A study, published in the journal The Lancet, says Tonga is the fattest country in the world.

Listed below are the top 10 countries with the highest rates of obesity and overweight in adults older than age 20.

Scientists typically measure obesity based on body mass index, or BMI, a measure of body fat based on height and weight.

A BMI from 19 to 25 is considered healthy, 25 to 30 is overweight, and over 30 is obese.

Countries with the highest rates of obesity and overweight in adults:

Tonga

Samoa

Kiribati

Kuwait

Qatar

Marshall Islands

Egypt

Micronesia

Libya

Jordan