Obesity and smoking habits.

SIR,-I have read with great interest the article by Dr. T. Khosia and Professor C. R. Lowe (2 October, p. 10) on smoking and obesity. Our results at the Institute of Directors Medical Centre (Table) do not show the same relationship. There is no convincing difference between any of the smoking classes. The figures have not been broken down into age groups, but we have previously shown that in our population age has little effect on the number of smokers and the amount they smoke.' There is a tendency for absolute weight to increase with age,2 but this does not seem to be true for relative weight, except perhaps for the over 60's.3 haviour in our patients may account for the lack of difference in relative weight between our non-smokers and heavy smokers. Those who exhibit moderation in non-smoking (1-19/day) have indeed got the lowest incidence of overweight-in agreement with Dr. Khosla and Professor Lowe. There is general agreement that stopping smoking usually leads to weight gain. In our population we have found that this is by no means a necessity. Of 222 men who had given up smoking at follow-up a year or more after their first visit 50 0% had the same weight (± 5 lb), 280%0 had gained weight, but 22 O0 had lost weight. This does not agree with weight difference between smokers