The second paper in The Lancet Obesity Series by Dr Y Claire Wang, Mailman School of Public Health, Columbia University in New York, NY, USA, and Professor Klim McPherson, New College, University of Oxford, UK, and their team evaluate obesity trends in the USA and UK including the impact on prevalence of diseases and cost of healthcare.

According to the authors, the amount of chronic and acute health disorders is linked to excess bodyweight burdening society. It affects the individual’s health-related quality of life but also incurs costs to the individual as well as to the society as a whole due to higher cost of health-care and lost productivity.

With currently 99 million obese people in the USA and 15 million in the UK, the two countries represent the highest obesity rates among OECD countries. The trend is set to continue in the coming decades. Numbers vary according to sex and ethnicity.

Approximately a quarter of all men in the USA are obese regardless of ethnicity. Among American women, almost half (46%) are black, compared with a third of Hispanic women and 30% of white women.

In the UK obesity in white men (19%) is marginally higher than in black men (17%) and significantly higher than in Asian men (11%) whilst a third of black UK women are obese, compared with 1 in 5 white women and 1 in 6 Asian women.

The authors used the UK Foresight Group’s methodology* to examine several possible scenarios in their model.

In the first scenario they constructed historic trends by using U.S. data from 1988 to 2008 and UK data from 1993 to 2008 respectively.

A projection of these trends to 2030 revealed that US obesity would rise from 32% (2008) to around 50% (2030) for men, and from 35% to between 45% and 52% for women. In the UK respectively, male obesity prevalence would rise from 26% to between 41-48%, and female obesity from 26% to 35-43%.

The result implies, that by 2030, the USA would have 65 million additional obese adults, raising the total to 164 million, while the UK would have an additional 11 million obese totaling 26 million obese people in the UK. The cost of treating obesity-related diseases in the U.S. would increase by $66 billion per year by 2030, which is an overall increase in health cost of 2.6%. Similarly, the increased cost for the UK would be £2 billion per year, increasing overall health spending by 2%.

Across the two decades health-cost in the USA would increase by 13 to 16% per year with one quarter, i.e. 4% of the 16% due to population ageing. Obesity-related health cost in the UK would increase faster due to its older population as the average age of men in the USA is 36 years compared with 38 years in the UK. Therefore obesity health-cost in the UK would increase by 25% per year, with two fifths (or 10%) within that due to ageing only.

The above scenario would result in 7.8 million additional cases of diabetes in the USA by 2030, together with 6.8 million additional cases of coronary heart disease and stroke, and 539,000 extra cancer cases. For the UK it would result in an extra 668,000 cases of additional diabetes sufferers, 461,000 more coronary heart disease cases, and 130 000 cancer cases.

However, the report emphasizes, that the catastrophic consequences for both countries described above applies if no action is taken, yet a reduction of the population’s BMI by only 1% (representing just 0.9kg for the average 90kg adult) would avoid approximately 179,000 to 202,000 cases of diabetes, 120,000 cases of heart disease and stroke, and 32,000 cancer cases in the UK and respectively in the USA, such action would prevent 2.05 to 2.4 million diabetes cases, 1.4 to 1.7 million cases of heart disease and stroke, and 73, 000 to 127 000 cancer cases.

According to the authors of whether or not the US and UK have turned a corner or leveled out will be unclear, until survey results over the next few years provide additional data points, since population weight changes are slow to manifest.

The controversial issue suggesting that obese people die earlier and are therefore more likely to save expected social and health-care costs compared to those who live longer, has also been discussed in the paper. In a concluding statement the authors comment:

“Without a doubt, health-care expenditure is high for elderly people, but these costs should not be used to justify the cost-savings of dying younger, or to suggest that obesity prevention has no benefit.”

Written by Petra Rattue