If rates of obesity continue to follow the current trends, half of the United States population will suffer from obesity within the next two decades. With projections that the number of obese people in America will climb from 99 million in 2008 to 164 million by 2030, obesity-related diseases and health care costs are expected to soar. The disturbing information come from a new report recently published in the journal The Lancet.

According to Claire Wang, assistant professor of health policy and management at Columbia University’s Mailman School of Public Health and lead author of the study “At the rate we’re looking at right now, it’s a dire prediction. Something has to be done.”

The report, second in a series of articles on obesity published in the journal, projects that the number of obese people in the United Kingdom will rise to almost double from 15 million to 26 million in the next 19 years. Rates of obesity in both the U.S. and U.K. have already become the highest among all 34 member nations of the Organization for Economic Development and Cooperation (OECD).

Based on the analysis of U.S. data from 1988 to 2008, and U.K. data from 1993 to 2008, the report states that the obesity rate is expected to increase from 32 percent to approximately 50 percent among American men, and from 35 percent to somewhere in the range of 45 percent to 52 percent among U.S. women. Similarly, the rates of obesity in the U.K. will climb from 26 percent to between 41 percent and 48 percent among men, and from 26 percent to between 35 percent and 43 percent among women.

Wang pointed out, “It’s not only a problem of well-being - it’s a financial burden.” She then added, “It’s both a public health issue and a health services issue for the states.”

The cost of treating obesity-related diseases, including diabetes, heart disease and stroke, are projected to increase $66 billion annually by 2030 in the U.S. alone, accounting for a 2.6 percent hike in overall health spending. More specifically, spending on obesity-related medical problems is expected to jump by 13 to 16 percent each year if obesity rate increases continue on the current track, with only about 4 percent of the increase being due to an aging population. The rise in obesity is expected to lead to 7.8 million additional cases of diabetes, and 6.8 million more cases of coronary heart disease and stroke, as well as 539,000 added cancer cases by 2030.

For the U.K., overall healthcare costs will reach $3.2 billion per year, an increase of two percent, with costs for obesity-related conditions soaring 25 percent annually over the next two decades. About 10 percent of the increase is attributed to population aging. Additional medical conditions caused by the rise in obesity rates will result in 668,000 more cases of diabetes, 461,000 additional cases of coronary heart disease, and 130,000 extra cases of cancer.

The study also found that rates of obesity differ by gender and ethnicity, with about 25 percent of all American men being obese in 2008, compared to 30 percent of white women, 33 percent of Hispanic women, and 46 percent of black women. Among the population in the U.K., 11 percent of Asian men, 17 percent of black men, and 19 percent of white men are obese, as are 16 percent of Asian women, 20 percent of white women, and 33 percent of black women.