Nearly two billion adults worldwide are overweight, more than 600 million of whom are obese. In addition to increasing risk of conditions such as diabetes and heart disease, obesity is also a known risk factor for cognitive disorders including Alzheimer’s disease. Obesity leads to cognitive impairment by activating microglial cells, which consume otherwise functional synapses in the hippocampus, according to a study of male mice published in JNeurosci.
— source sfn.org