Sattva denotes having the natural quality of purity and goodness. For something (such as food) to be considered sattvic, it should not increase evil or disease, and must be pure and natural.
Sattva can also be considered an emotional or mental state wherein the mind is at peace. Sattvic individuals often strive to deepen, strengthen and mature the soul. Many people cultivate sattva through practicing a sattvic diet, which includes foods that are considered most pure and life-giving to the body.