The present study analyzes body fat distribution, a well-known and important indicator of reproductive capability, in young women between 18 and 28 years of age (mean=23.3 years) suffering from secondary amenorrhea and therefore temporary infertility resulting from self-starvation. Body composition parameters estimated by means of dual energy x-ray absorptiometry and the fat distribution index, indicating body shape, were compared with those of healthy controls. Although members of the infertile, amenorrheic group exhibited dramatically low body weight and total amount of body (...) fat, and therefore a marked negative energy balance in comparison with the healthy controls, the sex-specific fat distribution patterns did not differ between infertile and fertile young women. In contrast, the lower the weight and total fat amount, the more gynoid the fat distribution, even in infertile women. This observation may be interpreted in an evolutionary sense: Our ancestors had to cope with frequent food shortages, even starvation, and therefore lengthy periods of negative energy balance. In addition to pregnancy and lactation, temporary infertility as a result of long-term negative energy balance was not an uncommon phenomenon in female life histories. Nevertheless, after a time of plenty, reproductive function recovered, and therefore the gynoid fat distribution patterns in temporarily infertile young women may be interpreted as signal of reproductive capability, which resumes after a time of surplus. (shrink)

The “reproductive suppression hypothesis” states that the strong desire of adolescent girls in our culture to control their weight may reflect the operation of an adaptive mechanism by which ancestral women controlled the timing of their sexual maturation and hence first reproduction, in response to cues about the probable success of reproduction in the current situation. We develop a model based on this hypothesis and explore its behavior and evolutionary and psychological implications across a range of parameter values. We use (...) the process of model development to identify assumptions implicit in the reproductive suppression hypothesis and variables that need to be measured in order to investigate it more fully. In addition, because costs were probably associated with weight control, an important part of this analysis is the specification of situations in which the benefits of adaptive adjustment of the maturation schedule could have outweighed the costs of achieving that adjustment by slowing adolescent weight gain. (shrink)