Thin bus drivers deserve higher salaries than their overweight colleagues, a Lithuanian transport company decided in an unconventional move to promote healthy lifestyles slammed by trade unions.

"Over 100 bus drivers were weighed to calculate their body mass index," Elena Diniene, head of a local trade union in the northern city of Siauliai, said.

She explained that body mass index [BMI] was one of the criteria in a system of points that are decisive in salary rises.

A driver's health profile and blood pressure are among the other factors considered in determining pay rises, she said.

"We cannot call it nothing other than a mockery. If they [the company] do not reconsider we will appeal to the courts," she added.

"We just wanted to promote a health lifestyle," Vilius Lauzikas, director of Busturas, the transport company in question, told the Siauliu Krastas daily.

Lithuania's largest circulation daily Lietuvos Rytas ironically noted that the new rules meant that "drivers at work will feel like they're competing in a beauty pageant".

AFP