Prescription Diet Pills - Supersized problems

The government’s medicines advisory agency this month recommended a new medicine that provides fresh hope in the fight against obesity.

Rimonabant, known by the brand name Acomplia, joins orlistat (Xenical) and sibutramine (Reductil) in the range of weight loss drugs available from doctors on prescription.

But Nicholas Finer, consultant in obesity medicine at Addenbrooke’s Hospital in Cambridge, cautions that while all these drugs have some effect, their ability to sustain weight loss is modest.
The bad news is that most other options are even less effective. For the growing number of obese people Finer sees in his clinic, he estimates that diet and lifestyle changes such as increased exercise achieve, at best, a 4 per cent reduction in weight over two years. He says that the most effective interventions are surgical, using gastric bands or bypasses. Such techniques can reduce weight by 30 per cent on average, and significantly cut the risk of cancer and other diseases.

He dismisses almost everything else as “snake oil”, its effectiveness not proved by clinical trials, including over the counter diet pills and supplements such as hoodia.

Orlistat, which in lower doses is available in the US over the counter and could in future be available in the UK, works in the stomach by preventing the body digesting some of the fat in food. The problem is that it can cause diarrhoea.

Sibutramine acts in the brain to enhance the effect of neurotransmitters that allow people to feel full more quickly and for longer. It can be associated with a dry mouth and constipation. Rimonabant blocks cannabinoid receptors in the brain, which help regulate food intake. Some patients have reported suicidal thoughts after taking it, so the drug is not recommended for patients suffering from depression.

Overall, the most disturbing aspect of the obesity epidemic is that it appears to be a one-way street: modern lifestyles and diets easily allow people to gain weight, but few are able to shed it in the long term.