Despite best efforts, keeping weight off after losing it remains a significant challenge for most people. Studies show that in 80–95% of cases, individuals regain the weight they lost over time. This isn’t necessarily due to a lack of willpower, but rather the body’s biological programming. Hormonal shifts, particularly reductions in leptin – the hormone that signals fullness – and slower metabolic rates, often persist long after weight loss, making maintenance difficult.
A notable example is Danny Cahill from the TV show The Biggest Loser, who lost 108kg (approximately 238lbs) during the show but regained nearly half of it despite maintaining a strict diet. Research on former contestants revealed that their resting metabolic rates had significantly dropped and didn’t return to pre-diet levels, meaning their bodies burned fewer calories at rest. Additionally, their leptin levels remained low, increasing hunger and cravings.
Recent studies suggest that fat cells may retain a “memory” of past obesity through epigenetic changes, making the body more prone to regain weight. This memory can linger even after bariatric surgery, and similar traces have been found in immune and potentially brain cells. The implications are that weight regain may be biologically hardwired, especially in those who have experienced multiple cycles of weight loss and gain, known as yo-yo dieting.
Genetics also play a substantial role, with up to 70% of obesity risk linked to inherited traits. Environmental factors, such as access to healthy food and opportunities for physical activity, further complicate weight management.
While yo-yo dieting has been linked to inflammation and health risks in some studies, outcomes vary widely between individuals. Experts advise against extreme diets or exercise regimes, which may be unsustainable and counterproductive in the long term. Instead, moderate lifestyle changes—such as improved sleep, stress management, and a focus on whole, unprocessed foods—are recommended.
For some, medical interventions like weight-loss drugs or surgery may be necessary. The key, according to experts, is finding a personalised, sustainable approach that supports long-term wellbeing rather than short-term fixes.
