While metformin may reduce food intake and body weight, researchers have not been able to fully understand the drug's anorexigenic effects.
Under normal physiological conditions, Prof. Zheng Zhao and his team from the Key Laboratory of Brain Functional Genomics, Ministry of Education, China observed the changes in food intake after administration of metformin. They found that the central administration of metformin significantly reduced food intake and body weight gain, and a reduction of neuropeptide Y expression and induction of AMP-activated protein kinase phosphorylation in the hypothalamus were also observed, which could be reversed by compound C, a commonly-used antagonist of AMP-activated protein kinase. Furthermore, metformin also improved lipid metabolism by reducing plasma low-density lipoprotein. These findings were published in the Neural Regeneration Research (Vol. 8, No. 25, 2013).