Packaged, pre-portioned meals help people lose more weight compared to allowing dieters to select their own food, a new study shows.

Over the years, the average portion size that people eat has increased, a factor being partly blamed for the nation’s obesity crisis. So a University of California San Diego research team set out to learn if packaged, portioned foods could help reverse this trend.

To conduct the study, the researchers assigned 183 study participants to three groups: one that was prescribed two prepackaged meals per day, one that was prescribed two prepackaged meals per day that were higher in protein, and a control group, which was  allowed to select their own meals.

All the participants met with a dietitian for a one- to two-hour personalized counseling session in which they determined their own weight-loss goals, received physical activity recommendations and learned behavioral strategies to help them achieve their goals.

The researchers found that, although all the groups lost weight, those that incorporated the pre-portioned foods into their plan lost eight percent of their weight compared to six percent for those allowed to chose their own meals.

Also, after three months, 74 percent of the participants eating the prepackaged foods had achieved a five percent weight loss, whereas only 53 percent of the control achieved that milestone.

The greater weight loss also led to a decrease in other cardiovascular disease risk factors like total cholesterol and LDL cholesterol for the participants consuming the prepackaged meals.

In addition, although meal satisfaction ratings were similar among all groups, and the groups that consumed the prepackaged meals expressed greater confidence in their ability to follow a meal plan long-term, says the study, which appears in Obesity, the scientific journal of the Obesity Society.