Insulin & Metabolism
What hormone acts as a major brake on adipose lipolysis after eating?
Insulin.
What does GLP-1 generally do to appetite and satiety?
Decreases appetite and increases satiety.
“Carbohydrates are bad and should be avoided for weight loss.” Myth or science?
Myth. Carbohydrates are an important fuel; amount, quality, context and total dietary pattern matter.
Fat tissue is just passive storage for extra calories. True or false?
False. Adipose tissue is metabolically and hormonally active.
After a mixed high-carb/high-fat meal, which fuel's oxidation generally increases rapidly as carbohydrate availability rises?
Carbohydrate.
What additional receptor does tirzepatide activate that semaglutide does not?
GIP receptor.
Being in fat-burning mode automatically means you're losing body fat.” Myth or science?
Myth. Increased fat oxidation at a particular moment does not necessarily mean net body-fat loss over time.
Name two signaling substances released by adipose tissue.
Examples include leptin, adiponectin, IL-6 and other adipokines/cytokines.
What happens to adipose lipolysis as insulin falls between meals or during fasting?
Lipolysis generally increases, making stored fatty acids more available.
Name three major sites/systems affected by GLP-1–based therapy.
Brain/appetite centers, pancreas/glucose regulation and GI tract/gastric emptying.
“Separating all carbohydrates and fats guarantees greater fat loss.” Myth or science?
Myth. Fuel partitioning changes after meals, but sustained body-fat loss depends on longer-term energy balance and other factors.
As adipocytes enlarge and become dysfunctional, what process can contribute to insulin resistance?
Chronic low-grade inflammation/inflammatory signaling.
Sarah hasn't eaten since dinner. Her insulin is lower the next morning. Does that prove she's losing body fat?
No. Fat mobilization/oxidation may be higher, but net body-fat change depends on energy balance over time.
A patient says, “If GLP-1 reduces my hunger, I don't need to worry about nutrition or exercise.” How would you respond?
Medication is one tool. Adequate nutrition/protein, resistance training/movement, sleep/recovery and ongoing support remain important.
“Everyone who starts a GLP-1/GIP medication must stay on an injection for life.”
Myth as an absolute statement. Obesity is often chronic and weight regain after withdrawal is common, but long-term treatment decisions are individualized.
Why can losing weight make maintaining that loss biologically difficult?
Compensatory responses can include increased hunger, altered satiety signaling and reduced energy expenditure/adaptive thermogenesis.