How worried should you be about outgrowing your old jeans?

Have you dusted off a pair of jeans you wore aged 21 lately and seen if they still fit? Because a British expert in diabetes has suggested that if you can’t slip comfortably into your old clothes, then you are probably “carrying too much fat” – and could be at risk of type 2 diabetes.

Professor Roy Taylor, from Newcastle University, made his comments while presenting data from a new study to the European Association for the Study of Diabetes. He has studied the disease for more than 43 years and is the author of a bestselling book, Life Without Diabetes: The Definitive Guide to Understanding and Reversing Type 2 Diabetes.

The data he referred to came from a study in which eight of the 12 people in the trial – who were of a “normal” weight – managed to “get rid” of their type 2 diabetes by losing 10 to 15 per cent of their body weight. Taylor said the results “demonstrate very clearly that diabetes is not caused by obesity but by being too heavy for your own body”.

It is part of an important message on treating – and preventing – type 2 diabetes, a disease nearly 3.5 million people in the UK have, along with 1 million more who live with it but do not know it, and a further 7 million who are at risk of developing it. In Australia, almost 2 million people have diabetes.

But that message was lost when Taylor’s comments were received with derision, and #at21 started trending on Twitter. Many women questioned how useful it was to talk of jean size when their bodies had been through lifestyle changes, fertility treatments, pregnancy, childbirth and child-rearing.

For instance, despite having two babies, if I pulled on the pair of jeans I owned when I was 21, I’m not sure they would stay up. Like many students, I was living on a diet of takeaways, white carbs and cheap wine. It was only finding a later love of running, and a more nuanced understanding of nutrition, that saw my waist measurement decrease.

The message Taylor is normally so good at communicating is that the reason many of us are developing type 2 diabetes is not necessarily linked to obesity. One in two people who develops type 2 diabetes has a body mass index lower than 30.

Research suggests that minimal amounts of excess abdominal fat can be an important factor behind the development of insulin resistance and type 2 diabetes. So what can we do about it?

One reason for increased abdominal fat could be the genes we inherit. A study in the journal Nature in 2019 found that genetic variants determine where your body fat is distributed: in effect, your genes, not your jeans. But it also noted that lifestyle factors played a role, and these can prove harder to control as you reach midlife.