Obesity is characterised by increased adiposity, high leptin levels, and leptin resistance. Plasma leptin concentration is positively correlated with fat mass. Fasting decreases body fat and consequently decreases leptin levels. Obesity is a risk factor for type 2 diabetes mellitus (T2DM). T2DM is characterised by increased fasting glycaemia and impaired glucose tolerance. Insulin resistance is a common feature between obesity and T2DM. Leptin and insulin act on the same neuronal population within the arcuate nucleus of the hypothalamus (ARH). Our previous work demonstrated that Diet-induced obese (DIO) mice show no response to insulin, but still demonstrate leptin signalling in the ARH. Pharmacological blockade of leptin signalling in the CNS restores insulin signalling in DIO mice, thereby improving glucose homeostasis. However, utilising fasting to decrease leptin level and exert a physiological rescue of insulin signalling has not been investigated yet. We hypothesised that decreasing endogenous leptin level using a 48-hour fasting could reduce leptin response in the ARH and promote the restoration of insulin signalling and glucose tolerance in DIO mice. Mice are fed with chow diet or high-fat diet for 20 weeks, followed by a baseline glucose tolerance test (GTT). After a two-week recovery, the DIO mice will then be divided into two groups: ‘DIO fed’ mice, fed ad libitum, or ‘DIO F48’ mice, fasted for 48 hours prior to the final GTT undergone by all mice. Following the final GTT, mice received either saline or insulin for histological signalling studies. Brain slices will be immuno-stained for phosphorylated signal transducer and activator of transcription-3 (pSTAT3) and phosphorylated protein kinase-B (pAkt). pSTAT3/pAkt co-localisation is used a marker of leptin receptor activation, while pAkt-alone a marker of insulin action. This will determine whether reducing leptin level will decrease endogenous leptin signalling and possibly restore insulin action in the ARH of DIO mice.