Gynoid fat is the body fat that forms around the lower body, specifically the hips, thighs and buttocks.

Gynoid fat in females is used to provide nourishment for offspring, and is often referred to as 'reproductive fat'. This is because it contains long-chain polyunsaturated fatty acids (PUFAs), which are important in the development of fetuses.

Gynoid fat is mainly composed of long-chain polyunsaturated fatty acids. It is proposed that babies which are breast-fed are more likely to have increased cognitive capabilities due to these fatty acids being present in the breast milk, as they have been suggested to aid early brain development in fetuses and newborns. The most notable fatty acids found in human breast milk are docosahexaenoic acid and arachidonic acid, which have been shown to play crucial roles in the healthy formation and functions of neurons.

Gynoid fat contributes toward the female body shape that girls begin to develop at puberty; it is stored in the hips, thighs and bottom. This process is modulated by estrogen, the female sex hormone, causing the female form to store higher levels of fat than the male form, which is affected primarily by testosterone.

The location of android fat differs in that it assembles around internal fat depots and the trunk (includes thorax and abdomen). Android fat has more of a survival role and is utilised by the body as an energy source when energy supplies are low, in contrast to the reproductive functions of gynoid fat.

Gynoid fat is regarded as a physically attractive feature, serving as an indication towards a woman's reproductive potential.

It is primarily a store of energy to be expended in the nurturing of offspring, both to provide adequate energy resources during pregnancy and for the infant during the stage in which they are breastfeeding. When there are insufficient energy resources in the environment or health issues which require energy to combat, a woman's storage of gynoid fat is likely to be reduced. Therefore, a female with high levels of gynoid fat would be signalling to males that they are in an optimal state for reproduction and nurturing of offspring. This can be seen in the fact that a female's waist–hip ratio is at its optimal minimum during times of peak fertility—late adolescence and early adulthood, before increasing later in life.

As a female's capacity for reproduction comes to an end, the fat distribution within the female body begins a transition from the gynoid type to more of an android type distribution. This is evidenced by the percentages of android fat being far higher in post-menopausal than pre-menopausal women.