Pg 36-66 Flashcards
(21 cards)
What evolutionary theory explains our vulnerability to overeating in modern times?
Humans evolved mechanisms to protect against energy deficits, but not against food excess, making us prone to overeating in food-abundant environments.
How does gastrointestinal distension contribute to satiety?
It activates stomach mechanoreceptors, sending signals to the brain that promote a feeling of fullness.
How does the liver communicate nutrient presence to the brain?
Through the vagus nerve, signaling the presence of fatty acids, glucose, and amino acids.
Which part of the brain plays a key role in appetite regulation?
The hypothalamus, especially the arcuate nucleus, which contains neurons that regulate food intake.
Name two hormones that stimulate and suppress appetite.
Ghrelin stimulates appetite; Leptin and CCK suppress it.
What is the function of Cholecystokinin (CCK)?
Stimulates bile and pancreatic enzyme release, delays gastric emptying, and promotes satiety, especially after fat- and protein-rich meals.
What are insulin’s key metabolic roles?
Facilitates glucose storage as glycogen, promotes fat storage, inhibits gluconeogenesis, and reduces hunger via the hypothalamus.
What is a major hormonal consequence of chronic overnutrition and inactivity?
Hyperinsulinemia, leading to inhibited lipolysis and eventual insulin resistance.
How does visceral fat contribute to chronic disease?
It releases inflammatory cytokines (e.g., TNF-α, IL-6), increases free fatty acids, and promotes systemic inflammation.
What liver condition is linked with insulin resistance?
Non-Alcoholic Fatty Liver Disease (NAFLD), due to disrupted glucose metabolism and storage.
How is fructose metabolized differently from glucose?
It’s converted to fat in the liver when glycogen stores are full, contributing to NAFLD and metabolic issues.
What hormone increases with food deprivation and may explain post-diet weight regain?
Ghrelin, which stimulates hunger and increases after weight loss.
What causes leptin resistance despite high leptin levels in obesity?
Inflammation and altered cellular signaling weaken leptin’s appetite-suppressing effect.
List 3 ways to increase leptin sensitivity.
Go gluten-free, reduce fructose intake, and support gut flora with prebiotics.
How is gut microbiota linked with obesity?
Obese individuals have a higher Firmicutes/Bacteroidetes ratio; gut flora can influence weight gain.
What are SCFAs, and how do they affect appetite?
Short-chain fatty acids from gut bacteria increase satiety hormones and help maintain gut barrier function.
What are the benefits of pre- and probiotics for metabolic health?
Improve insulin sensitivity, suppress ghrelin, and enhance satiety.
What’s the difference between appetite and hunger?
Appetite is a psychological desire for food; hunger is a physiological need for food.
Why are high-fat/sugar foods so appealing from an evolutionary standpoint?
They activate the brain’s dopamine reward system, which evolved to favor calorie-dense foods.
What cultural factors can influence food intake?
Traditions, celebrations, social meals, and attitudes towards leftovers.
What sensory and psychological factors affect food intake?
Smell, taste, food addiction, packaging, advertising, and eating environment.
