Extreme weight fluctuations linked to higher mortality in people living with heart disease

A new study has found that extreme weight fluctuations — both gain and loss — significantly increase the risk of death in individuals living with obesity and cardiovascular disease.

Researchers from Anglia Ruskin University (ARU) analysed data from 8,297 UK participants enrolled in the UK Biobank study. Over a follow-up period of nearly 14 years, they observed that both substantial weight gain and weight loss raised mortality risk, making this study "the first of its kind" to examine the impact of weight variability in this high-risk group.

The study found that individuals who gained more than 10kg (22lb) during the study period faced a three-fold increase in the risk of cardiovascular death and nearly double the risk of all-cause mortality compared to those who maintained a stable weight. Weight loss of more than 10kg was also linked to a 54 per cent higher risk of all-cause mortality, suggesting that both extremes of weight change may be harmful.

Lead author Dr Jufen Zhang, associate professor at ARU’s Medical Technology Research Centre said: "Maintaining a stable weight, even within the obese range, appears to be crucial for reducing mortality risk in patients with cardiovascular disease.”

She also urged caution regarding rapid weight loss treatments. "Clinicians should bear this in mind, particularly with regards to new drugs on the market that are lauded for delivering fast weight loss."

The study found that a higher body mass index (BMI), smoking, and past alcohol consumption were associated with a greater likelihood of significant weight gain. Additionally, younger individuals were more prone to major weight fluctuations.

Co-authors Prof Barbara Pierscionek and Dr Rudolph Schutte noted that while it was expected that weight gain would increase mortality risk, the strong association with weight loss was a striking finding.

The findings come at a time when obesity rates in the UK continue to rise. According to the Health Survey for England, the proportion of people living with obesity increased from 15 per cent in 1993 to 29 per cent in 2022, with more than two-thirds of those over 35 classified as living with overweight or obesity. The economic burden is also significant, with obesity estimated to cost the NHS £6.5 billion annually.

The study has been published in the BMJ journal Heart.