In 2020, researchers observed a difference in weight loss between the sexes even when they stick to same amount of calories.
Men found it easier to lose weight than women, they revealed.
The findings came from The Direct Trial, a project led by Newcastle and Glasgow universities involving almost 300 men and women with type 2 diabetes.
They were put on a low-calorie (850 calories a day) diet to see if this would help them quickly lose 15 kg (about 2 st 3 lb) — a drop in weight it was hoped would reverse their diabetes.
‘Both men and women were on the same amount of calories so there should be no confusion,’ says Dr George Thom, a research dietitian at the University of Glasgow and co-author of the latest research.
The initial results, published in 2017 in The Lancet, found that half of the participants went into remission from type 2 diabetes.
But a new analysis (based on studying participants for another three years, published in the journal Diabetic Medicine) found that despite being asked to stick to virtually identical soups and shakes, there was a marked difference between the sexes.
After a year on the diet, the men had lost, on average, 11 per cent of their body weight. Women, by comparison, lost 8.4 per cent.
And the gap continued. After two years, men lost 8.5 per cent of their body weight and women lost 6.9 per cent. So why might this be?
‘We had asked people to stop all their normal foods and replace them with four formulated shakes or soups a day, so it’s really quite strict, and this ‘black and white’ approach to weight loss may suit men better,’ said Dr Thom.
In other words, they stick to it.
‘That’s possibly because the diet culture targets women from an early age, whereas men are more likely to feel the need to lose weight in middle age, so women are more diet-weary,’ he adds.
Men also typically carry more weight in visceral fat — the invisible fat around vital organs — whereas women typically have more subcutaneous fat (stored under the skin) around their thighs, bottom and hips.
This fat distribution pattern in females tends to be protective against a host of metabolic health problems — a combination of type 2 diabetes, high blood pressure and obesity, according to various studies which have shown that subcutaneous fat is associated with better health.
On the other hand, the visceral fat seen in men leaves them at greater risk, particularly from cardiovascular disease.
The result is that when men lose fat, it’s visceral fat, which improves metabolic risk factors leading to a reduced risk of type 2 diabetes, high blood pressure and obesity.
Women who diet are successfully losing subcutaneous fat, but without the same impressive results in either weight loss, the new study suggests, or marked health improvement.