Background Taking antiobesity medication can be a cost effective way to lose weight. Uptake is determined in part by a General Practitioner's decision to prescribe weight loss medication and, in part, by patient preference. It is probable that the latter may indicate a patient's readiness to lose weight.

Methods Analysis of cross-sectional data (from February 2003 to March 2011) from a population based prescribing database (∼1.75 million people) using an adjusted Poisson regression.

Results The number of antiobesity medications increased from 23.4 per 1000 population in 2004 to 30.7 per 1000 population in 2010 and was three times higher in female than in male subjects. Against this background, a marked seasonal variation in the number of antiobesity medications dispensed was evident (p<0.001), peaking in June/July with a trough in December/January (±8.0% peak to trough). The seasonal component was stronger in female subjects, ±11.2% peak to trough, compared with ±3.5% for male subjects.

Conclusions Obese patients, particularly women, increase their uptake of weight loss medication in the months leading up to the summer holiday period. The period prior to the summer may represent a time that health professionals could promote increased participation of obese patients in weight loss programmes.