According to the Bhagavadgita, the gunas are three in number, sattva, rajas and tamas. They exist in all, including humans, in various degrees of concentration and combination. They also exist in all objects and natural products. Hence, even the food which we eat is important if we want to cultivate good behavior. Depending upon their relative strengths and ratios, the gunas determine the nature of things, beings, their actions, behavior, attitude and attachments and their involvement with the objective world in which they live. The primary purpose of the gunas in the living beings is to create bondage, through desires for sense objects, which lead to various attachments with them and which in turn keep them bound to the world and under the perpetual control of Prakriti.