You want other studies? The Guardian article sets it out! Doesn't seem like poor reporting to me.
The study, led by academics at the University of Oxford and published in the BMJ, included a review of 37 existing studies regarding weight loss medication, involving 9,341 participants. The average duration of weight loss treatment being 39 weeks while the average follow up period was 32 weeks.
On average, weight was regained at a rate of 0.4kg per month for people who had stopped taking the medication, the analysis found, with participants returning to their original weight within an average of 1.7 years after stopping any type of weight loss medication.
Specifically, people on any kind of weight loss medication lost an average of 8.3kg during treatment, but regained 4.8kg within the first year.
The rate at which weight was regained after stopping these medications was almost four times faster compared with behavioural programmes, which may include a specific diet or physical activity plan, regardless of the amount of weight that was lost during treatment.