The Waist-to-Hip Ratio (WHR) is a measurement used to assess how body fat is distributed across the frame. This ratio is calculated by dividing the circumference of the waist by the circumference of the hips, resulting in a single number that reflects body shape. The widely referenced 0.7 WHR has garnered significant attention as a marker for health outcomes and in human evolutionary and aesthetic studies.
Calculating the Waist-to-Hip Ratio
Determining your own WHR requires two precise measurements using a flexible tape measure. The first measurement is the waist circumference, taken at the narrowest point of the torso, typically just above the navel. Ensure the tape is snug against the skin without compressing it, and the measurement should be taken after exhaling naturally.
The second measurement is the hip circumference, taken around the widest part of the buttocks and hips. The final ratio is calculated by dividing the waist circumference by the hip circumference. For example, a 30-inch waist divided by 40-inch hips yields a WHR of 0.75.
The Health Significance of Body Shape
Body shape, as quantified by the WHR, is considered a superior predictor of certain health risks compared to Body Mass Index (BMI) alone. This is because the ratio differentiates between fat stored beneath the skin and the more dangerous visceral fat. Visceral fat accumulates deep within the abdominal cavity, surrounding internal organs, and is metabolically active.
A WHR significantly above the 0.7 ratio often indicates a higher concentration of this visceral fat, resulting in an “apple” body shape. This abdominal fat is directly linked to an increased risk for several chronic conditions, including metabolic syndrome, type 2 diabetes, and cardiovascular disease. The World Health Organization identifies cut-off points where health risks increase substantially, generally above a WHR of 0.85 for women and 0.90 for men.
Studies suggest that the WHR has a stronger and more consistent association with all-cause mortality than BMI, particularly as people age. The harmful substances released by visceral fat can trigger systemic inflammation and contribute to high blood pressure and elevated cholesterol levels.
Aesthetic and Evolutionary Drivers
The 0.7 WHR has been the subject of extensive research into human perception and mate selection. Psychologist Devendra Singh’s work highlighted this specific ratio in women as being cross-culturally and historically preferred in aesthetic judgments. This preference is theorized to stem from an evolutionary mechanism, where the ratio unconsciously signals optimal reproductive health and fertility.
A lower WHR in women is strongly associated with higher levels of estrogen, which promotes the storage of fat in the hips and thighs rather than the abdomen. This fat distribution is linked to regular ovulatory cycles and a greater likelihood of successful pregnancy, making it a reliable indicator of biological fitness. Conversely, women with higher WHRs tend to have more irregular menstrual cycles and lower pregnancy rates.
The ratio signals reproductive status because conditions like menopause and certain hormonal disorders, such as Polycystic Ovary Syndrome, tend to increase the WHR. For men, the preferred ratio is higher, typically falling closer to 0.9, where a more columnar shape is generally considered attractive. This difference underscores how the ratio functions as a sex-specific indicator of reproductive capability.