Conclusion: A gradient exists between increasing BMI and direct healthcare costs and indirect costs due to reduced productivity and early premature mortality. Determining precise estimates for the increases is mired by the large presence of heterogeneity among the available cost estimation literature. To improve the availability of quality evidence an international consensus on standardised methods for cost of obesity studies is warranted. Analyses of nationally representative cross-sectional datasets augmented by data from primary care are likely to provide the best data for international comparisons.

An examination of 129 studies conducted the world over that quantify the economic impact of obesity and overweight reveals that obesity and overweight engender significant costs. On the other hand, researchers produce highly variable estimates for a given country. For example, one study concludes that, on average, annual medical expenses incurred for an obese American are $2741 higher than those for an American of normal weight. In contrast, what is more, another study estimates the difference at $620. Similarly, a study commissioned by the House of Commons in the UK estimates that the health care costs associated with obesity in the country account for between 2.3% and 2.6% of all public health spending, while another study estimates at 4.6% the resources that the problem monopolizes.