Smoking behavior in individuals can vary, but in recent years, smoking behavior has been increasingly linked to obesity. This study aims to evaluate the association of BMI score, body fat with waist circumference and smoking status and intensity.

This is a mendelian randomization study that included 372,791 participants from the UK Biobank cohort and 74,035 participants from the TAG consortium.  The BMI score, body fat percentage, and waist circumference of the participants were considered and associated with the risk of current and past smoking, including the age of smoking initiation and the number of cigarettes smoked per day.

The analysis indicated that the incidence of smoking initiation increased with each standard deviation increment in BMI (OR 1.18). Moreover, each standard deviation increment in body mass index increased the smoking intensity by 0.88 cigarettes per day in the UK Biobank cohort and 1.27 cigarettes per day in the TAG consortium. Similar increments were also associated with an increase in body fat percentage and waist circumference in both the UK Biobank and TAG consortium cohorts.

The findings suggested that increased BMI, body fat percentage, and waist circumference were associated with higher smoking intensity in both the UK Biobank and TAG Consortium cohorts.

Ref: https://www.bmj.com/content/361/bmj.k1767