SM_191b: Starvation and Metabolic Adaptation

Question 1

Starvation is ___

Answer 1

Starvation is physiologic state of negative energy ± protein balance

Question 2

Starvation-associated malnutrition or protein energy malnutrition is ___

Answer 2

Starvation-associated malnutrition or protein energy malnutrition is prolonged deficit of energy and/or protein, which results in clinical manifestations

Question 3

Disease associated malnutrition (cachexia) occurs with ___, is characterized by ___, and is induced by ___

Answer 3

Disease associated malnutrition (cachexia) occurs with illness, is characterized by increased protein catabolism, and is induced by inflammatory cytokines

Question 4

Caloric restriction is ___

Answer 4

Caloric restriction is volitional reduction in energy intake (below needs), with adequate intake of protein and micronutrients

Question 5

Sarcopenia is ___

Answer 5

Sarcopenia is loss of muscle mass associated with aging

Question 6

Total energy expenditure = ____ + ____ + ____

Answer 6

Total energy expenditure = basal metabolic rate + thermic effect of food + energy expenditure of physical activity

(TEE = BMR + TEF + EEPA)

Question 7

Total energy expenditure (TEE) is ___

Answer 7

Total energy expenditure (TEE) is energy expended by an individual in one day

Question 8

Basal metabolic rate is ____

Answer 8

Basal metabolic rate is energy expended for vegetative functions of the body (respiration, body temperature regulation, etc)

Question 9

Thermic effect of food is ___

Answer 9

Thermic effect of food is increase in energy expenditure observed after the consumption of a meal

Question 10

Energy expenditure of physical activity is ____

Answer 10

Energy expenditure of physical activity is energy used during daily physical activity (exercise + non-exercise)

Question 11

Total energy expenditure consists of ____, ____, and ____

Answer 11

Total energy expenditure consists of basal metabolic rate (60%), energy expenditure of physical activity (30%), and thermic effect of food (10%)

Question 12

Determinants of basal metabolic rate are ___, ___, ___, ___, and ___

Answer 12

Determinants of basal metabolic rate are body composition, age, gender, nutritional status, and health status

Question 13

Most usable energy stores are ____

Answer 13

Most usable energy stores are fatty acids

(then protein, then glycogen)

Question 14

Fuel metabolism during starvation first involves ____, then ____, then ____

Answer 14

Fuel metabolism during starvation first involves exogenous, then glycogen, the gluconeogenesis

Question 15

During starvation, origins of new blood glucose are ___ and ___

Answer 15

During starvation, origins of new blood glucose are liver (50-80%) and kidneys (20-50%)

Question 16

During starvation, substrates for gluconeogenesis are ____, ____, ____, ____, and ____

Answer 16

During starvation, substrates for gluconeogenesis are lactate, pyruvate, alanine, glycerol, and glutamine (used by kidney)

Question 17

During starvation, other fuel sources are ____ and ____

Answer 17

During starvation, other fuel sources are free fatty acids and ketone bodies

Question 18

In fuel usage by tissue (late starvation), brain mainly uses ____

Answer 18

In fuel usage by tissue (late starvation), brain mainly uses ketone bodies

Question 19

Describe changes in energy expenditure during starvation

Answer 19

Changes in energy expenditure during starvation

• TEE: decreased
• BMR: decreased
• TEF: decreased
• EEPA: decreased

Question 20

Ghrelin and glucagon ____ during starvation

Answer 20

Ghrelin and glucagon increase during starvation

Question 21

Leptin, insulin, T3 / T4, LH, FSH, estrogen, and testosterone ___ during starvation

Answer 21

Leptin, insulin, T3 / T4, LH, FSH, estrogen, and testosterone decrease during starvation

Question 22

____ occurs after weight loss

Answer 22

Metabolic adaptation occurs after weight loss

Question 23

During weight loss in obesity, ____, ____, and ____ are decreased

Answer 23

During weight loss in obesity, leptin, energy expenditure, and T3 / T4 are decreased

Question 24

During weight loss in obesity, ____ and ____ are increased

Answer 24

During weight loss in obesity, ghrelin and muscular efficiency are increased

Question 25

\_\_\_\_ is modified after weight loss in obesity

Answer 25

Neural activity on brain fMRI in response to visual food cues is modified after weight loss in obesity

Question 26

After weight loss, gap between ____ and ____ is wider

Answer 26

After weight loss, gap between increased hunger and decreased energy expenditure is wider

Question 27

Describe metabolic and hormonal changes of weight loss in obesity that are reversed with leptin

Answer 27

Reversed with leptin? Deecreased * Leptin: yes * Energy expenditure: yes * T3 and T4: yes Increased * Ghrelin: no * Muscular efficiency Modified * Neural activity on brain fMRI in response to visual food cues: yes

Question 28

Metabolic adaptation to weight loss ___ long-term persistence

Answer 28

Metabolic adaptation to weight loss has long-term persistence

Question 29

Describe metabolic responses to starvation

Answer 29

Metabolic responses to starvation * Decreased energy expenditure * Use of alternative fuelds (free fatty acids and ketone bodies) can reduce protein catabolism * Intake of minimal dietary carbohydrate (100 g) can suppress protein catabolism and gluconeogenesis

Question 30

Describe metabolic responses to illness

Answer 30

Metabolic responses to illness * Increased energy expenditure * Markedly increased protein catabolism * Glucose does not suppress protein catabolism

Question 31

In illness, basal metabolic rate ____ due to \_\_\_\_, \_\_\_\_, and \_\_\_\_

Answer 31

In illness, basal metabolic rate increases due to catecholamine / sympathetic nervous system stimulation, fever, and inflammation / cytokines (BMR may increase by 30-100%)

Question 32

In illness, protein catabolism ____ due to \_\_\_\_, \_\_\_\_, and \_\_\_\_

Answer 32

In illness, protein catabolism increases due to inflammation and cytokines, increased cortisol, and insulin resistance

Question 33

Which increases protein catabolism the most? A. Sepsis B. Hysterectomy C. Hip fracture D. Major burn E. Starvation

Answer 33

Which increases protein catabolism the most? A. Sepsis B. Hysterectomy C. Hip fracture **D. Major burn** E. Starvation

Question 34

\_\_\_\_ and ____ cause malnutrition

Answer 34

Starvation and disease cause malnutrition

Question 35

Marasmus involves a deficit of \_\_\_\_

Answer 35

Marasmus involves a deficit of calories

Question 36

Describe marasmus

Answer 36

Marasmus: deficit of calories * Very low body weight * Wasted appearance with loss of muscle and fat * Liver function is usually normal * ± hypoalbuminemia * Dry, inelastic skin

Question 37

Kwashiorkor involves a deficit of \_\_\_\_

Answer 37

Kwashiorkor involves a deficit of protein

Question 38

Descrube kwashiorkor

Answer 38

Kwashiorkor: deficit of protein * Low or normal body weight * Edema may mask weight loss * Distended abdomen * Fatty liver / liver dysfunction * Marked hypoalbuminemia * Skin and hair changes

Question 39

Flag sign, flaky pain rash, and depigmentation of hair occur in \_\_\_

Answer 39

Flag sign, flaky pain rash, and depigmentation of hair occur in kwashiorkor (flag sign: alternating areas of hypo and hyperpigmentation of hair)

Question 40

8 month old infant fed on demand with rice, milk, bananas, and sweet potatoes for the past 4 months may have \_\_\_, \_\_\_, \_\_\_, and \_\_\_

Answer 40

8 month old infant fed on demand with rice, milk, bananas, and sweet potatoes for the past 4 months may have normal body weight, edema, ascites, and desquamative rash

Question 41

Pathogenesis of kwashiorkor may involve \_\_\_\_, \_\_\_\_, and \_\_\_\_

Answer 41

Pathogenesis of kwashiorkor may involve primary protein deficiency, inadequate antioxidant capacity, and gut microbiome

Question 42

Malnutrition can result in ___ in childhood

Answer 42

Malnutrition can result in stunted growth in childhood

Question 43

Describe physiologic changes in malnutrition

Answer 43

Physiologic changes in malnutrition * Hypothermia * Cardiovascular: hypotension, bradycardia, and decreased cardiac output * Pulmonary: decreased respiratory muscle mass and function, decreased respiratory drive * Endocrine: hypogonadotrophic hypogonadism, osteoporosis * GI: delayed gastric emptying * Hematologic: anemia, leukopenia * Neurologic: decreased volume of gray matter, decreased sympathetic activity

Question 44

Behavioral changes seen during starvation are \_\_\_\_, \_\_\_\_, \_\_\_\_, \_\_\_\_, and \_\_\_\_

Answer 44

Behavioral changes seen during starvation are * Preoccupation with food * Hoarding and stealing food * Abnormal taste preferences * Binge eating * Depression, apathy, irritability, and other personality changes

Question 45

Oral nutrition involves ____ or \_\_\_\_

Answer 45

Oral nutrition involves whole foods or supplements

Question 46

Nutrition support to patients who cannot or will not eat involves ____ or \_\_\_\_

Answer 46

Nutrition support to patients who cannot or will not eat involves enteral nutrition or parenteral nutrition

Question 47

Enteral nutrition is via the \_\_\_

Answer 47

Enteral nutrition is via the gut (if the gut works, use it)

Question 48

Parenteral nutrition formulas contain \_\_\_\_, \_\_\_\_, \_\_\_\_, and \_\_\_\_

Answer 48

Parenteral nutrition formulas contain water, macronutrients (dextrose, amino acids, emulsified lipids), electrolytes (minerals), and vitamins / trace elemtns

Question 49

Total parenteral nutrition \_\_\_

Answer 49

Total parenteral nutrition meets energy and protein needs * High osmolality requires administration into vena cava via a central line due to risk of phlebitis

Question 50

Peripheral parenteral nutrition usually \_\_\_\_

Answer 50

Peripheral parenteral nutrition usually cannot meet energy or protein needs * Lower osmolality so can be infused through smaller peripheral veins

Question 51

Refeeding syndrome occurs when \_\_\_\_

Answer 51

Refeeding syndrome occurs when food is introduced too quickly after a period of malnourishment * Shifts in electrolytes can cause severe complications: seizures, heart failure, and comas