Two hormonal regulators which have been studied are leptin and ghrelin,
whose effects on energy balance are in a large part mediated by the hypothalamus.87 Leptin, a peptide hormone secreted by adipose tissue, acts to reduce
appetite.87 Circulating levels are proportional to adiposity and so decline during weight -
loss, thus increasing
appetite, however this reduction is believed to be disproportionately greater than the change in fat - mass.82 As expected, IER (60 - 85 % ER on restricted days) weight -
loss interventions have all noted a decline in leptin levels 39, 41, 46 - 49, 52, comparable with energy - matched CER protocols after three months 48 and six months.41