Women who follow a low calorie diet lose significantly less weight than men, a major diabetes prevention trial has found.

A multinational study that included Australian centres has found substantial gender disparities favouring men in risk factor responses among overweight people who follow a low calorie diet.

In the PREVIEW lifestyle intervention study 2020 overweight people (BMI >25) with pre-diabetes followed the low calorie Cambridge Plan Diet (3.4 MJ/810 kcal/daily) for eight weeks.

Study participants were recruited in eight centres, including the University of Sydney by co-researcher Dr Jennie Brand Miller (PhD)

While both sexes showed improvements in anthropometry, blood pressure and metabolic profile, weight loss was 16% greater in men than in women (11.8% vs 10.3%, respectively) Improvements in insulin resistance were similar in both sexes.

After adjusting for differences in weight loss, men had larger reductions in metabolic syndrome Z‐score, C‐peptide, fat mass and heart rate. Women had larger reductions in HDL cholesterol, fat‐free mass, hip circumference and pulse pressure.

Overall, women tended to show more ‘undesirable’ responses to a low calorie diet, said the authors of the study published in Diabetes Obesity and Metabolism.

“These findings are clinically important and suggest gender‐specific differences between men and women after weight loss,” they wrote.

Diabetes prevention diets might need to be designed depending on gender, they suggested

“It is of importance to investigate whether the greater reduction in free fat mass, bone mineral content, hip circumference and HDL-cholesterol in women after rapid weight loss is indeed beneficial or, rather, might compromise weight loss maintenance and future optimal/good cardiovascular health,” they added.

However, lead author Dr Pia Christensen, of the University of Copenhagen, Denmark, emphasised that the low-energy diet did result in the initial 10% weight loss needed to achieve major metabolic improvement in the first phase of a diabetes prevention program.

“Despite adjusting for the differences in weight loss, it appears that men benefitted more from the intervention than women. 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,” she said.