Waists under one foot nine are considered to be small waists. One foot and nine inches is 64 centimeters. A small waistline describes a woman's waist as thin and has a sense of lines. A small, thin waist.

Waist circumference: the horizontal circumference passing through the navel center, or the circumference of the line connecting the lowest point of the rib with the midpoint of the top edge of the iliac crest, measured with a soft ruler, and measured before inhaling at the end of expiration.

The normal range of waist circumference is:

Male: Height (cm) ÷2- 10 (cm)

Female: Height (cm) ÷2- 13 (cm)

Results 5% is the normal range.

Waist circumference:

Height waist circumference index = (waist circumference/height) × 100, waist-hip ratio = waist circumference/hip circumference. These two indexes are higher in men than in women, and the difference is significant. Height and hip circumference index = (hip circumference/height) × 100, height and thigh circumference index = (thigh circumference/height) × 100, and thigh length index = (thigh circumference/thigh length) × 100. These three indexes are higher for women than for men, with significant differences. In other words, men of the same height have thicker waists, while women have wider hips and thicker thighs. This is related to the gender difference in body fat distribution. Estrogen inhibits fat accumulation in the upper abdomen and increases fat accumulation in the buttocks and thighs.

Pear-shaped and hourglass-shaped women with thin hips and thick thighs are healthier and live longer than rectangular, apple-shaped and inverted triangular women with thin hips and thin thighs. Pear-shaped and hourglass-shaped women and their offspring have higher cognitive ability, and the fat stored in buttocks and thighs contains omega-3 polyunsaturated fatty acids (DHA) which is indispensable for fetal brain development.

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