Everyone knows The Truth about obesity. A large and growing number of us have expanded waist lines. Consequently, our irrational and poor choices are leading us to illness and early death. Given this dire public health scenario, only government intervention can save us from ourselves.

An empirical evaluation of this truth reveals a very different story, however.

Measurements of overweight and obesity among the Canadian population from Statistics Canada suggest that the contemporary Canadian situation largely lacks a negative or disconcerting trend. Among Canadian adults, there has been no statistically significant change in the rate of overweight (Body Mass Index between 25 and 30) among the population between 2003 and 2012. With respect to obesity (Body Mass Index greater than 30), the rate of obesity among Canadian adult males appears to have stabilized or perhaps even begun to decrease, with there now being no difference between the rate in 2012 and that in 2007. For adult females, however, there has been a steady increase in the prevalence of obesity since 2003. Among Canadian youth (aged 12 to 17), the rates of overweight and obesity between 2005 and 2012 are largely unchanged (2003 data were not available). This remains true even when data are separated for males and females.

Overall, while the prevalence of overweight and obesity may remain relatively high historically, the state of Canadians’ waistlines is only really continuing to expand among adult females. On the other hand, the shares of Canadian adult males and Canadian youth carrying excess weight appear to have stabilized and may be turning a corner among obese adult males.

The health consequences of excess weight might also be overstated in the popular debate. A number of studies of the relationship between overweight, obesity, and early mortality have suggested that the risks associated with obesity lie at the higher end of the scale, above a BMI of 35 (known as Class II or Class III obese). They also suggest those who are classified as overweight, with a BMI between 25 and 30, may have lower rates of premature mortality than those who are “normal weight,” while those who would fall into the Class 1 obese range with a BMI of 30 to 35 face similar risks to those in the normal weight range.

This suggests that the health-based justification for obesity interventions may only exist among a small section of the population with BMIs over 35; a much smaller group of the population than is commonly claimed to be at risk from their lifestyle behaviours/choices.

While much of the focus on the obesity problem relates to the health consequences of carrying too much excess weight, there is also the important concern about the costs obesity imposes on the economy. Indeed, many advocates of government intervention justify the need for intervention by pointing to the increased burden on Canada’s tax-financed health system. A closer examination of the consequences of excess weight finds, however, that the majority of the costs of obesity are borne directly by the individual—in terms of lower income, reduced employment opportunities, reduced enjoyment of life, greater illness, and a potentially shorter lifespan, all of which may provide incentives for weight loss. It also finds that the justification for intervention on the basis of resolving the insurance externality—created by the costs obese individuals impose on others through the tax-funded health care system—is weakened by the possibility that obese individuals may in fact not be a net burden to taxpayers over their lifetimes, and by the possibility that there may be a positive innovation externality.

There is also little solid evidence that commonly proposed government policy interventions could systematically reduce the prevalence of excess weight and obesity. To the contrary, even if concerns about poor consumer decision making as a result of limited information and hyperbolic discounting are correct, commonly recommended interventions (e.g., fat taxes or junk food taxes, menu labeling requirements, reduced availability of/access to particular foods, simplified or directive food labels, graphic warning labels, vending machine bans, zoning restrictions, and advertising restrictions) are likely unable to reduce the prevalence of obesity. Private solutions to the problem of excess weight may be more effective in helping individuals reduce excess weight.

While government interventions may not be effective in reducing obesity prevalence, they would impose costs indiscriminately (and potentially regressively) on both non-obese and obese Canadians, not to mention inappropriately vilify particular foods and food manufacturers. Increased costs for individuals and families might come from reduced options/choices, increased travel times, increased costs from taxation, increased costs of goods and services as a result of regulation, or taxpayer funding of programs and of the increased bureaucracy that may be required. Interventions may also create barriers to entry for smaller businesses or artificial constraints on growth, and generate higher business costs from regulation. Interventions may also result in a transfer of funds from one group of legal businesses to another simply because one provides a product that is disliked by interventionists.

In total, a review of the facts about the prevalence of obesity, the risks associated with obesity, and the efficacy of commonly proposed policy interventions suggests a very different truth about obesity. While there still may be too many expanded Canadian waist lines, the number appears to have stabilized and may even be turning a corner. Further, health concerns associated with obesity may impact fewer of those with excess weight than is sometimes suggested by advocates of government intervention. Finally, commonly proposed government interventions would not be likely to change behaviours in ways that systematically lead to a lower prevalence of obesity.