Free Prepackaged Meal Can Help Promote Weight Loss and Maintenance

Losing weight and keeping it off, for most people, means reducing their caloric intake and maintaing a calorie-reduced diet for as long as they plan to keep the weight off (a rare few can depend exclusively on exercise alone to lose and keep weight off – most of us can’t).

This means, they will either have to restrict their daily calories by basing their food choices on their total caloric content or by depending on someone else to providing them with meals that contain fewer calories than what they would normally eat (meal replacements or prepackaged meals).

The latter approach was now, for the first time, tested in a randomised clinical trial.

In a paper by Cheryl Rock and colleagues from San Diego, Tucson, Minneapolis and Portland, published last month in JAMA, the investigators studied the effect of a free prepared meal and incentivized weight-loss program on weight loss and weight loss maintenance in obese and overweight women.

A total of 442 women (BMI 25-40) aged 18 to 69 years were randomised to one of three two-year interventions:

1) A “usual care” group, where participants were provided consultation with a research staff dietetics professional, who provided publicly available print material that described dietary and physical activity guidelines to promote weight loss and maintenance at baseline and again at 6 months. Sample meal plans, recommendations to increase physical activity, and written materials and resources for strategies and skills (eg, reading food labels, estimating serving sizes, eating outside the home) were provided. This 1-hour session was followed by monthly check-in via e-mail or telephone, and progress and strategies were discussed in a follow-up counseling session at 6 months.

2) An “in-centre” group, where participants were offered free-of-charge weekly one-to-one counseling sessions, with follow-up telephone and e-mail contacts and Web site or message board availability. Program materials included free-of-charge prepackaged prepared foods as needed to achieve a meal plan.

3) An “telephone” group, where all counseling was conducted by phone, but the participants received exactly the same foods and program support as provided to group 2.

In groups 2 and 3, participants were encouraged during the initial period to follow a menu plan with prepackaged foods, which would provide 42% to 68% of energy. Over time, participants were transitioned to a meal plan based mainly on food not provided by the program, although participants could choose to include 1 prepackaged meal per day during weight loss maintenance.

Participants in groups 2 and 3 were also counseled to increase physical activity to 30 minutes of physical activity on 5 or more days per week.

The study was entirely funded and all prepackaged meals and program materials were provided free of charge by Jenny Craig.

It is perhaps also important to note that, although more than 90% of participants completed the study, only 24.6% of center-based and 39.2% of telephone-based participants continued with their weekly counseling sessions during the last six months of the study.

At the end of two years, the participants in the “usual-care” group had lost 2.0 kg (2.1% of their initial weight).

In contrast, the participants in the “in-centre” and “telephone” groups lost 7.4 kg (7.9%) and 6.2Kg (6.8%), respectively.

Thus, there is no doubt that the “Jenny-Craig” foods and programs were far more effective than the “usual-care” intervention.

However, as the authors point out, an important caveat is that although the participants in groups 2 and 3 of this trial followed the Jenny Craig program and received the prepackaged foods, all of this was provided to them free of charge.

The costs to paying participants would normally have included the $359 annual enrollment fees for a year-long premium plus membership in Jenny Craig as well as the the cost of Jenny Craig’s prepackaged food, which averages $100 per week. An additional $20 to $25 per week would have been needed for the recommended vegetables, and dairy foods. Thus, the first year would have cost participants around $4000 in foods.

For the second year of the program, when participants transitioned to their own foods, food costs would have averaged about $2200 for the year. Surprisingly, perhaps, these figures are not that much more than the estimated $124 per week that US consumers typically spend on food according to the Consumer Expenditure Survey.

Nevertheless, as the authors note, there may be:

…a major issue is the generalizability of these findings to the average patient. The results may be related in part to the economic benefits to the participants of providing food, as well as reimbursement for participating in clinic visits, and the low dropout rate in this study contrasts with the high attrition rates reported among weight loss program cohorts.

Nevertheless, the study demonstrates that the provision of (free) prepackaged meals together with (free) weekly in-person or telephone visits and (free) program materials are clearly more effective in helping patients achieve and maintain a clinically meaningful amount of weight than “usual” care.

Whether subjects were able to maintain any of this weight loss after discontinuing the trial and whether or not any of the participants were convinced enough of the value of the program to become paying customers of Jenny Craig is of course not mentioned in the sutdy.

But I am sure that the researchers are fully aware that It will be of considerable interest to check in again with the participants in this trial in a couple of years to see if there are any lasting or carry-over effects from the participation in this trial.

Whether or not this happens, I would certainly like to commend Jenny Craig on funding this study – this is not something that can be said for most commercial programs, which are often happier to rely on “before and after testimonial” (these results may not be typical) than on randomised controlled trials and peer-reviewed publications to market their services.

Edmonton, Alberta

Rock CL, Flatt SW, Sherwood NE, Karanja N, Pakiz B, & Thomson CA (2010). Effect of a free prepared meal and incentivized weight loss program on weight loss and weight loss maintenance in obese and overweight women: a randomized controlled trial. JAMA : the journal of the American Medical Association, 304 (16), 1803-10 PMID: 20935338