Increased portion sizes is widely recognized as a contributor to the obesity epidemic in Americans, and now a new research published in Obesity, the scientific journal of The Obesity Society, examines the effect of prepackaged, portion-controlled meals on weight loss.
The researchers found that when combined with behavioral counseling as part of a complete weight-loss intervention, a meal plan incorporating portion-controlled, prepackaged, frozen lunch and dinner entrees can promote greater weight loss than a self-selected diet.
‘Reduction in energy intake is a key factor to weight loss, but it can be difficult for most individuals with overweight or obesity to put into practice.’
"Participants who were prescribed twice-daily prepackaged meals lost about eight percent of their initial weight, compared to participants in the control group - who could select their own diets - who only lost about six percent," said Cheryl Rock, PhD, RD, lead researcher and Professor of Family Medicine and Public Health at the University of California San Diego School of Medicine.
"What's more, our study found that food satisfaction was comparable among all groups, which is a critical factor that may determine long-term usefulness of this strategy. We believe that removing the complexity of planning and preparing low-calorie meals was beneficial to the participants in the intervention."
To conduct the study, Dr. Rock and colleagues 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 (>25% energy), and the control group that was allowed to select their own meals.
All 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.
After three months, 74% of the participants eating the prepackaged foods had achieved a 5% weight loss, whereas only 53% 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.
Additionally, 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.
"Reduction in energy intake is a key factor to weight loss, but it can be difficult for most individuals with overweight or obesity to put into practice," said Martin Binks, PhD, Associate Professor of Nutritional Sciences at Texas Tech University and spokesperson for The Obesity Society. "This type of strategy is a step toward implementing effective, evidence-based solutions to obesity."
The biggest limitation to the study is the lack of detailed dietary intake data. Longer term studies that carefully measure adherence to this type of program would be beneficial.