Burning to be slim

Demand for weight loss solutions is growing, driven by the rising number of people who are clinically obese (with a BMI of over 30) and the insistent desire for the all-important thigh gap on social media. Our celebrities are expected to bow to the mantra that size zero is not just desirable but required. Beautiful and already-slender Jennifer Lawrence was apparently requested to lose weight for her film role in The Hunger Games and men too are bombarded with images when lean muscle should not be obscured by a millimetre of fat.

Not surprisingly, there are a multitude of OTC weight loss products that claim to be able to help people lose pounds. Sadly, there is little or no evidence that any of these work although one exception is orlistat (marketed as Alli) which inhibits the product of an enzyme in the gut which allows the absorption of fat.  This non-absorption of fat, has an unfortunate side effect that it can cause diarrhoea. Orlistat is currently the only licensed weight loss drug in the UK. Recently the UK regulator has approved two new medicines for weight loss, although they are not yet on the market. One is a combination product containing bupropion, more widely known for its ability to act as an antidepressant and smoking cessation aid, and naltrexone, used in the management of drug and alcohol dependence. This ‘repurposing’ of drugs is often seen in weight loss treatments. For example, ongoing research is looking into whether two drugs originally developed for cancer treatment (beloranib) and an overactive bladder (mirabegron) may be safely used to help clinically obese people lose weight. These drugs are thought to rev up the metabolism, burning up calories more efficiently so they are not laid down as fat.

Many weight loss prescription drugs have come and gone over the years as side effects became a concern. Rimonabant, for example, a cannabinoid associated with psychiatric side effects, was withdrawn in 2008.

Worryingly, there is also a growing trend towards taking illegal drugs to aid rapid weight loss which can be bought over the Internet and are entirely unregulated.  Dinitrophenol (DNP) is an organic compound that can cause rapid weight loss but is linked to many deaths. It works by increasing metabolism resulting in heat production in cells via a process known as uncoupling. Even relatively small doses can be fatal. People can literally burn up inside.

It is banned in all countries but it is still available to would-be slimmers at the click of a mouse. Yes, some people do report instant results, but they put their long-term health at risk because DNP use results in hyperthermia, tachycardia, diaphoresis and tachypnoea, eventually causing organ failure leading to death.

There is no magic bullet for weight loss and drugs are not a long-term solution and should only be used by the overweight to kick-start a life change. Indeed, the only way to lose weight and keep it off is to combine regular exercise with a healthy lifestyle.