Researchers at the Miriam Hospital in Providence, R.I., found 80 percent of the 44 patients randomly assigned to start with the "olive oil diet" lost more than 5 percent of their baseline weight.
Among those who started with the more conventional diet recommended by the National Cancer Institute, 31 percent lost more than 5 percent of baseline weight. Both 1,500-calorie diets were followed for eight weeks.
The olive oil diet, developed by Mary Flynn, a research dietitian at Miriam, included extra virgin olive oil or nuts at each meal, three servings of fruit and unlimited vegetables daily. Also included in the diet were: whole grains, beans, limited poultry and fish, but no red meat or polysaturated fats.
The study, published in the Journal of Women's Health, also found 19-of-22 patients eligible for six-month follow-up chose to continue with the olive oil diet -- because they said it was more satisfying and affordable. All 19 either maintained weight loss or lost more weight.
Flynn developed the olive-oil diet because even moderate weight gain during breast cancer treatment has been associated with an increased risk of cancer recurrence.