A scant few of the 2,267 US adults polled online by Harris Interactive early last month said employers should be allowed to fire someone who is unwilling to lose weight (four percent) or stop smoking (seven percent).
But around one-third of poll respondents said employers should be allowed to require staff to attend smoking cessation sessions or weight-loss programs.
"Employers have been making headlines recently for adopting stricter wellness policies in order to control healthcare costs," Harris Interactive's head of healthcare research, Katherine Binns, said in a statement.
"Companies such as Scotts (gardening) and Weyco (healthcare) have fired employees who tested positive for nicotine," the statement said.
A Massachusetts man last year sued Scotts for firing him for smoking on his own time, a report in the Boston Globe said.
His suit said he was unfairly sacked for "engaging in legal activities away from the workplace," the Globe report said.
Michigan-based Weyco instituted a policy in 2005 that allows employees to be laid off if they smoke, regardless of whether they engage in the habit at work or at home.
The company subsequently fired four employees who refused to be tested for nicotine, press reports said, with other reports saying Weyco staff members were fired after tests showed they had nicotine in their blood.
The poll conducted for The Wall Street Journal also showed that the number of Americans who feel the obese and smokers should pay higher healthcare premiums than their non-smoking and slim counterparts was significantly down form last year.
Thirty-seven percent said it was fair for people with unhealthy lifestyles to pay more for health insurance than their healthier counterparts, compared to 53 percent last year.
Eight out of 10 of those who said the unhealthy should carry a bigger health insurance burden also said it was unfair to ask people with healthy lifestyles to subsidize those who choose to smoke or pile on the pounds.
Three-quarters of those polled said they believed higher insurance premiums for unhealthy living could encourage people to live more healthily.