A new study has found that a bitter hops extract supplement helped participants lose six-and-a-half times more fat than a placebo, as more than 2.5 million people in the UK use weight-loss jabs and millions more are expected to pay for the newly approved Wegovy pill.
The supplement, which costs 75p per dose, contains a concentrated form of hops, the plant used in beer brewing. Dr Madusha Peiris, a neurogastroenterologist at Queen Mary University of London, said the bitter compounds found in hops appear to be particularly effective at activating satiety hormones, helping people feel fuller for longer.
The bitter hop extract, called Amarasate, appears to outperform weight-loss jabs, also known as GLP-1s, on certain measurements. Weight-loss jab users typically lose between three and five times more weight than those not on the drugs, but research suggests 20 to 40 per cent of that loss comes from muscle mass.
In the new study, funded by supplement firm Calocurb, participants taking the tablets lost weight without losing any muscle mass. The independent research, published in the peer-reviewed journal Obesity Pillars, followed 128 adults through a 24-week weight loss programme that included monthly lifestyle advice sessions on limiting unhealthy snacks, increasing protein intake and exercising more.
How the trial was run
Participants took a daily supplement containing either 500mg of bitter hop extract or a placebo, split across two major meals a day. Body weight, appetite control and self-reported cravings were recorded every four weeks.
By the end of the study, those taking the bitter hops extract had lost around 4.5kg of body fat, 3.9kg more than those taking the placebo. The researchers, from the Bioeconomy Science Institute in New Zealand, concluded the supplement could be a useful additional option for people struggling to lose weight through lifestyle changes alone, or for those who want to come off weight-loss jabs without regaining weight.
Dr Edward Walker, the study's lead author, said interventions that can address these issues, either as an alternative to GLP-1s for weight loss or as a post-therapy to prevent weight regain, may prove useful. Bitter hops has previously been shown to increase feelings of fullness, reduce cravings and help people eat less, though concrete evidence of its effectiveness had been limited until now.
Why bitterness matters
Experts say the bitterness of the supplement causes the gut to produce appetite-suppressing hormones similar to those triggered by GLP-1 drugs. Dr Peiris said the bitterness is key, noting that most people think taste happens only in the mouth, but the gut is also packed with specialised sensors that can detect compounds in the food people eat. When these sensors are activated, she said, they trigger the release of hormones that influence hunger and fullness, helping tell the brain when someone has had enough to eat.
The researchers noted that participants taking Amarasate experienced fewer overall food cravings and fewer cravings specifically for fatty, salty and savoury foods. Dr Peiris said food noise, repetitive thoughts about food that can drive snacking and overeating, is a big problem for many people struggling to maintain a healthy weight, and that it often stems from not producing enough of these appetite-suppressing hormones.
However, the researchers noted that around one in ten participants suffered uncomfortable side effects, including diarrhoea and nausea.
Limits of the findings
Experts caution there is not yet enough research to suggest supplements like this one could replace weight-loss drugs, particularly for patients with obesity-related conditions such as diabetes. Dr Peiris said the findings nevertheless highlight the importance of naturally stimulating the gut's appetite-control systems through diet, adding that a similar effect is seen in patients who eat a high-fibre diet, including foods such as nuts, seeds, pulses, legumes, oats and certain vegetables.
Dr Peiris said that as a gut scientist who studies nutrient-sensing mechanisms, it is encouraging to see human studies showing changes in appetite and appetite-regulating hormones, but that eating a diverse diet, particularly one rich in fibre, can have a similar effect because these nutrients also stimulate the same gut receptors.
