Somebody Call Jenny Craig?

From what I can recall, the quote, “somebody call Jenny Craig” was from the movie, Next Friday, featuring a not-quite ensemble cast including Ice Cube, Mike Epps and others.  To be fair, though the movie was a comedy, the phrase certainly had a pejorative spin.

Speaking of calling Jenny Craig, the results of a recent study involving Jenny Craig weight loss products was recently published in the Journal of the American Medical Association [1].  I would be remiss if I didn’t point out that the study was also funded by Jenny Craig.

Lead researcher, Cherly Rock of the Moores Cancer Center in California, conducted a 2-year long weight loss trial involving 442 female participants aged 18-69.  The study included both a weight loss and maintenance phase.   All of the participants had a body mass index over 25 at the start of the study.

Two different types of interventions  were  compared to a usual care group.  The intervention groups both received a free supply of Jenny Craig prepackaged food (yum?).  One group received telephone counselling while the other received in person counseling.  In both cases, the counseling was aimed at improving dietary habits as well as encouraging 30 minutes of exercise, five days per week.  The were scheduled on a weekly basis.

In contrast, the control group received just two 1-hour counseling sessions from a dietitian will instructions for eating a diet with a 500-1000 kcal deficit per day.  They also received an information package consisting of printout documents.

Study Results:

  • mean weight loss was 7.4 kg (95% confidence interval [CI], 6.1-8.7 kg) or 7.9% (95% CI, 6.5%-9.3%) of initial weight at 24 months for the center-based group
  • 6.2 kg (95% CI, 4.9-7.6 kg) or 6.8% (95% CI, 5.2%-8.4%) for the telephone-based group
  • 2.0 kg (95% CI, 0.6-3.3 kg) or 2.1% (95% CI, 0.7%-3.5%) for the usual care control group after 24 months (P < .001 for intervention effect).

What Are the Problems with the Study?

To start off with, this study employed rather poor methodology.  There was no blinding at all in the study design either for participants or observers.  What’s more is that the study did not detail what exercise instructions the control group was given, nor was there a comparison of either activity level during the study or any measure of calories consumed between groups.

The intervention groups also received weekly counseling sessions.  With three interventions (cardboard box food, exercise, and counseling) compared to 2 1-hour sessions with a dietitian, there’s no way of really know which component was effective in the intervention groups.  Another potential source of bias is that the study was funded by Jenny Craig.

What Does This Study Mean?

In short, yes a combination of sustained diet and exercise will result in weight loss.  Do you need to eat food from a cardboard box for a year or more to lose weight?  No.  Since this ‘research’ if you want to call it that was published in a reputable medical journal, you can expect to hear phrases such as “clinically proven weight loss” the next time you watch a Jenny Craig commercial on TV.  Participant food costs for the study would equate to $4080 per year according to the study.


  1. Rock CL, Flatt SW, Sherwood NE, Karanja N, Pakiz B, Thomson CA. 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. 2010 Oct 9.

9 thoughts on “Somebody Call Jenny Craig?

  • March 15, 2011 at 1:22 pm

    October 27, 2010 (Carlsbad, CA) – The Journal of the American Medical Association (JAMA) today released the findings of a two-year clinical trial examining the efficacy of Jenny Craig, a customized, individualized, structured and comprehensive weight management program, in helping overweight and obese women achieve average weight loss of 10% after one year and weight maintenance of more than 7.9% at the two-year mark. Importantly, researchers found those assigned to the Jenny Craig program, which included one-on-one weekly consultations, personalized nutrition and activity plans, adopted long-term healthier eating habits and meaningful health benefits for overall improved quality of life.

    This two-year study, following overweight and obese women randomly assigned to the Jenny Craig weight management program vs. usual care (also referred to as dieting on one’s own), demonstrated reduced biochemical risk factors that can lead to chronic disease including depression, diabetes, cancer and even stroke.

    The study also showed Jenny Craig promoted favorable changes in lipid, leptin and carotenoid levels, as well as improved cardiopulmonary fitness. Participation in the Program is also associated with improvements in the physical health scale of Quality of Life (QOL) and lower depression scores.

    The researchers attribute the participants’ success to personalization, motivation and constant support through one-on-one consultation. The approach of the Jenny Craig program encourages weight loss as well as addresses the various related health-issues that can plague obese individuals for a lifetime. The study findings provide a resource for health professionals nationwide who are seeking to recommend a clinically-proven weight loss program — without side effects — for their patients.

    “Obesity is a costly condition that can increase the risk for serious chronic diseases and premature death. The positive findings of this research have immediate implications for the millions affected by obesity and potentially far-reaching effects on public health and policy,” said Patti Larchet, CEO of Jenny Craig, Inc. “The results of this study highlight how the Jenny Craig program can significantly affect the obesity epidemic.”

    Principal investigator, Cheryl L. Rock, MD, PhD, RD, Professor of Family and Preventive Medicine in the Cancer Prevention and Control Program at the University of California at San Diego (UCSD), and her team followed a total of 442 overweight or obese women across four sites: UCSD, University of Arizona, Tucson; University of Minnesota, Minneapolis; and Center for Health Research, Kaiser Permanente Center Northwest, Portland, Oregon. The researchers sought to test whether Jenny Craig, a customized, individualized structured comprehensive weight loss program promotes greater weight loss and weight maintenance than usual care. The complete study, published today in the Journal of the American Medical Association (JAMA), found that at 24 months:

    Participants in the Jenny Craig center-based group (weekly in-person counseling) experienced a weight loss and maintenance of 7.4 kg or 7.9% of initial weight; The Jenny Craig telephone-based group (weekly one-to-one telephone counseling) experienced a weight loss and maintenance of 6.2% kg or 6.8% of initial weight; The usual care control group (two sessions with study dietitian, one at baseline; the other at 6 months follow-up) experienced a weight loss and maintenance of 2.0 kg or 2.1% of initial weight; The Jenny Craig enrollees experienced high compliance and tolerability; weight loss data was available for 92.1% of the Jenny Craig study participants (n=407) at the end-point.
    The 24-month trial also aimed to assess the effect of the program on selected biochemical factors (lipids, insulin, glucose, carotenoids, leptin, C-reactive protein (CRP), vitamin D) and cardiopulmonary fitness, with additional measures for Quality of Life (QOL) and eating attitudes and behaviors. Data was collected at 6-, 12-, 18- and 24-month endpoints.

    At baseline, the study sample consisted of 442 women aged 18 to 69 with an average age of 44 years, BMI 33.8(3.4) kg/m2, weight 92.1 (10.7) kg and waist circumference 108.6(9.6) cm. Study participants were recruited and randomly assigned to mirror the Jenny Craig client population. The Study was conducted under the guidance of Dr. Cheryl Rock and complied with all ethical and research protocols in place at the various study sites.

    Although participants in the two-year study were given complimentary Jenny Craig programs, researchers maintain this did not impact the research outcomes. “This study was conducted under the same rigors as any clinical trial which provides participants with complimentary products or services. Prior research shows, and the researchers’ observations confirm, individuals who voluntarily enroll and pay for a commercial weight loss program are more motivated and compliant than those who attempt weight loss on their own,” stated Lisa Talamini. “The key factors in the Jenny Craig program are individualization and one-on-one counseling which are evidenced by the high retention rate, 92.1%, at the end of the study.”

    For individuals seeking an alternative to costly medical and surgical interventions, Jenny Craig is a safe proven alternative for weight loss, weight maintenance and long-term health benefits.

    Jenny Craig, Inc., based in Carlsbad, CA, and owned by Nestlé, is one of the world’s largest weight management companies, with more than 725 company-owned and franchised Centres in the United States, Canada, France, United Kingdom, Australia, New Zealand and Puerto Rico.

    *Clients following our program, on average, lose 1-2 pounds per week.

  • October 28, 2010 at 7:57 am

    For all of the information that we have at our fingertips….why is it that we are still fooled by celebrity endorsements in tv commercials?

    Sometimes I really believe that the future predicted in the movie Idiocracy is coming true

    • October 28, 2010 at 6:57 pm

      I had a colleague who’s daughter bought him Nutrisystem or something like that. I was at his place once and his whole kitchen was filled with cardboard boxes of food. With these types of programs, they’re on a continuity model, so every week or whatever, they send more and more food. Unless you’re vigilant about eating their meals, they stack up pretty quickly.

  • October 28, 2010 at 5:38 am

    They obviously have a good marketing team! eating healthy and regular exercise should have better results. But then doesn’t cost money; just time.

    Patricia Perth Australia

  • October 27, 2010 at 2:53 pm

    I also think that is a really poor weight loss for that amount of time and money. I know that the Jenny Craig diet has been very successful for some people but I would feel cheated if I’d paid out that much on buying all their fancy food and only lost 7.4kg.

    Eat a sensible amount of real food and you’d lose a whole lot more than that over two years.

    But therein lies the problem – many can’t eat a sensible amount. The developed world has turned us into eating machines.

    I guess any weight loss has to be applauded but I’ll keep my money and go my own way!

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  • October 27, 2010 at 5:05 am

    7kg after 24 months!!!! C’mon. Why do these studies always ignore this obvious problem. 7kg after 24 months is crappy weight loss. It would have made no difference to me whether I had lost 7 or 2kg after 24 mths cause to me thats both a fail.

    • October 27, 2010 at 8:39 am

      Dan, that’s a lot of cardboard box food to eat for a not very significant amount of weight loss. It’s only 5kg more than their control group which only met twice with a dietitian.


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