One of the Lancet studies confirmed that obesity and overweight is a growing problem worldwide, even in countries that in the past have had problems with lack of food. The study analyzed the change in body mass index (BMI) from 1,698 studies among 19.2 million adults in 200 countries from 1975 to 2014. The researchers found that during this time period the average BMI increased from 21.7 to 24.2 kg/m2 among men and from 22.1 to 24.4 kg/m2 among women. Average BMIs among men were lowest (21.4 kg/m2) in central Africa and south Asia and highest in 29.2 kg/m2 in Polynesia and Micronesia. Among women, average BMIs were lowest (21.8 kg/m2) in south Asia to and also highest (32.2 kg/m2) in Polynesia and Micronesia. During the same time period, obesity prevalence more than tripled from 3.2% to 10.8% among men and more than doubled (6.4% to 14.9%) among women. By comparison, the prevalence of people are underweight, presumably from lack of enough food, decreased from 13.8% to 8.8% among men and 14.6% to 9.7% among women.
The other Lancet study showed a substantial worldwide increase in a major consequence of obesity, diabetes, since 1980 by analyzing 751 studies that included nearly 4.4 million people. As the study’s senior author Professor Majid Ezzati from Imperial College explained,“obesity is the most important risk factor for type 2 diabetes and our attempts to control rising rates of obesity have so far not proved successful. Identifying people who are at high risk of diabetes should be a particular priority since the onset can be prevented or delayed through lifestyle changes, diet or medication.” The study found that between 1980 and 2014, diabetes prevalence more than doubled from 4.3% to 9.0% among men and climbed by over 50% from 5.0% to 7.9% among women. This corresponded to the number of adults with diabetes worldwide nearly quadrupling from 108 million to 422 million. In 2014, northwestern Europe had the lowest diabetes rates. Polynesia and Micronesia had the highest (affecting nearly a quarter of adults), followed by Melanesia and the Middle East and north Africa. While not all diabetes cases are related to obesity, obesity is a major risk factor for the more common type of diabetes, Type 2 or adult-onset diabetes. And diabetes can have devastating health consequences such as heart problems, kidney disease and stroke. (Of course, obesity can result in many other health problems besides diabetes, such as cancer and heart disease.)