Study leader Dr. Anne McTiernan of the Fred Hutchinson Cancer Center said the study involved 123 overweight-to-obese postmenopausal Seattle-area women ages 50-75.
The women were randomly assigned to either a diet-alone intervention with a goal: 1,200 to 2,000 calories a day, depending on starting weight, and fewer than 30 percent of daily calories from fat, or diet plus exercise with the same calorie and fat restrictions plus 45 minutes of moderate-to-vigorous exercise per day, five days a week. The women, who received nutrition counseling, were not given any specific instructions or recommendations about snacking. For the purposes of the study, a snack was defined as any food or drink consumed between main meals.
The findings, scheduled to be published in the December issue of the Journal of the American Dietetic Association, found mid-morning snackers lost an average of 7 percent of their total body weight while those who ate a healthy breakfast but did not snack before lunch lost more than 11 percent of their body weight.
"We think this finding may not relate necessarily to the time of day one snacks, but rather to the short interval between breakfast and lunch. Mid-morning snacking therefore might be a reflection of recreational or mindless eating habits rather than eating to satisfy true hunger," McTiernan said in a statement.