Junkfood Science: One little magic word

March 24, 2008

One little magic word

A single word can lead us to believe something that isn’t real. Nothing illustrates this better than a study in the current issue of the Journal of the American Medical Association. According to the press releases and media stories, this study showed that losing weight and keeping it off is possible.

Weight loss can be maintained and sustained, this study reported, when dieters have long-term support and regular contact from a professional health counselor. Said to be the largest weight loss maintenance study to date, the Weight Loss Maintenance Trial (MAINTENANCE) found that the services offered by the study’s authors — obesity disease case management and health coaching through online wellness programs — are the “key to successful, long-term weight management.” The authors said: “In conclusion, the majority of individuals who successfully completed an initial 6-month behavioral weight loss program maintained weight below their entry level after 30 additional months.”


What a funny little word to describe their findings. Most people think that “maintain” means to keep in a steady condition for a period of time. Few would have chosen that word to describe this:

This is the typical picture of a rebounding weight trajectory seen in weight loss studies. There was no weight loss maintained for 30 months, as you might have come away believing, upon hearing the reports. Even more remarkable, perhaps, is that this rebound was seen even among a select study population.

The authors acknowledged that weight loss interventions offer only short-term results and that virtually everyone regains the lost weight, so much so that claims of weight loss maintenance are not credible unless they’ve been demonstrated least 5 years. Even the study sponsor, “the National Heart, Lung, and Blood Institute has recommended that truly long-term benefit be assessed over at least 5 years.” Yet, like all diet studies, this one was designed to conveniently end before the expected weight regains looked really bad and in time for weight loss success to be reported.

There were other findings in this study that demonstrate the reality of weight loss interventions and weight maintenance, which make it valuable to take a closer look.

Study design

Four clinical centers authored and conducted this trial: Duke University, Johns Hopkins University, Pennington Biomedical Research Center, and Kaiser Permanente. During Phase I of this study, people were hand selected to participate in a weight loss program. The authors specifically tried to enroll 40% men and 40% African-Americans. All of the participants were young adults, between the ages of 25-45, and taking medications for blood pressure or cholesterol, but without any history of cardiac events or other health problems.

For phase II, the maintenance part of the study, those participants who successfully lost at least 8.8 pounds after 6 months were than randomized into two different weight maintenance programs.

One group was assigned personal contact from a professional health coach or nurse case manager. It was the disease management program model, consistent with recommendations of the Medicare Medical Nutrition Therapy Amendment Act of 2001, and based on behavioral change management. The participants had monthly phone contacts and met personally with their case manager every four months for 45-60 minutes.

A second group was entered into a web-based program, where interactive features enabled them to set goals and action plans, graph their weights, food intake and activity, receive motivation and social support, and were sent email reminders and 2 weekly automated telephone calls. This is the design sold through online health and wellness programs.

A third control group was more or less left to their own devices. They were given printed lifestyle guidelines with diet and exercise recommendations and met briefly with a study interventionist at the 12-month assessment visit.

Food intake was assessed by food frequency questionnaires at the beginning of the study, at the end of Phase I, and at the 12-month and 30-month assessment visits. Physical activity was measured by accelerometers worn for at least 10 hours a day for 4 days, including 1 weekend day, and used to estimate total weekly minutes of moderate to vigorous physical activity. Actual weights and measurements were taken by trained staff members every 6 months during the study.


Only 3 out of 5 people who participated in the weight loss program managed to successfully lose enough weight — a mere 8.8. pounds after 6 months — to go on to phase II of the study. So, 39% of the original study participants were dropped from the study before the maintenance part began and 3 died during the maintenance period. Among the remaining 1,029 participants, 36% were men, they had an average weight of 212 pounds, and nearly 2/3 were college-educated with household incomes ≥60,000.

At the end of Phase I, the dieters were engaging in an average of about 2 3/4 hours of vigorous-moderate intensity exercise per week (primarily brisk walking).

They were eating an average of only 1,596 kcal/day — nearly 1,000 calories fewer than the 2,510 kcal/day their bodies nutritionally required (based on their weights, BMI, genders, ages, and activity levels), according to the Adult Energy Needs recommended by Baylor College of Medicine (used by the 2005 Dietary Guidelines). Yet, they reported that this represented only about 325 kcal/day less than they had been eating before beginning this diet, indicating they had been restricting their intake and undereating for some time and likely had a recent history of dieting… diets that didn’t work. This would appear correct, as the only diet exclusion for this study was that the participants hadn’t lost more than 20 pounds in the past 3 months!

Here’s where it gets interesting.

There was no difference in the caloric intakes or the physical activities, or changes, among any of the groups throughout the 30-month ‘maintenance’ period. In other words, none of the expensive and intrusive interventions proved any more effective in encouraging behavioral changes than no interventions.

During the 30-month “maintenance” phase, the participants also actually continued to diet! Their caloric intakes rose only slightly (16 to 88 kcal/day) from their calorie restrictions during Phase I. At the end of the 30-month follow-up, the authors admitted the participants were still eating 231 to 326 calories per day less than they were at the start of the study — while they were all regaining weight. And remember, “changes in energy intake did not differ significantly between treatment groups.”

During the 30-month “maintenance” phase, their vigorous-moderate physical activity also dropped from their intense levels during Phase I, but only slightly. They continued to exercise 30 minutes/day, five days a week, gaining the health benefits attributed to physical activity. Some have suggested that activity might explain their regain, but it doesn’t. Their exercise times only dropped about 5 minutes a day during the maintenance period. Given their weights, ages and gender, this equates to a mere 161 calories a week. Nowhere near enough to compensate for the hundreds of calories less each day they were eating while continuing to diet trying to "maintain" a weight loss. This was not a blinded study and this select population appeared to be doing their best to comply with the study goals.

As we’ve seen in every weight loss study, weight regain is a biological reality for virtually everyone. Weight is not a matter of calories in-versus-calories out. Short term weight loss stunts are just that, temporary stunts. Sadly, unsuccessful dieters are typically blamed for “overeating” when they are not “overeating” as would be defined by any reasoned person, especially if nutritional health is our primary concern.

Examining the weight changes seen throughout the maintenance period, the authors reported there was “no significant differences between treatment groups.” In other words, none of the expensive and intrusive interventions proved any more effective in achieving long-term weight loss than no interventions. No mention was made of the adverse long-term health problems documented from repeated yo-yo dieting, losing and regaining weight.

Their comments and conclusions, however, were strikingly different from the study’s actual findings. They wrote:

The personal-contact intervention was effective across all subgroups… suggesting the potential for broad public health impact. Because most personal-contact intervention contacts consisted of monthly 10- to 15-minute telephone conversations, this is an efficient and practical mode of delivery.

[I]t is clear that preventing weight regain is extremely challenging. In fact, some observers have asserted that long-term success rates are so low that providing long-term behavioral weight loss treatments may ultimately be futile. However, our results suggest that clinically relevant weight loss maintenance is feasible. At the end of the study, more than 45% of those in the personal-contact intervention were still maintaining at least 4 kg of weight loss…

In conclusion, the majority of individuals who successfully completed an initial 6-month behavioral weight loss program maintained weight below their entry level after 30 additional months.

When you hear words like effective, success and maintain, remember that when it comes to obesity interests, just like results, definitions may vary.

© 2008 Sandy Szwarc

Disclosures. The authors report that the study was funded and sponsored by the National Heart, Lung, Blood Institute:

Some salary support for most individuals listed above was provided by the sponsor through the grants supporting this research, or, in the case of NHLBI project office, directly from the sponsor. Role of the Sponsor: The study sponsor participated in most aspects of the design and conduct of the trial and preparation of the manuscript.

The centers conducting this study offer weight management services, including case management and healthy lifestyle, wellness and fitness programs, with personalized behavioral and dietary education and support. For example, in addition to mainstream diets programs, such as Optifast meal replacement and Weight Watchers, Kaiser Permanente offers members personal health coaches and healthy lifestyle programs; and a full package of wellness products through its online service, Healthyroads. Through Healthyroads, people can access chiropractic care; acupuncture; massage therapy; fitness club memberships; herbs, vitamins and supplements; and health and fitness books and videos. Duke University offers a similar range of lifestyle and wellness programs, through its Duke Center for Living, Health & Fitness Center, Executive Health Programs and Lifestyle Retreats, Diet & Fitness Center, and Center for Integrative Medicine. Incorporated with clinical care, patients are encouraged to take control of their well-being through diet, exercise, positive lifestyle changes, and are offered complementary therapies, such as herbal medicine, acupuncture, massage, biofeedback, yoga, and mindfulness-based stress reduction. And Johns Hopkins Weight Management Center also offers a range of individualized programs.

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