An intermittent low-carbohydrate diet spur weight loss and lower blood levels of insulin, a cancer-promoting hormone, more efficiently than standard dieting, a new study has suggested.
Researchers at Genesis Prevention Centre at University Hospital in South Manchester, England, found that restricting carbohydrates two days per week may be a better dietary approach than a standard, daily calorie-restricted diet for preventing breast cancer and other diseases, but they said further study is needed.
"Weight loss and reduced insulin levels are required for breast cancer prevention, but [these levels] are difficult to achieve and maintain with conventional dietary approaches," said Michelle Harvie, a research dietician.
Harvie and her colleagues compared three diets during four months for effects on weight loss and blood markers of breast cancer risk among 115 women with a family history of breast cancer.
They randomly assigned patients to one of the following diets: a calorie-restricted, low-carbohydrate diet for two days per week; an ‘ad lib’ low-carbohydrate diet in which patients were permitted to eat unlimited protein and healthy fats, such as lean meats, olives and nuts, also for two days per week; and a standard, calorie-restricted daily Mediterranean diet for seven days per week.
Data revealed that both intermittent, low-carbohydrate diets were superior to the standard, daily Mediterranean diet in reducing weight, body fat and insulin resistance.
Mean reduction in weight and body fat was roughly 4 kilograms with the intermittent approaches compared with 2.4 kilograms with the standard dietary approach.
Insulin resistance reduced by 22 percent with the restricted low-carbohydrate diet and by 14 percent with the ‘ad lib’ low-carbohydrate diet compared with 4 percent with the standard Mediterranean diet.
"It is interesting that the diet that only restricts carbohydrates but allows protein and fats is as effective as the calorie-restricted, low-carbohydrate diet," Harvie added.