Silencing Scer\GAL4Mip.PM neurons significantly increases body weight (BW) (by 20-30% compared to controls) and leads to enlarged abdomens (with denser layers of fat body cells) in male and female flies. BW increase is apparent 1 day after eclosion, peaks at 5-10 days and then stabilizes. There is no difference in body or wing length shortly after eclosion, compared to controls. Temporal silencing in the adult (using Scer\GAL80ts.αTub84B) is sufficient to increase BW. Flies with silenced neurons eat twice as much as controls and survive twice longer than controls without food; the BW phenotype is only evident in ad libitum but not restricted feeding conditions. Activating Scer\GAL4Mip.PM neurons show significant BW loss and leaner abdomens with less fat tissue in males and females (around 30% compared to controls). Before Scer\GAL4Mip.PM neuron activation, flies eat the same amount as controls; upon activation, flies eat 70% less food than controls; after ending activation, flies show a feeding rebound (eating 70% more than controls). Silencing Scer\GAL4Mip.PM neurons in the presence of suppresses increases in BW phenotypes. Activating Scer\GAL4Mip.PM neurons leads to decreased BW, but no change in BW is seen with the additional presence of Mip1/Mip1; presence of Df(1)Exel6234 in flies with activated Scer\GAL4Mip.PM neurons still show decreases in BW. Silencing Scer\GAL4Mip.PM neurons significantly increases attraction to food odors (whereas activating neurons significantly decreases attraction) compared to controls. Satiated flies with silenced Scer\GAL4Mip.PM neurons show significant increases in proboscis extension response (PER, to sucrose solution) compared to controls, as if they were starved; this effect is not present if the flies are starved for 18hrs. Activating Scer\GAL4Mip.PM neurons leads to significant decreases in PER (after 18hr starvation) compared to controls. Flies with silenced Scer\GAL4Mip.PM neurons have significantly more sensitive ab3A olfactory receptor neuron responses to ethyl butyrate than controls, and flies are hyperphagic on sweet (but not non-sweet) substances. Scer\GAL80ChAT.7.4P suppresses increases in body weight seen in male and female flies with silenced Scer\GAL4Mip.PM neurons.