Sunday, April 18, 2010

Mentor Support: an unsung key predictor of weight loss and weight loss maintenance There's one weight loss study that somehow has been in the public eye since 2003. Each time a version of its data gets published, it gets media attention for showing that LOTS of exercise helps maintain weight loss. Now from my reading of that data, that's actually kind of a misrepresentation of the findings in the paper. There are THREE factors that impact weight loss maintenance: caloric restriction (1200-1500kcals), 270-300mins of (vigorous) exercise a week AND (the under reported component) regular human contact intervention about compliance with the protocol. Finally, in yet another paper about this study, this later part of the work is being highlighted a bit more in the paper "Contribution of Behavior Intervention Components to 24-Month Weight Loss." I find it fascinating that such an interesting predictor of success - along with the more familiar caloric reduction - has been so seemingly downplayed in favor of hours of exercise.

Last year (2009), discussion of a second paper (published July 2008) on a 2 year study of obese women losing weight generated lots of attention.  In particular, Time focused on one aspect of the study, calling their piece "The Myth of Moderate Exercise." They focused on the finding that, in a trial of 201 obese women ("conducted between December 1999 and January 2003") who took off and kept off 10% of their body, did so by exercising at twice the amount of time recommended by the CDC (center for disease control), and by doing vigerous - not moderate - work.

A less well cited piece on the study at WebMD did make a bit more about the social aspect of the study that was seen to contribute to participants' ongoing success. One more even less cited post at, unlike Time, got it, too:
But even among this group who sustain 10 percent weight loss, exercise may not be the only thing they did to have the effect.   These people also completed more phone calls with the research staff and engaged in more eating behaviors recommended for weight loss and had a lower intake of dietary fat.
This was the second time this same study data had garnered attention for the reason Time made primary. Back in 2005,  WebMD published a story called "how much exercise sparks weight loss." It focused on the data that showed that the women who exercised for 4.5-5 hours a week, at an overall vigorous intensity, lost the most weight. This was the first time the full study data had been taken out for a walk - this time at a presentation at the North American Association for the Study of Obesity’s annual scientific meeting, Vancouver, Canada, Oct. 15-19, 2005.  Prior to this, a one year version of the study, with pretty much the same findings at the 12 month point was reported in 2003 in the Journal of American Medical Association. Gotta say, i am amazed at the longevity of this data set. It's a lesson for academics about how much information one can get from a rich data set.

Indeed, here's the latest version: April, 2010, Journal of the American College of Sports Medicine, "Contribution of Behavior Intervention Components to 24-Month Weight Loss."

Oh, and just a few months before this April 2010 version of the data,  the American College of Sports Medicine put out a press release taking "strong exception to assertions [in that original Time Article?] that exercise can inhibit weight loss by over-stimulating the appetite." The key person cited  in the PR is John Jakicic, author of the above study and who also just happens to "[chair] a committee on obesity prevention and treatment for the American College of Sports Medicine (ACSM) and helped write an ACSM Position Stand on strategies for weight loss and prevention of weight regain for adults."

Naturally, the ACSM statement says exercise helps maintain weight loss And to that end, quotes an awful lot of Jakicic's singular study's findings. Now, that all sounds great, but let's face it, (1) this cohort was 201 obese women, and (2) the ACSM may have just a little invested in celebrating the importance of exercise. They were burning off 1800+ calories with exercise AND living on calorie reduced diets AND were still, after two years, considered overweight. So their health had certainly improved, but if nothing else, this cohort shows that losing weight from an obese state takes long, hard graft. But it also seems to benefit from something else that may be just as necessary, and that's the human expert support.

Telephones: The Secret Ingredient?
Just to be clear, i'm in no way suggesting that exercise doesn't help with weight loss. Recently i've discussed just two of many studies - one on HIIT, one on cardio - that shows benefit for fat loss. But what i am intrigued by, and what's been in the published data since day one, is the fact that exercise and BIG calorie restriction were not the only key factors in getting the weight off, and perhaps just as importantly, keeping it off. While the researchers have made this point repeatedly in the data, it's one they themselves seem reluctant to foreground, even in the latest study.  Here's the abstract:

Sustaining weight loss at the long term is difficult.
Purpose: To examine if eating behaviors, physical activity levels, and program participation influence ones ability to achieve ≥5%, ≥7%, and ≥10% weight loss during a period of 24 months.
Methods: Data from 170 overweight and obese women (body mass index = 32.7 ± 4.2 kg·m−2) were analyzed in this study. All women followed a standard 24-month behavioral weight loss program in which they were instructed to decrease caloric intake and increase physical activity levels. Eating behaviors, body weight, and physical activity levels were assessed at baseline and at 6 and 24 months. Program participation was evaluated by the percentage of group meetings attended and the percentage of telephone calls completed with an interventionist. Three separate stepwise linear regression analyses were performed to identify variables that were predictive of ≥5%, ≥7%, and ≥10% weight loss at 24 months.
Results: The percentage of telephone calls completed and change in weight loss eating behaviors predicted ≥5% (r2 = 0.16), ≥7% (r2 = 0.14), and ≥10% weight loss (r2 = 0.10) at 24 months. However, the change in physical activity levels from baseline to 24 months was only predictive of weight losses ≥10% (r2 = 0.11).
Conclusions: Behavioral factors, such as adopting healthy eating behaviors and telephone contact time, are important components that assist individuals in achieving weight losses ≥5%. However, high levels of physical activity play a more prominent role in sustaining weight losses ≥10%. Therefore, innovative strategies to enhance long-term exercise adherence should be developed.
That's an interesting conclusion. It separates out achieving a weight loss target to sustaining a weight loss target. It says, if i'm reading it correctly, that eating behaviors and social expert support about the progress in the program are potent factors for getting to weight loss equal to 5% of total weight, or for that matter to anything above 5%. To *sustain* weight loss that is equal to or greater than 10%, however, high level physical activity has to be there. At least if you're an obese woman.

Here's a bit on the way social support with the protocol worked:
During the initial 6 months, participants attended weekly group intervention meetings that focused on specific behavioral strategies to adopt and maintain the recommended eating and physical activity components. From months 7 to 12, participants were to attend biweekly meetings, with the frequency of these meetings reduced to monthly during months 13 to 18, and these meetings no longer offered during months 19 to 24. The group intervention meetings were complemented with brief individualized telephone contacts between months 7 and 24. The frequency of these telephone contacts was biweekly during months 7 to 12, monthly during months 13 to 18, and biweekly during months 19 to 24. Phone calls were scheduled for a period of up to 10 min; however, the weight loss counselor could extend the call beyond the 10 min period if deemed necessary. All calls followed a structured script, and calls were prescheduled to facilitate the ability of the subject to participate in this call
Here's some of the main findings correlating effect of this contact with results:

Telephone contact time, expressed as the percentage of telephone calls completed, was significantly greater (P G 0.001) using the Q5%, Q7%, and Q10% weight loss criteria, in the MAINTAIN group (79.4%, 79.5%, and 83.6%, respectively) compared with the NONMAINTAIN (69.3%, 70.6%, and 68.4%, respectively) and NONADOPT (64.4%, 67.7%, and 69.6%, respectively) groups. There was no significant difference in participant session attendance between groups for any of the weight loss criteria
In other words, whether folks went to meetings or not wasn't the big factor; the time of direct contact that folks made seems to correlate with success.  My humble take is that, gosh, this is a pretty significant component to ongoing success. So heere's a conclusion, given that, i don't quite understand. The authors state:
On the basis of the results of this study, physical activity was a key factor in the ability to achieve this magnitude of weight loss when used in combination with improved eating behaviors and sufficient contact with the intervention staff (Table 4). Thus, innovative strategies that would promote the adoption and maintenance of sufficient doses of physical activity are needed, and this may facilitate the achievement of larger magnitudes of longterm weight loss.
If "sufficient contact" and "improved eating behaviours" are key, why do the authors only want to propose only workout strategies? Not to worry, though: the authors seem to come around by the conclusion of the study:
In addition, data from the current study indicate that sufficient levels of physical activity in combination with appropriate eating behaviors and maintaining contact with a weight loss specialist are important predictors of Q10% weight loss at 24 months, which is the level of weight loss recommended by the National Heart, Lung, and Blood Institute (14). Therefore, to assist overweight and obese individuals in achieving and maintaining weight losses Q10% of initial body weight, innovative strategies that would enhance long-term adherence to appropriate exercise and eating behaviors and that facilitate continued contact with a weight loss specialist should be implemented.

This is a pretty substantial result that is intriguingly reiterated in a smaller cohort study carried out over at Precision Nutrition awhile ago (and discussed at b2d here).

To the folks who were "extremely happy" with the progress towards their weight goals, 77% said that they'd had regular mentorship from someone who was in the shape they wanted to achieve.

It's important to note that not everyone needs social/expert support to achieve their weight loss goals. Brad Pillon, whose work is continually interesting and intriguing, blogged recently about how happy he was to carve his own path. And any guy who can fast regularly twice a week is probably just that kinda guy. But let's face it: Mr. Pillon of the terrific Eat, Stop, Eat has a heck of a background in nutrition and supplements, so perhaps he's not the Norm in the distribution here? Maybe?

The Four-Day Win: End Your Diet War and Achieve Thinner PeaceMartha Beck of the Four Day Win (your way to Thinner Peace [i love that]) reiterates the value of social support for success in body comp goals, encouraging folks who don't have it for free in their social network to go pay for it (precision nutriton - the forum - is the biggie i've praised for ages for this value; the lean eating program takes that to daily, direct contact).

For the rest of us, then, it seems we more than get by, but can thrive with a little help if not just from supportive friends, but from knowledgeable mentors.

And uptake of *that* human support component is, at least in this Never Ending Study, an unsung key predictor of success with caloric reduction and exercise for attainment and maintenance of body comp success.

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PS Please Remember,

Jamie Oliver's food revolution. Please check out the petition for better food in kids'schools.
JO's excellent TED talk on same.

UNICK, J., JAKICIC, J., & MARCUS, B. (2010). Contribution of Behavior Intervention Components to 24-Month Weight Loss Medicine & Science in Sports & Exercise, 42 (4), 745-753 DOI: 10.1249/MSS.0b013e3181bd1a57

1 comment:

Knorman said...


I just found your blog and there's some excellent info here. This article on the dynamics of weight loss is very interesting. There's some data that's new to me. Very good!

Kyle Norman


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