Shedding excess kilos provides a healthy boost to the heart – even among so-called “yo-yo” dieters, researchers have said, with people who lose weight through healthy lifestyle programmes being less likely to develop cardiovascular disease or Type 2 diabetes.
The researchers, working with the American Heart Association (AHA), said these benefits last for at least five years and remain, even for those who regain the weight. That’s good news for yo-yo dieters, they added.
Previous studies suggested that fluctuations in weight increase the risk of premature death, reports StudyFinds.
For this latest study, the teams pooled data from 124 reports involving more than 50 000 participants.
Participants were an average age 51-years-old, with a body mass index of 33, categorised by experts as obese.
“Weight loss is often followed by weight regain, and people often fear that it’s pointless attempting to lose weight,” said study co-senior author Susan Jebb, a professor of diet and population health at the University of Oxford.
“This concept has become a barrier to offering support to people to lose weight. For people with overweight or obesity issues, losing weight is an effective way to reduce the risk of Type 2 diabetes and cardiovascular disease.”
These lower risk factors last for at least five years after the diet ended, with accompanying lower blood pressure, higher levels of good cholesterol, and less risk of developing cardiovascular disease or diabetes – even after regaining the weight.
However, she said, more information was necessary to confirm whether the potential benefits for yo-yo dieters persists.
Few studies have followed people for more than five years. The average tracking time has been 28 months.
“Most trials look at whether new treatments are effective and focus on weight change in the short-term rather than the effect on later disease,” Jebb said.
“Individual studies are often too small to detect differences between groups in the incidence of cardiovascular conditions because, fortunately, they affect only a small proportion of the whole group, and studies may not continue long enough to see the effects on ‘hard’ outcomes, such as a new diagnosis of Type 2 diabetes or a heart attack.
“Our findings should provide reassurance that weight loss programmes are effective in controlling cardiovascular risk factors and reduce the incidence of cardiovascular disease.”
Globally, estimates show being overweight and obese contributed to 2.4m deaths in 2020. The studies in the analysis included diet and/or exercise interventions, partial or total meal replacement, intermittent fasting, or financial incentives contingent on weight loss.
The findings were published in the AHA journal Circulation: Cardiovascular Quality and Outcomes.
Study details
Long-Term Effect of Weight Regain Following Behavioral Weight Management Programs on Cardiometabolic Disease Incidence and Risk: Systematic Review and Meta-Analysis
Jamie Hartmann-Boyce, Annika Theodoulou, Jason Oke, Ailsa Butler, Anastasios Bastounis, Anna Dunnigan, Rimu Byadya, Linda Cobiac, Peter Scarborough et al.
Published in Circulation: Cardiovascular Quality and Outcomes on 28 March 2023
Abstract
Background
Behavioural weight management programmes (BWMPs) enhance weight loss in the short term, but longer term cardiometabolic effects are uncertain as weight is commonly regained. We assessed the impact of weight regain after BWMPs on cardiovascular risk factors, diabetes, and cardiovascular disease.
Methods
Trial registries, 11 databases, and forward-citation searching (latest search, December 19) were used to identify articles published in English, from any geographical region. Randomised trials of BWMPs in adults with overweight/obesity reporting cardiometabolic outcomes at ≥12 months at and after program end were included. Differences between more intensive interventions and comparator groups were synthesised using mixed-effects, meta-regression, and time-to-event models to assess the impact of weight regain on cardiovascular disease incidence and risk.
Results
One hundred twenty-four trials reporting on ≥1 cardiometabolic outcomes with a median follow-up of 28 (range, 11–360) months after program end were included. Median baseline participant body mass index was 33 kg/m2; median age was 51 years.
Eight and 15 study arms (7889 and 4202 participants, respectively) examined the incidence of cardiovascular disease and type 2 diabetes, respectively, with imprecise evidence of a lower incidence for at least 5 years. Weight regain in BWMPs relative to comparators reduced these differences. One and 5 years after program end, total cholesterol/HDL (high-density lipoprotein) ratio was 1.5 points lower at both times (82 studies; 19 003 participants), systolic blood pressure was 1.5 mm mercury and 0.4 mm lower (84 studies; 30 836 participants), and HbA1c (%) 0.38 lower at both times (94 studies; 28 083 participants). Of the included studies, 22% were judged at high risk of bias; removing these did not meaningfully change results.
Conclusions
Despite weight regain, BWMPs reduce cardiometabolic risk factors with effects lasting at least 5 years after program end and dwindling with weight regain. Evidence that they reduce the incidence of cardiovascular disease or diabetes is less certain. Few studies followed participants for ≥5 years.
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