Low Carbs for Just Two Days a Week Spurs Weight Loss

Can you diet for just two days a week? You might be able to drop more weight if you cut back on carbs just two days a week.

British researchers found that women who essentially gave up carbs for two days and ate normally the rest of the time dropped about 9 pounds on average, as compared to the 5 pounds lost by women who cut back to around 1,500 calories every day, according to a new report presented at the CTRC-AACR San Antonio Breast Cancer Symposium.

The study's lead author Michelle Harvie, a research dietician at the Genesis Prevention Center at the University Hospital in South Manchester, England stated that, "We came up with the idea of an intermittent low-carb diet because it enables people to still have foods that are very satiating." "Also, there's a lot of evidence from other studies showing that restricting carbohydrates has the same effect as restricting energy."

Harvie and her colleagues were spurred to find a diet that would be easier for women to follow because research has shown that obesity and the changes it causes in the body increase the risk for breast cancer. "We know from our research in animal models that losing weight has the potential for reducing breast cancer risk," Harvie said.

The researchers followed 88 women for four months. All the women were at high risk for breast cancer based on their family histories. One third of the women were put on a Mediterranean-type diet that restricted calories to about 1,500 per day. A second group was told to eat normally most of the time, but two days a week to cut carbs and also calories to about 650 on those two days. The third group was also to cut carbs two days a week, but there was no calorie restriction on those days.

At the end of four weeks women in both of the intermittent dieting groups had lost more weight -- about 9 pounds -- than the women who ate low calorie meals every day of the week -- about 5 pounds.

Women in the intermittent dieting groups also had better improvement than daily dieters in the levels of hormones -- insulin and leptin -- that have been linked with breast cancer risk, Harvie said. And, yes, this is something you can try at home, Harvie said. You just need to dramatically cut back carbohydrates two days a week and try to eat sensibly the rest of the time, she added.

What that means, Harvie said, is that you can eat protein and healthy fats on the two low carb days, but skip bread, pasta, root vegetables like potatoes, carrots and parsnips to get to the 50g limit. The diet allows for one piece of fruit on the low carb days. Other foods on the menu include: nuts and green, leafy vegetables, peppers, mushrooms, tomatoes, broccoli, eggplant and cauliflower.

Presented at the CTRC-AACR San Antonio Breast Cancer Symposium Nov. 2011