In virtually all organisms, life expectancy is profoundly affected by caloric intake. For example, dietary restriction (DR; a feeding regimen of fewer calories compared to the ad libitum level without causing malnutrition) has been shown to lengthen, whereas hypercaloric (HC) diet feeding to shorten, lifespan. Recent findings in invertebrates indicate that specialized groups of cells (e.g.: metabolic-sensing neurons) detect changes in caloric intake and convey energy-status-variation signals to other cells in the body to regulate lifespan. In mammals, whether metabolic-sensing neurons govern aging in a cell-non-autonomous fashion is unknown. Yet, this is a captivating and testable hypothesis.