Swedish and American researchers have found that yo-yo dieting can more than double the risk of developing kidney cancer.
Yo-yo dieting, also known as weight cycling, is a repeated loss and gain of body weight due to excessive dieting.
Researchers studied 140,057 women aged between 50 and 79 for almost eight years to study the consequences of yo-yo dieting and compared women average waist size to those with the large waistlines.
The study found that 'weight cycling' as personified by Spice Girl Geri Halliwell along with a large waistline pose high risk in the development of the kidney cancer in older women than just obesity.
Scientists found that women with larger waist to hip ratios were at 80 per cent increased risk of developing a type of kidney cancer known as renal cell carcinoma (RCC).
Researchers noted that it was safer for women to gradually put on weight with growing age rather than shred weight through strict dieting.
The authors suggested many reasons relating yo-yo dieting and large waistlines to kidney cancer and pointed out earlier studies that linked weight cycling to increased incidence of high blood pressure, another risk factor for RCC.
Researchers also explained that frequent weight fluctuations might lead to kidney damage by stirring up metabolic or functional changes that increase cancer susceptibility.
Dr Colin Waine of the National Obesity Forum insisted that yo-yo dieting was unhealthy as constant weight fluctuation does not allow the body to settle.
"Yo-yo dieting is never a healthy thing to do because the body never gets a chance to settle. It knocks the metabolism all to hell, which is bad for you in many ways," the Daily Mail quoted Waine, as saying.
The findings of the study were published in the American Journal of Epidemiology.