Imagine a country where the government regularly checks the waistlines of citizens over age 40. Anyone deemed too fat would be required to undergo diet counseling. Those who fail to lose sufficient weight could face further "reeducation" and their communities subject to stiff fines.

Is this some nightmarish dystopia?

No, this is contemporary Japan.

The Japanese government argues that it must regulate citizens' lifestyles because it is paying their health costs. This highlights one of the greatly underappreciated dangers of "universal healthcare." Any government that attempts to guarantee healthcare must also control its costs. The inevitable next step will be to seek to control citizens' health and their behavior. Hence, Americans should beware that if we adopt universal healthcare, we also risk creating a "nanny state on steroids" antithetical to core American principles.

Other countries with universal healthcare are already restricting individual freedoms in the name of controlling health costs. For example, the British government has banned some television ads for eggs on the grounds that they were promoting an unhealthy lifestyle. This is a blatant infringement of egg sellers' rights to advertise their products.

In 2007, New Zealand banned Richie Trezise, a Welsh submarine cable specialist, from entering the country on the grounds that his obesity would "impose significant costs ... on New Zealand's health or special education services." Richie later lost weight and was allowed to immigrate, but his wife had trouble slimming and was kept home. Germany has mounted an aggressive anti-obesity campaign in workplaces and schools to promote dieting and exercise. Citizens who fail to cooperate are branded as "antisocial" for costing the government billions of euros in medical expenses.

Of course healthy diet and exercise are good. But these are issues of personal – not government – responsibility. So long as they don't harm others, adults should have the right to eat and drink what they wish – and the corresponding responsibility to enjoy (or suffer) the consequences of their choices. Anyone who makes poor lifestyle choices should pay the price himself or rely on voluntary charity, not demand that the government pay for his choices.

Government attempts to regulate individual lifestyles are based on the claim that they must limit medical costs that would otherwise be a burden on "society." But this issue can arise only in "universal healthcare" systems where taxpayers must pay for everyone's medical expenses.

Although American healthcare is only under partial government control in the form of programs such as Medicaid and Medicare, American nanny state regulations have exploded in recent years.

Many American cities ban restaurants from selling foods with trans fats. Los Angeles has imposed a moratorium on new fast food restaurants in South L.A. Other California cities ban smoking in some private residences. California has outlawed after-school bake sales as part of a "zero tolerance" ban on selling sugar products on campus. New York Gov. David Paterson has proposed an 18 percent tax on sugary sodas and juice drinks, and state officials have not ruled out additional taxes on cheeseburgers and other foods deemed unhealthy.

These ominous trends will only accelerate if the US adopts universal healthcare.

Just as universal healthcare will further fuel the nanny state, the nanny state mind-set helps fuel the drive toward universal healthcare. Individuals aren't regarded as competent to decide how to manage their lives and their health. So the government provides "cradle to grave" coverage of their healthcare.

Nanny state regulations and universal healthcare thus feed a vicious cycle of increasing government control over individuals. Both undermine individual responsibility and habituate citizens to ever-worsening erosions of their individual rights. Both promote dependence on government. Both undermine the virtues of independence and rationality. Both jeopardize the very foundations of a free society.

The American Founding Fathers who fought and died for our freedoms would be appalled to know their descendants were allowing the government to dictate what they could eat and drink. The Founders correctly understood that the proper role of government is to protect individual rights and otherwise leave men free to live – not tell us how many eggs we should eat.

If we still value our freedoms, we must reject both the nanny state and universal healthcare. Otherwise, it won't be long before the "Waistline Police" come knocking on our doors.

• Paul Hsieh practices medicine in the south Denver metro area and is a cofounder of Freedom and Individual Rights in Medicine (FIRM).