Wondering why people often gain weight after quitting smoking? It is because of appetite-suppressing chemicals used in cigarettes.
According to internal industry documents dating from 1949 to 1999, British and American tobacco companies deliberately added powerful appetite-suppressing chemicals to cigarettes to attract people worried about their weight.
Chemical additives are just one of several strategies successfully used by tobacco companies over the past 50 years to convince people that smoking makes you thin.
The presence of appetite-suppressing chemicals could help explain why smokers who quit often gain weight, according to Swiss researchers in the European Journal of Public Health.
They have called for stricter rules on tobacco additives amid suggestions that sensitive documents are being removed from databases by the industry to avoid disclosure.
"We don't know if appetite-suppressing molecules are still added, because compliance with additive regulations is poor and sensitive internal documents are usually shredded," the Independent quoted Professor David Hammond, a tobacco industry expert at Waterloo University, Ontario, Canada, as saying.