Rapid weight loss may be more effective than gradual methods, new research suggests, directly challenging the long-held assumption that slower, steadier approaches produce better long-term results. Presented at the European Congress on Obesity in Turkey, the study found that people who shed pounds quickly not only lost more weight initially but were also more likely to keep it off a year later.
The findings contradict conventional wisdom that gradual weight loss is superior for sustained outcomes. Among 284 obese adults analysed by researchers from Norway, those who followed a rapid weight loss programme lost an average of 12.9 per cent of their total body weight during the initial 16-week phase, compared with 8.1 per cent for those on a gradual plan. After a full year, the rapid group maintained a loss of 14.4 per cent, while the gradual group lost 10.5 per cent.
The study divided participants into two distinct programmes. The rapid weight loss group followed a structured 16-week plan with specific calorie restrictions: 1,000 calories per day for the first eight weeks, 1,300 for weeks nine to 12, and 1,500 for the final four weeks. By contrast, the gradual weight loss group was advised to cut their daily intake by 1,000 calories, with participants self-reporting consumption of around 1,400 calories per day. For context, the NHS notes that the average man needs 2,500 calories a day and the average woman 2,000. After the 16-week weight loss phase, both groups took part in an identical 36-week programme designed to prevent weight regain.
“Among adults with obesity, participation in a structured rapid weight loss programme resulted in significantly greater weight loss at one year,” the authors wrote. Lead author Dr Line Kristin Johnson, from Vestfold Hospital Trust in Norway, said the results “clearly challenge the prevailing belief that slow and steady gradual weight loss is necessary to prevent weight regain and reduce obesity-related complications.” She added that rapid weight loss, when provided within a controlled and professionally supervised setting, “may represent a more effective method than gradual weight loss for reaching key body weight targets associated with reduced obesity-related health risks.”
Dr Marie Spreckley, research programme manager at the University of Cambridge, called the study important because it “challenges the longstanding assumption that gradual weight loss is superior for long-term outcomes.” She said the work adds to growing evidence that rapid weight loss, “when delivered safely and appropriately within a structured programme, can be an effective obesity treatment strategy and should not automatically be considered less sustainable than gradual weight loss.”
Dr Johnson also highlighted the wider public health implications, noting that many people with obesity cannot access or afford medical or surgical treatments. The results, she said, support the potential of effective, commercially available weight reduction programmes to help reduce the burden on healthcare systems. Official figures show that in England, nearly two-thirds of adults are overweight or living with obesity, with prevalence rates climbing over the past three decades. The annual social cost of obesity in the UK has been estimated at £58 billion, with NHS expenditure on obesity-related conditions running into billions of pounds each year.