basis for either establishing energy balance to maintain weight or creating an energy imbalance to gain or lose weight.
which hormones control the size of fat cells, heavier people have more of which, differences in men and women
LPL=inc lipogenesis HSL=stimulates lipolysis heavier people have more LPL activity Men: LPL more active in visceral, abdominal fat cells - Women: LPL activity higher in hips and thighs
factors that affect basal metabolism: lean body mass
Lean body mass, which is mostly muscle mass, is more metabolically active than fat tissue, so more kilocalories are needed to maintain it. Athletes who have a large percentage of lean body mass due to their increased muscle mass have a higher BMR than individuals who aren't athletic
Air displacement plethysmography (BodPod)
Measures air rather than water displacement - Accurate within 3 percent
skinfold caliper
Measures fat in various locations - Can be accurate if applied by a trained technician Waist circumference is a quick indicator of health risk. It indicates where fat is located, not the percentage of body fat.
Bioelectrical impedance analysis (BIA)
Measures resistance to low energy current as it travels through muscle and body fat - Not as accurate as body density tests
essential fat men and women
Men: 3% Women: 12%
hydrostatic weighing
Method to assess body volume by underwater weighing - One of the most accurate assessment tools; 2 to 3 percent margin of error
being overweight and discrimination
More likely to be denied job promotions and raises Obese females are less likely to be accepted into college, especially higher ranked colleges. People perceive them as lazy or weak-willed. Obese people have higher rates of suicide and are more likely to use drugs and alcohol.
correlation b/w diabetes/metabolic syndrome and obesity
More than 80% of people with type 2 diabetes are overweight. Metabolic syndrome is associated with central obesity
Dual-energy X-ray absorptiometry (DEXA)
Most accurate method; margin of error 1 to 4 percent - Uses two low-energy X-ray beams to measure bone density and body mass
factors that affect basal metabolism: drugs
Nicotine may increase BMR.* Stimulant drugs such as amphetamine and ephedrine increase BMR. Smoking is not a weight-management strategy. Some people may think that replacing snacks with cigarettes helps them stay slim, but the health risks associated with smoking, such as lung cancer, heart disease, and stroke, make it a foolish habit. Anyone concerned about weight gain when quitting smoking can minimize the chances of this with exercise.
NEAT
Non-exercise activity thermogenesis: Energy expended from activities not considered exercise
nutrigenomics and epigenetics
Nutrigenomics: The study of how your genetic makeup interacts with your diet Epigenetics: The changes that may occur in gene activity and gene expression without altering DNA sequence Food and nutrients are a factor that can activate or repress certain genes.
obesity and health risk
Obese individuals have a 50 to 100 percent higher risk of dying prematurely than those at a healthy weight.
being overweight increases the risk of which diseases?
Overweight and obesity are associated with increased risk of heart disease, hypertension, stroke, gallstones, hyperlipidemia, sleep apnea, and reproductive problems. Increases risk of certain cancers, including colon, breast, endometrial, and gallbladder cancer
positive energy imbalance
Positive energy balance: Energy intake is more than energy expended ▪ Weight gain from increased muscle mass, increased adipose tissue, or both ▪ Periods of growth: Pregnancy, childhood, and adolescence calories in>calories out
BED: definition, binge eating is char by what, binge eating episodes ass with what, does not occur along with what
Recurrent and persistent episodes of binge eating. 1) Binge eating characterized by both of the following: -eating, in a discrete amount of time, an amount of food larger than nl -lack of control over eating during episode (cannot stop eating) 2) Binge eating episodes are associated with three (or more) of the following: eating more quickly eating until uncomfortably full eating large amounts while not feeling physically hungry eating alone due to embarrassment about how much u are eating feeling disgusted after overeating 3)Marked distress regarding binge eating is present 4) The binge eating occurs, on average, at least once a week for three months 5) The binge eating is not associated with the recurrent use of inappropriate compensatory behavior (for example, purging) and does not occur exclusively during the course of anorexia nervosa, bulimia nervosa, or avoidant/ restrictive food intake disorder
factors that affect basal metabolism: genes
Research suggests that genes may affect BMR, as individuals within families have similar metabolic rates.
anorexia diagnostic criteria (3)
Restriction of energy intake relative to requirements leading to a significantly low body weight in the context of age, sex, developmental trajectory, and physical health Intense fear of gaining weight or becoming fat, even though underweight Disturbance in the way one's body weight or shape is experienced, excessive influence of body weight or shape on self-esteem or denial of the seriousness of the current low body weight
satiety: where is it triggered? CKK and peptide YY: where secreted, leptin, which macronutrient promotes satiety
Satiety is triggered by the ventromedial nucleus. - Cholecystokinin (CKK) and peptide YY (PYY) ▪ Secreted by the small intestine to stimulate satiety - Leptin ▪ Produced in adipose tissue ▪ Decreases hunger and food intake ▪ Regulates amount of fat stored ▪ Decreases with weight loss and intake of certain vitamins and minerals • Certain macronutrients, especially protein, promote satiety and reduce food intake
factors that affect basal metabolism: starvation
Starvation and fasting for more than about 48 hours lower BMR.
Being underweight increases health risks
Symptomatic of malnutrition, substance abuse, or disease Higher risk of anemia, osteoporosis and bone fractures, heart irregularities, and amenorrhea Correlated with depression and anxiety, inability to fight infection, trouble regulating body temperature, decreased muscle strength, and risk of premature death
T/F: Some individuals with anorexia exercise excessively to control weight
T
TDEE (total daily energy expenditure)
TDEE: Total kilocalories needed to meet daily energy requirements TEE (adaptive thermogenesis and NEAT)=20-35% BMR=50-70% TEF=10%
factors that affect basal metabolism: body size
Taller individuals have a higher BMR due to increased surface area compared with shorter individuals. More surface area means more heat lost from the body, which causes the metabolism rate to increase to maintain the body's temperature.
bulimia nervosa health consequences
Tears in the esophagus Tooth decay and gum disease from stomach acid Electrolyte imbalances Dehydration and constipation Impaired normal bowel function through laxative use Depression and low self-esteem
TEF
Thermic effect of food: Energy used to process the macronutrients and extract kilocalories from food 10% of calories in food consumed is used for TEF ▪ Meals high in protein have greater TEF than those high in carbohydrate, which have greater TEF than those high in fat. - TEF is influenced by type of nutrients consumed, composition of a meal, alcohol intake, age, and athletic training status
BMI values: underweight, normal weight, overweight, obesity, severe obesity
Underweight < 18.5 Normal weight 18.5-24.9 Overweight 25-29.9 (also defined as being 10-15 pounds above a healthy weight) Obesity 30-39.9 Severe obesity > 40
maintaining healthy weight: BMI range, why is it important
Weight management is maintaining body weight within a healthy range (BMI of 18.5 to 24.9). Healthy weight is a body weight that does not increase risk for developing weight-related health problems or diseases. Healthy weight lowers risk for chronic disease
factors that affect basal metabolism: gender
Women have less lean body mass, and typically have a higher percentage of body fat than men. This results in women having a BMR up to 10 percent lower than men's. Women also tend to have a smaller body size.
where is most body fat stored?
adipose tissue
how can genes influence hunger, satiety and insulin response
altered genes can determine hormonal response to food (hunger/satiety) genes receive signals that can turn them on or off (by DNA methylation and histone modifications) epigenetic alteration and SNPs are believed to affect how people respond to food intake genes are transcribed through transcription factors that are activated by cellular signaling cascades
central obesity
android obesity Excess visceral fat in the abdomen Increases risk for heart disease, diabetes, and hypertension Visceral fat releases fatty acids that travel to the liver, causing insulin resistance, increased LDL, decreased HDL, and increased cholesterol. apple shaped (men): more above waist
BMR
basal metabolic rate: Amount of energy spent to meet the body's basic physiological needs influenced by lean body mass, age, gender, body size, genes, ethnicity, emotional/physical stress, thyroid hormone less, nutritional state, environmental temperature and caffeine and nicotine intake. BMR is difficult to measure, so resting metabolic rate (RMR) is often used.
BMI
body mass index: calculates body weight in relation to height. - Useful screening tool to determine an individual's risk for disease
BAT
brown adipose tissue is another type of fat tissue made up of specialized fat cells. - Contain more mitochondria and rich in blood - Function is to generate heat slide 25: white has more triglycerides, brown has more mitochondrion and more numerous, smaller triglyceride
energy balance
calories in = calories out weight will be stable proper balance between energy expended and food intake
BMI and waist circumference to determine health risk extremely high risk: very high risk: high risk: increased risk: low risk:
extremely high risk: BMI 40+ and high waist circumference very high risk: BMI 30-39.9 and high waist circumference high risk: BMI 25-29.9 and high waist circumference OR BMI 30-34.9 and low waist circumference increased risk: 25-29.9 and low waist circumference low risk: BMI under 25
is body composition assessed indirectly or directly?
indirectly
appetite
is the desire to eat food whether or not there is physical hunger. - Triggered by factors such as time of day, social occasions, emotions, or the sight or smell of food
how may being underweight be unintentional?
malabsorption associated with diseases such as cancer, inflammatory bowel disease, or celiac disease Also may be due to certain medications, smoking, and substance abuse
Desirable fatness for good health in Men and Women
men: 10-20% body fat women: 16-26% body fat
obesity and BMI
men: >25 kg/m women: 30 kg/m
overfat in men and women
men: >25% body fat women: >30% body fat
eating disorders: definition, most common in which group, increasing in which groups
psychological illnesses diagnosed by meeting specific criteria that include disordered eating behaviors and other factors. - Most common in young adults and adolescents, predominantly in white upper-middle- and middle class families - Increasing among males, minorities, and other age groups
ED treatment
requires multidisciplinary team approah (psych/medical/nutrition professionals) - As some eating disorders can be life-threatening, a physician should closely monitor treatment. -registered dietitian nutritionist can help with meal planning, food journals, identifying triggers, recognizing hunger and fullness cues --Full recovery from eating disorders is possible and most successful when the disorder is treated in the early stages
factors involved in energy balance
slide 17 energy in=mainly carbs, some fat and proteins, smallest amount alcohol energy out=mainly basal metabolism, then TEE (includes thermogenesis and NEAT), then smallest amount is TEF
Energy is Used for Adaptive Thermogenesis
the body's regulation of heat production is influences by changes such as stress, temperature or diet-all result in change in metabolism Some researchers think it explains why two people can have similar diets and exercise patterns but differing body compositions
what controls feeding?
the brain and hormones
satiety
the feeling of ''fullness'' produced by the consumption of food. hormones: insulin, leptin, peptide YY, cholecystokinin
hunger
the physical sensation associated with the need or intense desire for food. hormones: neuropeptide Y, ghrelin, drop in leptin
genetic set point theory
theory that the body will fight to remain a specific weight and opposes attempts at weight loss given rapid rise in weight in US, theory either isn't true or set point is easily overridden Populations which are genetically prone to being overweight or obese can overcome their genetic predisposition by engaging in regular exercise and eating healthy.
TEE
thermic effect of exercise: Increase in muscle contraction that occurs during physical activity - Amount of kilocalories you need for TEE depends on the activity performed, duration of activity, and how much you weigh.
obesity % of body weight
women: >32% men: >25%
