Approximately 80 percent of smokers who quit smoking experience weight gain. Although the weight increase is generally modest, it can be significant in some patients and is a deterrent to smoking cessation for many women. Because studies of concurrent weight control interventions and smoking cessation programs have given disappointing results, Danielsson and colleagues studied the combination of nicotine gum and a very low energy diet to improve weight control during smoking cessation.

The authors recruited 287 women from 30 to 60 years of age who wanted to stop smoking and maintain their current weight. Eligibility criteria for the study included body mass index of 23 to 31, smoking history of at least 10 cigarettes per day for three years and history of at least one previous attempt to stop smoking that failed because of weight gain. Women were excluded from the study if they had serious cardiovascular, renal or hepatic disease, drug or alcohol abuse, pregnancy or any serious medical condition. Participants were randomly allocated to groups of 10 to 15 women who met 11 times during the 16-week study. All participants received nicotine gum (2 mg) and behavioral advice. If daily consumption of nicotine gum exceeded 20 pieces, they received 4-mg pieces. Gum was provided for three months, and advice was given on tapering its use. All study participants were encouraged to follow a balanced diet providing about 6.7 megajoules (MJ) per day, and a dietitian attended three of the group sessions. In addition, some of the groups were selected to be counseled on using an intermittent very low energy diet. Compliance with the diet was monitored by self-report plus analysis of urine for ketones. Smoking cessation was defined by self-report plus measurement of blood carbon monoxide concentrations. The study compared weight loss and success in smoking cessation between women assigned to the intermittent very low energy diet group and those provided with more conventional advice.

After 16 weeks, one half of the women in the diet group had stopped smoking, compared with 35 percent of the women in the control group. By 12 months, 28 percent of the women remaining in the diet group were still not smoking compared with 16 percent of the control group. Compliance with the very low energy diet was initially 75 percent, but dropped to 31 and 18 percent during weeks 6 to 8 and 12 to 14, respectively. At 16 weeks, the diet group had lost on average about 2 kg, whereas the control group gained an average of 1.6 kg. The diet group reported significantly lower ratings on mood symptom scores but reported headache more frequently than the control group. No women withdrew from the study because of adverse effects.

In this study, the smoking cessation rate was 28 percent at 12 months for patients in the diet group, significantly better than the 16 percent achieved by the control group and the 19 percent reported by other studies. Women on the very low energy diet reported less craving for cigarettes and decreased appetite. These findings may be effects of acidosis. By one year, no significant difference existed in weight gain between the groups, but both groups gained less than generally reported during smoking cessation. Nicotine gum, support and a very low energy diet appear to be effective in avoiding weight gain during smoking cessation in women who have previously resumed smoking because of concerns about weight gain.