The idea of a simple and convenient treatment for obesity is a good one - it’s just that we probably haven’t found it yet.

BBC News reports that a new weight-loss drug, lorcaserin, has been found to be safe in new study. Lorcaserin has been available in the US for several years under the name Belviq, but it has yet to be approved for use in Europe.

The new study found that over the course of 40 months, those using lorcaserin were three times more likely to lose five to 10 per cent of their body weight than those using a placebo. So it could be useful for a minority of obese people. But the average weight loss among the 12,000 people on the trial was just 4.4 kg. Of course, there may be a host of reasons why some people are more successful than others at losing weight when applying a particular treatment, from motivation to differences in individual biology. But lorcaserin is hardly a miracle cure. Where an obese person’s problem is regulating their appetite, an appetite-reducing drug may help. But clearly, appetite control isn’t the only factor in obesity.

From a health point of view, the dangers of obesity have been greatly exaggerated for decades. Most people who qualify as obese are merely a bit chubby and their weight will have no impact on their health. But the number of very seriously obese people, while small, is growing, even as the overall figures for obesity have plateaued. And regardless of health, many overweight people would simply prefer to be slimmer.

The usual recipe of dietary restriction and increased activity does work, but is often unsustainable. People simply feel a bit hungry all the time and once they achieve a target weight, it is easy to pile the weight back on again - often, with interest. While there are diets and execise regimes galore, the fact is that most fat people are inclined to yo-yo dieting rather than lasting weight loss. A pill that really helped people to lose weight would be a great boon. However, lorcaserin just isn’t the miracle cure we would love. But nor would such a pill be ‘cheating’.