In 2012, Ricky Naputi, a Pacific Islander from Guam and one of the world’s heaviest men, died from obesity-related complications. Weighing in at over 900 pounds, he was confined to his bed and couldn’t even stand up by himself. Unfortunately, Naputi's case isn't the only one; Pacific Islanders are some of the most obese people in the world. Now, a new study from Oxford University may have determined why residents of Nauru and the Cook Islands — both Pacific Islands — have such high rates of obesity. According to the study, we can blame that on the islands' colonization, which led to significant lifestyle changes among residents, especially when it came to their diets.

The tiny island of Nauru is the smallest country in the South Pacific. It was colonized by both the British and Germans at different points in time until WWI, when it entered a UN-mandated trusteeship between the UK, Australia, and New Zealand. In 1968, it became an independent country. The Cook Islands history follows a similar path. It became a British protectorate in 1888, and was annexed by New Zealand in 1901. It gained political independence in 1965.

In order to understand why the average body mass index (BMI) in these islands jumped between 1980 and 2008, making it four times higher than the global average, Oxford anthropologists Dr. Amy McLennan and Professor Stanley Ulijaszek examined scores of existing and archived academic literature about the islands. They also interviewed indigenous locals and lived on the islands for a short period of time so they could get a first-hand account of lifestyle.

Their research paper, published in the journal Public Health Nutrition, provides historical evidence that colonists changed indigenous lifestyles through the introduction of "proper" food-eating habits — part of an attempt to "civilize" the islanders. They essentially changed traditional food growing and consumption habits. It was also around this time that traditional diets of fish, vegetables, and coconuts were replaced with imported foods. Practices such as eating raw fish eventually turned into eating fried fish.

The transformation was further completed through land grabs for mining and cultivation of cash crops, which rendered the land previously used for food gathering infertile or inaccessible. The study also suggests that excessive shipping in the waters surrounding the island led to the destruction of coral reefs — a rich source of food. Because the islands are small, populations are tightly knit, meaning it didn't take long for unhealthier food habits to spread.

This loss of traditional cooking methods has continued to the present day, with the islands importing huge amounts of canned food from nearby countries like New Zealand and the U.S. At the same time, colonists had once encouraged families to grow large to combat infectious disease epidemics, which has led to larger populations today, and more obesity.

"Under colonial rule, much changed in how food was sourced, grown, and prepared, and the social change was swift," McLennan said in a statement. "What happened to the land also changed as colonial agriculture and mining industries expanded. There was an increase in family size meaning food was increasingly imported."

The silver lining, she said, is that this damage can be reversed if islanders adopt healthier lifestyles. That effort must be undertaken by entire communities though, not just those who are obese. A good way to do that is to tap into the “naturally occurring social networks on the islands” in order to spread a new and effective method to tackle obesity.

Source: McLennan A, Ulijaszek S. Obesity emergence in the Pacific islands: why understanding colonial history and social change is important. Public Health Nutrition. 2014.