Sydney researchers have identified an oddity in weight loss, and they’re not sure how to explain it: women appear to lose more weight with weight loss drugs, whereas men tend to lose more weight with diets.

They found this oddity in data from three published clinical trials of weight loss drugs, and a previous meta-analysis on dieting.

The most dramatic results were found in a trial of semaglutide, which resulted in an 18.4 per cent weight loss for women, but just 12.9 per cent for men.

(Semaglutide is primarily a drug for Type 2 diabetes. But as The New Daily reported in June, it has become such a hit with overweight women that the Therapeutic Goods Administration (TGA) quietly issued a statement, directed at GPs, urging them to stop prescribing the drug for obesity management, because there was a shortage.)

Women may have more difficulty resisting cravings than men. Photo: Getty

Meanwhile, the meta-analysis on dieting found that in 10 out of the 11 included studies, men lost more weight than women, although women did lose weight.

The findings suggest “weight loss drugs may work differently in male and female bodies, but it’s unclear why men have more success than women when dieting”.

The study is by Alyssa Susanto, Associate Professor Samantha Hocking, and colleagues in the Faculty of Medicine and Health at the University of Sydney.

The findings, which haven’t been peer-reviewed or published, were presented this week at the International Congress on Obesity in Melbourne.

Why are men better on diets?

That men might benefit from dieting more than women isn’t new.

A 2018 study found that a low-calorie diet causes different metabolic effects in women than in men.

In the study of more than 2000 overweight participants with pre-diabetes who followed a low-calorie diet for eight weeks, men lost significantly more body weight than women, and they had larger reductions in a metabolic syndrome score, a diabetes indicator, fat mass, and heart rate.

Women had larger reductions in HDL-cholesterol, hip circumference, lean body mass (or fat free mass), and pulse pressure than men.

“Despite adjusting for the differences in weight loss, it appears that men benefitted more from the intervention than women,” said lead author Dr Pia Christensen, of the University of Copenhagen, in Denmark.

“Whether differences between genders persist in the long term, and whether we will need to design different interventions depending on gender will be interesting to follow.”

A 2004 study from Florida State University found that women may be “predisposed to succumb to the temptation to overeat”.

The study also suggested that exercise is a less effective method of appetite suppression in women than in men.

A 2005 study found cravings hit women harder than men: Women “are more often affected by problems with their eating behaviour, such as craving for special foods, than men”.

A 2009 brain-imaging study from the US Department of Energy’s Brookhaven National Laboratory found that men, but not women, are able to control their brain’s response to favourite foods.

The study “may help explain why rates of obesity and eating disorders are higher among women than men, and why women typically have more difficulty losing weight”.