MNT exam 3 (Energy Balance)
Terms in this set (108)
-measured in kilojoule (kJ) or kilocalories (kcal)
-historically determined by bomb calorimeter
-sources of information = nutrition facts label, restaurant brochures, food composition tables, dietary analysis software
24-hour energy expenditure
-resting energy expenditure
-thermic effect of food
Resting energy expenditure (REE)
-energy necessary to sustain life; keep vital organs functioning (heart, lungs, brain, liver, and kidneys)
-60-75% of EE, 1 kcal/kg body weight/ hour
-affected by lean body mass, sex, age, body temperature, energy restriction, endocrine system, and genetics
-basal energy expenditure (BEE) 10-20% lower than REE; impractical to measure
Thermic effect of food (TEF)
-measured for several hours postprandial (a measurable increase in energy expenditure over and above REE)
- This is the energy required to digest, absorb, metabolize, store, and eliminate nutrients
-10% of EE
-influenced primarily by the amount and macronutrient composition of the food consumed.
-large meals have greater TEF than small meals.
Physical activity EE
-this is the most highly variable component of 24-hour ee
-20-25% of EE
-Influenced by body weight, number of muscle groups used, intensity, duration and frequency of activity
-four levels of physical activity coefficients used in computing DRIs: sedentary; low active; active; very active
-Heavy people expend more energy than lighter-weight people because heavier people have a greater body mass to move.
What is indirect calorimetry used for?
for metabolic research or critically ill patients.
What does indirect calorimetry measure?
-inspired and expired air by minute ventilation
-EE is proportional to oxygen consumption and carbon dioxide production
What is Energy balance?
-a condition in which calories consumed equals those expended on a regular basis
-a fat cell; mostly triglyceride
-stores 90% of energy reserves
-Other functions: fills body crevices; provides insulation and protection; provides contour and cushion
The two kinds of adipose tissue
White fat (WAT)
Brown fat (BAT)
What does 24-hour energy expenditure consist of?
-Resting energy expenditure,
-Thermic effect of food
Where is REE greater?
in persons having a higher lean body mass
What is Basal energy expenditure? (BEE)
-The lowest rate of energy expenditure of an individual.
-measured in the morning, when subject is in postabsorptive state (no food consumed during previous 12 to 16 hours) and is comfortably lying motionless in a supine position in a thermally neutral environment.
Which macronutrient has the lowest TEF?
Which macronutrient has the highest TEF?
protein, due to the relatively high energy cost of processing the amino acids released from the proteins in food, including the synthesis of urea.
energy expenditure above and beyond the thermic effect of food and resting energy expenditure that is seen in response to overfeeding, traumatic injury, changes in hormonal status and exposure to a cold environment
Estimated Energy Requirement (EER)
the average dietary energy intake that is predicted to maintain energy balance in a healthy person of a defined age, gender, weight, height, and level of physical activity consistent with good health.
What leads to orexigenic responses?
decrease in energy intake and loss of body fat
what leads to anorexigenic responses?
modest increases in energy intake and increased body fat
Appetite is influenced by a number of signals to the brain that are primarily orchestrated by
what hormones are secreted by the pancreas and GI tract in response to hypothalamic stimulus?
insulin, glucagon, amylin, CCK, GLP-1, Peptide YY, and Ghrelin
Which hormones decrease appetite and food intake?
CCK, GLP-1, and Peptide YY
As plasma glucose level rises following a meal, the beta cells of the pancreas release
insulin and amylin, which decrease appetite and food intake.
What produces ghrelin
what does ghrelin stimulate?
a genetic disorder characterized by voracious appetite and massive obesity.
-A drop in ghrelin appears to decrease appetite and food intake, BUT IN PEOPLE WITH THIS DISORDER ghrelin levels are increased by as much as threefold or fourfold compared to individuals of similar age, sex, and BMI.
White adipose tissue
the cells of this tissue store triglycerides derived from dietary fats or those synthesized from carbohydrates and proteins through the process of lipogenesis.
-Triglyceride is stored within a single large droplet.
Where is brown adipose tissue primarily found?
this type of tissue is found primarily in fetuses, infants, and young children.
what is the primary function of BAT?
-maintains body temperature in human neonates and in hibernating animals by generating heat through a process known as diet-induced thermogenesis or non-shivering thermogenesis.
Is the adipocyte metabolically active?
Two hormones produced by adipose tissue that are involved in energy balance and fat storage
adiponectin and leptin
what does adiponectin do?
signals that the body has the capacity to store fat
what does leptin do?
signals that ample fat has been stored
Increased levels of adiponectin improve the body's sensitivity to:
insulin, which, in turn, enhances the body's capacity to store fat.
leptin levels increase as __________ increases
body fat mass
when adipocytes increase in size as they accumulate more triglyceride during periods when energy intake exceeds energy expenditure.
when adipocytes increase in number as immature adipocytes divide to produce more cells.
overweight (BMI: 25-29.9) and moderate obesity (30-34.9) are characterized by _________ of the adipocytes
as BMI approaches extreme obesity (BMI > 40), adipocytes reach their maximum size and then experience ____________
male and female obese considerations according to body fat percentages?
males = greater than or equal to 25%
females = greater than or equal to 33%
the most common approach to body composition analysis views the body as consisting of two different compartments: fat and fat free
what is used to define overweight in children and adolescents?
the U.S. centers for disease control and prevention (CDC) growth charts that provide the body mass index-for-age percentiles for males and females 2-20 years of age
what percentiles are considered overweight in children and adolescents?
greater than or equal to 85% and less than 95%
what percentiles are considered obese in children and adolescents?
greater than or equal to the 95th %tile
body fat distribution can be divided into two categories: _______________ and _____________
abdominal or central body fat distribution
lower body fat distribution
abdominal or central fat distribution
fat located primarily within the abdominal region of the body, both surrounding the organs of the abdomen (intra-abdominal or visceral fat) and located just under the skin around the waist (Subcutaneous fat).
where is abdominal fat distribution more often seen?
in males. It tends to give the body a shape resembling that of an apple.
it is commonly called android, meaning "manlike".
lower body fat distribution
fat located primarily in the lower region of the body, particularly within the hips and thighs, and tends to give the body a shape resembling a pear.
where is lower body fat distribution more often seen?
-is sometimes referred to as gynoid, meaning "womanlike"
In adults with a BMI between 25 and 34.9, risk of Type 2 diabetes, hypertension, dyslipidemia, coronary heart disease, and metabolic syndrome INCREASES when _________
waist circumference exceeds 40 inches in males and 35 inches in females
High risk waist circumference in males
High risk waist circumference in females
Waist to hip ratio (WHR)
calculated by dividing the WC measurement by the hip circumference measurement
-superior to BMI for identifying cardiometabolic risk
-superior to waist circumference in screening for diabetes, hypertension, and cardiovascular disease
Education is related to obesity in ________
women, but not men
"the age of caloric anxiety"
the combination of thin standard of beauty with fat ways of living
physiological consequences of overweight and obesity
-type 2 diabetes
-high blood pressure
how does obesity develop?
when the body's chronic energy intake exceeds its energy expenditure
obesogenic factors contributing to obesity
physical, social, cultural, and economical environments; food choices and eating behaviors; disordered eating patterns, sleep patterns, and changes in physical activity.
resulting from treatment.
-brought forth by a physician
-certain pharmacological agents are associated with weight gain
referring to those environments that both promote weight gain and act as barriers to weight loss
Two step process for treatment of overweight and obesity
what does the assessment process for treatment of overweight and obesity include?
-determining the degree of overweight and obesity by calculating BMI,
-measuring WC, WHR, and/or WHtR,
-Assessing for cardiovascular risk and/or other obesity-related comorbidities
-evaluating dietary and exercise habits,
-and determining the patient's readiness to lose weight.
What does the management process for treatment of overweight and obesity include?
-applying recommended therapies to both achieve and maintain weight loss and to prevent or treat other obesity-related disease risk factors.
Two most common classifications of obesity drugs:
-lipase inhibitors and appetite suppressants (anorectics)
work by blocking the action of pancreatic and gastric lipases, thereby reducing the digestion of triglyceride. Undigested triglyceride is not absorbed, does not provide energy to the body, and is eliminated in the feces.
Appetite suppressant (anorectic)
promote weight loss by acting on the central nervous system to decrease appetite and increase satiety, thus reducing food consumption and energy intake
Weight loss or bariatric surgery is reserved for __________
patients with a BMI greater than or equal to 40, or BMI greater than or equal to 35 with obesity-related comorbid conditions who are motivated to lose weight and who have not responded to behavioral treatment with or without pharmacotherapy.
4 types of bariatric surgery
-Laparoscopic adjustable gastric banding (LAGB)
-Laparoscopic vertical sleeve gastrectomy (LVSG)
-Roux-en-Y gastric bypass (RYGB)
-Duodenal Switch with biliopancreatic diversion (DS-BPD)
restrict the amount of food that enters the small intestine by creating a small gastric reservoir (or "pouch"), markedly limiting the volume of food and beverage that the stomach can hold and narrowing the outlet of the reservoir, which delays gastric emptying.
-Patient feels "full" sooner and the appetite is decreased.
-LAGB & LVSG
bypass various sections of the small intestine, resulting in the malabsorption of nutrients.
-DS-BPD is primarily malabsorptive but also has some restriction involved
combined restrictive and malabsorptive procedures
both reduces the volume of food and beverage that the stomach can hold and interferes with food digestion and nutrient absorption by bypassing part of the stomach and/or small intestine.
-because these procedures result in greater weight loss than the restrictive ones, they are regarded as better suited for very obese patients.
-RYGB is both malabsorptive and restrictive.
which is the most common weight loss procedure performed in the us?
RYGP, followed by LAGB
requires relatively large incisions into the abdominal cavity
sophisticated surgical instruments (including a light source and video camera) are inserted into the abdominal cavity through much smaller incisions.
Laparoscopic adjustable gastric banding (LAGB)
-inflatable silicone ring or band is laparoscopically introduced into the abdominal cavity and secured around the upper part of the stomach to create a small pouch with a narrow opening or stoma at the bottom. Food passes through this stoma into the rest of the stomach. The pouch restricts the amount of food that can be consumed at one time.
-This is the simplest and least invasive of the procedures because it does not require any stapling or cutting of the stomach.
Laparoscopic vertical sleeve gastrectomy (LVSG)
up to 85% of the stomach is surgically removed, leaving a narrow, tubular, banana-shaped portion of the stomach (a "gastric sleeve") between the esophagus and the duodenum
-restricts remaining stomach's holding capacity while preserving its functions, leaving the pylorus (the stomach's outlet) intact, and resulting in minimal, if any, nutrient malabsorption.
-detached section of the stomach is responsible for ghrelin production, which reduces serum levels of ghrelin, further enhancing weight loss
Roux-en-Y gastric bypass (RYGB)
-often considered the gold standard of surgical procedures due to its high degree of effectiveness and durability
-creates a small pouch at the top of the stomach, restricting food intake and quickly inducing satiety, and bypasses the remainder of the stomach, the duodenum, and the first part of the jejunum, reducing food digestion and nutrient absorption.
-The jejunum is cut and the distal end is surgically connected to the pouch, thus bypassing part of the small intestine and decreasing nutrient absorption.
most complicated bariatric procedure.
-less frequently performed, but results in the greatest weight loss.
-typically reserved for very obese patients who are at high risk for surgical complications due to severe obesity and/or other medical conditions linked to obesity.
Nutrition assessment for overweight and obesity
-client history and biochemical data
Nutrition diagnoses for overweight and obesity
-excessive fat intake
-food and nutrition related knowledge deficit
-disordered eating pattern
-undesirable food choices
-involuntary weight gain
Current guidelines recommend an inititial weight loss goal of 5%-10% of baseline weight within ____ months.
Weight loss tends to be greatest at how many months?
a 10% decrease in body weight results in 15% reduction in
24-hour energy expenditure
What is successful weight maintenance defined as?
a regain of weight that is less than 6.6 lb in 2 years and a sustained reduction in waist circumference of atleast 1.6 inches.
desired rate of weight loss
1-2 lb per week
How can you achieve a weight loss rate of 1-2 lb per week?
-reducing energy consumption by 500-1000 kcal/day (3500-7000 kcal/week) and increasing energy expenditure with moderate levels of PA.
Underweight in older adults
significant health risks and increasing problem especially among adults age 65 and older
-defined as BMI <18.5
What is cachexia primarily caused by?
catabolism as a result of increased metaboolic rate and protein breakdown.
health risks commonly associated with being underweight
anemia and nutrient deficiencies
-bone loss and osteoporosis,
-blood vessel diseases
-increased vulnerability to infection and disease
-delayed wound healing
age associated hormonal changes
-levels of glucocorticoids and catecholamines increase and
-levels of growth hormones and sex hormones decrease
-these changes result in an increase in timor necrosis factor-a, interleukins -1 and -6, and serotonin, which causes a decrease in appetite and may also contribute to muscle breakdown and nitrogen loss.
What is undernutrition in infants and children generally referred to?
Failure To Thrive (FTT)
Measurements that can indicate risk factors for FTT:
-weight-for-age below 5th percentile
-BMI for age <5th percentile
-length for age <5th percentile
-weight <75% of median weight for age, or
-weight <75% of median weight for length
What are eating disorders?
psychiatric conditions characterized by severe disturbances in eating behaviors that result in significant physiologic impairment.
DSM-5 recognizes which 3 disorders as eating disorders?
-Anorexia nervosa (AN)
-Bulimia nervosa (BN)
-Binge eating disorder (BED)
characterized by excessive dieting, severe weight loss, and distorted body image with a pathological fear of being fat
-amenorrhea does not need to be present to diagnose AN
Two subtypes of Anorexia nervosa
restricting type and binge eating/purging type
Lose weight through dieting, fasting, or excessive exercise and do not regularly engage in binge eating or any of the compensatory weight-loss behaviors such as purging.
Binge eating/purging AN
engage in regular binge eating and/or purging.
compensatory weight loss behaviors include self-induced vomiting, fasting, excessive exercise, and misuse of laxatives, diuretics, and enemas.
characterized by frequent episodes of binge eating followed by inappropriate behaviors such as self-induced vomiting to avoid weight gain.
-an episode of binge eating must be characterized by consumption during a relatively short period of time (e.g., within a 2-hour period) of an amount of food that is definitely larger than what most people would ordinarily eat in a similar situation, coupled with a sense of a lack of control on the part of the patient.
-is diagnosed when binge eating and compensatory behaviors occur atleast onve per week over a period of three months
binge eating disorder (BED)
recurring episodes of eating significantly more food in a short period of time than most people would eat, with episodes marked by feelings of lack of control
eating disorders common features
-disturbed body image
-perceive self as obese
-intense fear of weight gain and obesity
-relentless drive to lose weight
Callus on back of hand from stimulating gag reflex is a skin and extremities physical complication of _____
No single therapy is most successful with patients with AN; may combine approaches
Cognitive behavioral therapy is most successful with patients with BN and BED
Primary treatment goal with AN?
Restoring the patient's weight
dietitian role for BN patients?
to develop an eating plan to normalize patient's eating habits
nutrition therapy for BED depends on
patient's specific abnormal eating behaviors