Over the past 27 years, Thai women's body shape has changed dramatically. They are now taller, heavier and have bigger waistlines.

According to extensive research, the average height of women under 50 years old has shot up five centimetres while their weight has jumped 5.4 kilograms.

Their waistlines have on average ballooned 3.7 inches and hips and breast circumference have increased by 2 and 2.2 inches respectively.

The research used 3D-scanning technology to measure the size and shape of 13,442 Thais. It was found that the average weight for women is 57kgs, the average height 156.89cms, the average waistline 31.5 inches, average breast circumference 36 inches and average hips 38 inches.

"The fact that women's waistlines have grown almost twice as much as their chests and bottoms means that the shape of the average Thai women has changed," Dr Pansak Siriruchatapong said. Not only have women become bigger, they have also become more cylindrical and have less of the traditional hourglass shape."

Thai men below 50 years of age have an average weight of 68.94kgs, average height of 169.38cms, average chest circumference of 39.1 inches, average waistline of 33.5 inches and average hip circumference of 37.4 inches.

When compared with 1982 data, Thai men are now 7.2cms taller and 11.4kg heavier. Their chest circumference has also expanded by 5.4 inches, their waistline by 4 inches, and hips by 3.4 inches.

Based on the Body Mass Index (BMI), 36.21 per cent of Thai men fall within the "normal" category, 58.43 per cent are overweight, and 5.36 per cent are underweight. For Thai women, 42.26 per cent are "normal", 48.05 per cent are overweight, and 9.69 per cent are underweight.