World’s Obese Population Hits 640 Million, According to a Study

In Spain one in every four adults is currently obese, according to the largest ever study on obesity conducted to date.


Researchers from CREAL, an ISGlobal allied centre, have participated in the largest study of obesity ever done in the world. It has estimated at more than 640 million people the total world population are suffering from obesity, the highest figure recorded in history. In this study more than 700 researchers were involved across the globe, who have collected and incorporated measurements of weight and height from nearly 20 million adults from 186 countries.

The study, led by scientists from Imperial College London and recently published in The Lancet, calculated and compared BMI among adult men and women from 1975 to 2014. The data revealed that in four decades global obesity among men has tripled - from 3.2% in 1975 to 10.8%. Obesity among women meanwhile has more than doubled, from 6.4 % in 1975 to 14.9% in 2014. This translates as 266 million obese men and 375 million obese women in the world in 2014. It also means the world’s population has become heavier by around 1.5kg in each subsequent decade since 1975.

In addition, 2.3% of the world’s men, and 5% of the world’s women are now classed as severely obese, which is defined as having a BMI of over 35 kg/m2. This places an individual at significantly increased risk of conditions such as diabetes, heart disease and cancer.

The team predicted if these global trends continue, by 2025 18% of the world’s men and 21% of women will be obese. Furthermore, the probability of reaching the World Health Organization global obesity target (which aims for no rise in obesity above 2010 levels by 2025) will be close to zero.

Analysis of the findings showed that China and the USA are the countries with the highest number of obese people in the world. However the USA still has the highest number of severely obese men and women in the world.

“The findings showed that average BMI was higher in English-speaking high-income countries than in non-English speaking high-income countries, with American men and women having the highest BMI and Japanese men and women having the lowest BMI of any high-income country”, explained Dr. Martine Vrijheid, researcher at CREAL who participated in the study.

The situation in Spain

According with the data of the study, in Spain one in every four adults, which translates into nearly 10 million adults, is currently obese. In 2014, Spain globally ranked at the 35th highest BMI for men and 106th highest for women.

Morbid obesity and underweight

The study also showed that morbid obesity, where a person’s weight interferes with basic physical functions such as breathing and walking, now affects around 1 % of men in the world, and 2% of women. In total, 55 million adults are morbidly obese.

The team also examined the number of people who are underweight in different countries. The results revealed levels have decreased from 14% to 9% in men, and 15% to 10% in women. The percentage of underweight individuals was nonetheless still quite high in countries such as India and Bangladesh, where nearly a quarter of adults are underweight.

“The study findings show overall that while we are winning the battle of underweight, we are losing the battle against obesity. Given that this condition is hard to treat, the ongoing efforts to prevent obesity, starting very early in life, should be broadened and intensified in the next years to come”, concluded Dr. Dania Valvi researcher at CREAL and Harvard T.H. Chan School of Public Health who also participated in this study.


Trends in adult body-mass index in 200 countries from 1975 to 2014: a pooled analysis of 1698 population-based measurement studies with 19·2 million participants. The Lancet , Volume 387 , Issue 10026 , 1377 – 1396.

More information:

Interactive maps, created by the Imperial College London team, showing obesity across the world are available at