The chance of an obese person attaining normal body weight is 1 in 210 for men and 1 in 124 for women, increasing to 1 in 1,290 for men and 1 in 677 for women with severe obesity, according to a study of UK health records led by King’s College, London. The findings suggest that current weight management programmes focused on dieting and exercise are not effective in tackling obesity at the population level.
The research, funded by the UK’s National Institute for Health Research (NIHR), tracked the weight of 278,982 participants (129,194 men and 149,788) women using electronic health records from 2004 to 2014. The study looked at the probability of obese patients attaining normal weight or a 5% reduction in body weight. Patients who received bariatric surgery were excluded from the study. A minimum of three body mass index records per patient was used to estimate weight changes.
The annual chance of obese patients achieving 5% weight loss was 1 in 12 for men and 1 in 10 for women. For those people who achieved 5% weight loss, 53% regained this weight within 2 years and 78% within 5 years.
Overall, only 1,283 men and 2,245 women with a BMI of 30-35 reached their normal body weight — equivalent to an annual probability of 1 in 210 for men and 1 in 124 for women. For those with a BMI above 40, the odds increased to 1 in 1,290 for men and 1 in 677 for women.
Weight cycling, with both increases and decreases in body weight, was also observed in more than a third of patients. The study concludes that current obesity treatments are failing to achieve sustained weight loss for the majority of obese patients.
Dr Alison Fildes, first author, said: “Losing 5 to 10% of your body weight has been shown to have meaningful health benefits and is often recommended as a weight loss target. These findings highlight how difficult it is for people with obesity to achieve and maintain even small amounts of weight loss.
“Once an adult becomes obese, it is very unlikely that they will return to a healthy body weight. Obesity treatments should focus on preventing overweight and obese patients gaining further weight, while also helping those that do lose weight to keep it off. Priority needs to be placed on preventing weight gain in the first place.”
— ADAPTED FROM REPORT BY KING’S COLLEGE, LONDON