The anatomical feature commonly known as the Adonis belt, also referred to as the iliac furrow, is a V-shaped depression in the lower abdominal area. This feature is not a muscle developed through exercise, but a visible display of underlying anatomical structures. Women possess the exact same anatomy as men that forms this feature. The difference between the sexes lies in the typical body composition that determines whether this structure is visible.
The Anatomy of the Iliac Furrow
The iliac furrow is a shallow groove that runs down the lower abdomen from the hip bone toward the pubic area. This depression is formed by the inguinal ligament, a band of connective tissue. The ligament runs between the anterior superior iliac spine (a bony point on the hip) and the pubic tubercle, and is the thickened lower edge of the external oblique muscle’s tendon.
The visibility of the Adonis belt is determined by the absence of subcutaneous fat that typically covers the area. When the layer of fat just beneath the skin becomes thin enough, the tension of the inguinal ligament creates the visible indentation. The feature is present in all human bodies, but is obscured by body fat until a very low level is achieved. Since the external oblique muscles meet the hips near this ligament, the appearance of the belt is often associated with a highly toned core.
Factors Affecting Visibility in Women
The primary factor governing the visibility of the iliac furrow is body composition, specifically the percentage of body fat. For the feature to become noticeable, an individual must reduce their body fat levels until the subcutaneous fat layer in the lower abdomen is minimal. This requirement presents a greater biological challenge for women due to differences in essential fat and hormonal regulation.
Women require a significantly higher amount of essential body fat—the minimum necessary for basic physiological health—compared to men. For women, this essential fat level is generally 10% to 13% of total body weight, while men require only 2% to 5%. This difference is directly related to reproductive health and hormonal function.
Furthermore, the hormone estrogen dictates a gynoid fat distribution pattern in women, favoring storage in the hips, thighs, and lower abdomen. Since this is the exact area where the iliac furrow is located, women naturally carry more fat over the structure that forms the belt. Male fat storage tends to be more android, or central, leaving the lower abdominal area relatively leaner at comparable body fat percentages.
Female athletes, who are highly conditioned, maintain body fat percentages in the range of 14% to 20%. For the Adonis belt to become defined, a woman would need to reach the very low end of this athletic range, or even slightly below it. This level of leanness is difficult to sustain and approaches the essential fat threshold, illustrating why the feature is far less common in women than in men.
Health and Fitness Considerations for Low Body Fat
Achieving the extremely low body fat percentage needed for the iliac furrow often requires a restrictive diet and a highly regimented exercise routine. Maintaining body fat at or near the essential level carries significant health risks for women. When the body perceives energy deficiency, it begins to shut down non-survival functions, resulting in hormonal disruption.
A common consequence of insufficient energy availability is functional hypothalamic amenorrhea, the loss of the menstrual cycle. This cessation of menstruation signals low estrogen levels, which detrimentally affect bone health. Low estrogen suppresses bone production, leading to reduced bone mineral density, or osteopenia, and increasing the risk of stress fractures and osteoporosis.
The bone loss due to amenorrhea can be severe and sometimes irreversible, especially if it happens during adolescence when peak bone mass is being established. Other health issues associated with maintaining an unsustainably low body fat level include impaired immune function, chronic fatigue, and cardiovascular dysfunction. For the average woman, pursuing the visible Adonis belt may compromise long-term health and reproductive function.