Apetite regulation Flashcards
What is the formula that determines weight gain or loss?
- EI > EE = weight gain
- EI < EE = weight loss
What are the components of energy expenditure?
Resting bodily function and PA & exercise
Is the decision to eat food a simple physiological process?
No, it is complex with psychological and environmental components
What are the four components of the physiological regulation of energy balance?
- Afferent peripheral hormonal signaling
- Central integration
- Efferent signaling
- Behavioral change
Define Orexigenic
Appetite-stimulating
Define Anorexigenic
Appetite-inhibiting (satiety)
List peripheral appetite regulating hormones that are Orexigenic
Ghrelin
Name some anorexigenic hormones released from the periphery.
PYY, Insulin, GLP-1, Leptin, CCK, PP
Where is Ghrelin produced?
Stomach
Where is PYY produced?
Intestines
Where is Insulin produced?
Pancreas
Where is Leptin produced?
Adipose tissue
What are the exercise intensity classifications based on %VO2max?
- Low-intensity: <50% VO2max
- Moderate-intensity: 50-70% VO2max
- Vigorous-intensity: >70% VO2max
What is HIIT?
High-intensity Interval Training, Near maximal
What is SIT?
Sprint Interval Training, All out efforts
What should energy intake match to maintain weight?
Energy expenditure (EE)
How does exercise affect appetite and energy intake?
Exercise can decrease appetite and affect subsequent energy intake, depending on the characteristics of the exercise
List potential mechanisms through which exercise affects appetite.
Fatty acids, hypoxia, sympathetic nervous system, GI motility, inflammation, blood glucose, lactate, and the presence of food in your stomach
What effects do MICT and SIT have on ghrelin levels?
MICT has no effect on ghrelin, while SIT decreases ghrelin
What type of exercise leads to exercise-induced appetite suppression?
SIT (Sprint Interval Training)
What is the relationship between lactate and ghrelin levels?
As lactate levels increase, ghrelin levels decrease
What type of exercise increases lactate and reduces appetite?
SIT (Sprint Interval Training)
How does sodium bicarbonate affect lactate production during exercise?
It buffers H+ ions, allowing for the generation of more lactate
How does increased lactate from bicarbonate intake affect ghrelin and appetite?
It leads to lower ghrelin levels and reduced appetite
What is the role of lactate in exercise-induced appetite suppression?
Lactate is a mediator
How do dips in blood glucose relate to hunger and energy intake?
They correlate with hunger (r=0.16) and energy intake (r=0.27)
What effect do high glucose concentrations have on ghrelin secretion?
They directly suppress ghrelin secretion in cell cultures
Is blood glucose as relevant as lactate in exercise-induced appetite response?
No
Which type of exercise affects GLP-1?
MICT
How do obese individuals differ from lean individuals in their ghrelin response to fasting?
Obese individuals have significantly lower ghrelin levels when fasted
How does exercise affect ghrelin levels in obese individuals?
Exercise has no effect on their ghrelin
What role does leptin play in appetite regulation?
Many appetite-related hormones may require leptin to function in the regulation of energy intake and expenditure
What happens to leptin sensitivity during chronic positive energy balance?
The body becomes unresponsive to leptin
How do ovarian hormones affect energy intake during the menstrual cycle?
Energy intake is suppressed during ovulation and increased in the luteal phase
How does exercise-induced ghrelin suppression change with high ovarian hormones?
The suppression of ghrelin is blunted
blunted = less strong
How do ghrelin levels differ post-exercise in postmenopausal vs. premenopausal women?
Postmenopausal women have suppressed ghrelin, while premenopausal women in the luteal phase have increased ghrelin
What effects do ovarian hormones have on PYY and GLP-1?
Not much difference
How much lactate is needed to suppress ghrelin?
Above the lactate threshold
What happens to energy expenditure and intake in sedentary individuals?
A decrease in energy expenditure does not decrease energy intake
What happens to energy intake as energy expenditure increases?
Energy intake increases
What is the effect of physical activity on energy intake and weight in non-sedentary individuals
Energy intake can be matched to energy expenditure, resulting in lower weight
What role do IL-6 and glucose play in exercise-induced appetite suppression?
Lack of evidence for a significant role
How does the menstrual phase affect exercise-induced appetite suppression?
Ovarian hormones may blunt the effects of exercise on acylated ghrelin
What kind of exercise is important for decreasing subsequent energy intake?
Exercise intensity
s structured exercise required for maintaining a healthy weight?
No, general activity is sufficient
What characterizes the follicular phase?
Post-menses with decreased ovarian hormones
What characterizes the luteal phase?
Post-ovulation with increased ovarian hormones
