Regulation of energy balance

What nucleus in the hypothalamus regulates energy balance?

Arcuate nucleus (ARC)

Which neurons in ARC stimulate appetite?

Orexigenic neurons (NPY, AgRP)

Which neurons in ARC suppress appetite?

Anorexigenic neurons (POMC, CART)

What do orexigenic neurons release?

Neuropeptide Y (NPY) and Agouti Related Peptide (AgRP)

What do anorexigenic neurons release?

Proopiomelanocortin (POMC) and Cocaine & Amphetamine Regulated Transcript (CART)

Which signals excite or inhibit ARC neurons?

Circulating neuropeptide hormones

What are long‑term signals to hypothalamus?

Insulin, leptin, adipokines

What are short‑term signals to hypothalamus?

Gut peptides such as CCK and ghrelin

Which neurotransmitters also modulate hypothalamic appetite control?

Serotonin, dopamine, noradrenaline

What three types of responses maintain energy balance?

Behavioral, autonomic, endocrine

Which gut hormone signals satiety?

Cholecystokinin (CCK)

Which gut hormone signals hunger?

Ghrelin

What type of signals are gut hormones?

Short‑term meal‑related signals

What type of signals are insulin and leptin?

Long‑term adipose tissue signals

What was WAT previously considered?

A simple fat depot

What is WAT now recognized as?

A metabolically dynamic endocrine organ

What does WAT secrete?

Biologically active adipokines

What is the state caused by dysregulated adipokine secretion?

Low‑grade inflammatory state

What is the main effect of dysregulated adipokine secretion?

Increased triglyceride hydrolysis and plasma free fatty acids

Which adipose hormone signals fat stores to hypothalamus?

Leptin

What is the main consequence of dysregulated energy balance?

Obesity

Simplistic definition of obesity?

Abnormal or excessive fat accumulation presenting health risk

Clinical definition of obesity?

BMI greater than 30

Nutrition perspective of obesity?

Energy balance dysregulation

Biochemist’s perspective of obesity?

Systemic chronic low‑grade inflammation

Which organ is the “problem organ” in obesity?

White Adipose Tissue (WAT)

What happens to triglycerides in dysregulated adipokine secretion?

Increased hydrolysis

What happens to plasma free fatty acids in dysregulated adipokine secretion?

They increase

What happens in the liver due to increased free fatty acids?

Liposome enlargement, NAFLD, steatohepatitis, cirrhosis

What happens in non‑adipose tissues due to lipid intermediates?

Lipotoxicity, cellular dysfunction, apoptosis

What happens when FFAs combine with inflammatory cytokines?

Impaired insulin sensitivity → insulin resistance

What systemic state does obesity lead to?

Systemic insulin resistance

What happens to glucose production in the liver during obesity?

No suppression of glucose production

What happens to glycogenolysis in obesity?

It increases

What happens to gluconeogenesis in obesity?

It increases

What happens to plasma glucose in obesity?

Hyperglycemia

What happens to glucose uptake in peripheral tissues in obesity?

It decreases

What happens to basal adipose tissue lipolysis in obesity?

It increases

What happens to VLDL production in obesity?

It increases due to decreased glucose uptake

What happens to LPL activity in obesity?

It decreases

What happens to chylomicron lipolysis in obesity?

It decreases

What lipid abnormality results from obesity?

Dyslipidemia

What happens to plasma triglycerides in obesity?

Hypertriglyceridemia

List metabolic consequences of obesity

Insulin resistance, lipotoxicity, dyslipidemia

List cardiovascular consequences of obesity

Coronary Heart Disease, systemic hypertension, congestive heart failure, stroke

List hepatic consequences of obesity

NAFLD, steatohepatitis, cirrhosis

List renal consequence of obesity

Chronic Kidney Disease

Which endocrine consequence arises from obesity?

Type 2 Diabetes

What happens to sympathetic activity in obesity?

It increases

Which organs send signals to hypothalamus for energy balance?

Adipose tissue, gut, other organs

How is energy balance maintained?

Via behavioral, autonomic, and endocrine responses

What does obesity lead to at the systemic level?

Chronic inflammatory state

What metabolic disturbance does obesity cause in carbohydrates?

Hyperglycemia

What metabolic disturbance does obesity cause in lipids?

Dyslipidemia

What chronic disorders develop from obesity?

Diabetes mellitus, chronic renal failure, congestive heart failure

Which hormone from adipose tissue suppresses appetite?

Leptin

Which gut hormone increases appetite before meals?

Ghrelin

Which gut hormone promotes satiety after meals?

Cholecystokinin (CCK)

Which neurotransmitter is linked to reward in feeding?

Dopamine

Which neurotransmitter is linked to mood and satiety?

Serotonin

Which neurotransmitter increases alertness and appetite drive?

Noradrenaline

What is the collective name for disorders caused by obesity?

Chronic metabolic disorders