The finding goes against current guidelines which recommend patients try to quit smoking before attempting weight-loss.
A meta-analysis of data from 2,233 smokers in 10 studies found that women who did both were 29 per cent more likely to have successfully stopped smoking at three months than those receiving smoking cessation treatment alone. They were also 23 per cent more likely to quit in the long term.
Women receiving weight control and smoking cessation treatment also gained 2.5 pounds less on average in the long term than women given smoking treatment alone.
Meanwhile, researchers in France and the US have discovered high levels of bacterial pathogens in cigarettes.
DNA analysis of four popular brands found over 90 per cent contained bacteria including Acinetobacter, Bacillus, Burkholderia, Clostridium, Kelbsiella, Pseudomonas and Serratia. Some contained Campylobacter, Enterococcus, and Staphylococcus.
The researchers warn that these will enter smokers' respiratory systems, leading to both infectious and chronic illness.