Mice consuming a high-fat diet generate new neurons in a part of the brain that controls feeding and metabolism. These cells may, in turn, promote the accumulation of fat.

Seth Blackshaw at Johns Hopkins University in Baltimore, Maryland, and his colleagues found a region of brain-cell production in the hypothalamus — which regulates eating and energy use — in young adult mice. Animals fed a high-fat diet had four times the rate of neuronal production in this region, called the median eminence, than those on a normal diet.

When this brain-cell generation was blocked, mice on the fatty diet gained less weight and exhibited a speedier metabolism than animals that ate the same diet and continued to produce new neurons.

Nature Neurosci. http://dx.doi.org/10.1038/nn.3079 (2012)