The laws of thermodynamics require that overall energy balance should be constantly maintained in living organisms during periods of stable weight. Weight gain results from an imbalance between energy intake and expenditure. Correlation of energy intake and expenditure with energy stores is a complex process, controlled in the hypothalamus and involving numerous amine and peptide neurotransmitters and neuromodulators.
The hypothalamus senses adipose tissue mass (energy stores) by reception of leptin, a circulating signal generated in adipose cells. Obesity can result from an altered set point of energy stores, from unregulated caloric intake, decreased energy use or resistance to the action of leptin.1
Leptin and ghrelin are two hormones that have been recognised to have a major influence on energy balance. Leptin is a mediator of long-term regulation of energy balance, suppressing food intake and…
