Researchers say a new drug found to cut body weight by up to 20% is a 'game-changer' in the fight against obesity.
Semaglutide works by hijacking the body's own appetite regulating system in the brain, leading to reduced hunger.
The average weight loss in the study was almost 2.5 stone.
Professor Luke O'Neill said this could also help with coronavirus risk-factors.
"There's a massive effort in the pharmaceutical industry to come up with drugs that see obese people lose weight... not much has worked.
"This drug has seen a 20% decrease in body weight.
"Nearly 2,000 patients were in the trial. For the first time there's a medication you can use to help people who are severely obese. For COVID, obesity is a risk factor.
"There've been loads of trials with anti-obesity approaches, that have worked a bit. But this one clearly works."
The double-blind trial enrolled 1,961 adults with a body-mass index of 30 or greater for 68 weeks of once-weekly doses of Semaglutide or a placebo.
However there was also what researchers call "lifestyle intervention".
'Greater improvement'
It found that the mean change in body weight was -14.9% in the Semaglutide group, as against -2.4% in the placebo group.
"More participants in the Semaglutide group than in the placebo group achieved weight reductions of 5% or more", the study says.
"Participants who received Semaglutide had a greater improvement with respect to cardiometabolic risk factors and a greater increase in participant-reported physical functioning from baseline than those who received placebo", it adds.
While there were some common side effects, such as nausea and diarrhea, these subsided with time.
The study has been published in the New England Journal of Medicine.
The trial was funded by Danish healthcare company Novo Nordisk.
The firm employs about 44,000 people in 80 countries, including Ireland, and markets its products in around 170 territories.
It has already filed for regulatory approval of the drug in US from the Food and Drug Administration (FDA).
Mads Krogsgaard Thomsen is executive vice president and chief scientific officer of Novo Nordisk.
He said: "Obesity is associated with a wide range of serious complications, yet many healthcare providers still do not have sufficient medical options available to help people with this chronic disease.
"We are excited about the regulatory filing of Semaglutide 2.4 mg in the US and we believe once-weekly Semaglutide 2.4 mg has the potential to transform the medical management of obesity."
