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Long-Term Benefits of Weight-Loss Plans Unclear

December 4, 2014

Weight LossFat PoliticsFat HealthExerciseFat NewsDiet TalkFat Science

Trigger warning: Weight loss research.

Here’s another article to add to the “No shit, Sherlock” file: “Long-term Benefits of Weight-loss Plans Unclear.”

Weight Watchers Before and After

Weight Watchers’ most effective transformation to date.

Long-term benefits unclear? Well, how on earth can you begin to know what benefits, if any, are due to weight loss when researchers consider a weight loss plan “effective” if fat people manage to lose 5% of their starting weight and keep it off for one year? How can you consider weight loss plans effective when researchers only follow dieters for one or two years? You don’t have a clue about any of this because researchers rarely do follow-ups at 5 years, 10 years, 15 years. If they did, you would find that people have gained some, most, all, or more weight back; that they’ve tried other diets in order to lose weight; that those other diets aren’t any more effective than the first diet tried; and that weight loss doesn’t improve health long-term because the weight loss isn’t permanent for the majority of people who diet.

Atkins, South Beach, Weight Watchers, the Zone — millions of Americans attempt to lose weight each year by following one of these commercial diets, but a systematic review found little difference between the four with regard to weight loss and cardiovascular health.

Gee, ya think? Could it be that there’s little difference between these four diets because none of them are sustainable for more than a few weeks or months? Could it be that none of these diets really take into account what bodies actually need, in terms of nutrients, and that every one of them is set up for the mythical “common man,” all of whom are supposed to be exactly alike in terms of size, activity levels, metabolism, and daily caloric requirements? Could it be that every one of these diets is a “one size fits all” and that none of them actually attain this goal?

“Our results suggest that all four diets are modestly efficacious at decreasing weight in the short-term, but that these benefits are not sustained long-term,” Atallah told MedPage Today.

Atallah said the review focused on the four diet plans because they are followed by so many people in North America and worldwide.

Modestly efficacious in the short term? If the aim of these diets is to reduce the number of fat people, I’d say none of them are anything near modestly efficacious even in the short term. You say that a weight loss of 8 to 13 pounds is what most people achieve on Weight Watchers (the most effective of the four diets). I’m sorry, but a weight loss of 8 to 13 pounds isn’t going to turn most “obese” people into “overweight” people, nor is it going to turn most “overweight” people into “normal-sized” people. These diets might work well for people who only need to lose 10 pounds in order to hit a lower BMI category, but if a fat person needs to lose 20, 40, 60 or more pounds in order to hit a lower BMI category, it’s most likely not going to happen.

By one estimate, people in the U.S. spent more than $66 billion on weight loss in 2013, but the efficacy and health risks and benefits of the most popular commercial diets remain the subject of much speculation.

Do you know why people in the US spent more than $66 billion on weight loss in one year? It’s because most of them are repeat customers of the diet industry. They tried one diet, it didn’t work to keep the lost weight off forever, so they tried another diet, which didn’t work any better than the first one, and they kept on trying diet after diet after diet, and none of them were any more effective at keeping lost weight off forever than any other diet they tried.

In an effort to compare the efficacy of the four diet strategies, Atallah and colleagues conducted a systematic search of MEDLINE, EMBASE, and the Cochrane Library from inception to May of 2014 to identify randomized controlled trials published in English that examined their effects on weight loss and cardiovascular risk.

Their search initially yielded 8,393 potentially relevant trials, and after screening titles and abstracts, 645 were reviewed. Of those trials, just 26 randomized controlled trials met inclusion criteria, and 14 of these had follow-up of less than 12 months.

Less than 8% of the potentially relevant trials were reviewed. Only 4% of that less-than-8% met inclusion criteria, and more than half of those had follow-up of less than 12 months. If you want to know how effective weight loss plans are, long-term, you really need to set up studies that actually follow people long term, and long-term follow-up is not 12 months, it’s 5 years, or 10 years. Good luck finding people who are willing to participate in a weight loss study for that length of time.

Of course, that’s the problem with every study done about weight loss — attrition cuts the number of people who can actually stay the course for 12 months, which should tell you something about the diets themselves. They aren’t effective, they can’t be followed long-term, and they don’t work to keep lost weight off forever.

One of the key messages from the analysis is that better studies are needed to understand the short- and long-term efficacy of the four diets, Atallah said.

“We need more head-to-head trials directly comparing these four diets, and involving a large number of participants and research sites, in order to get the best picture of which diet strategy is best for weight loss,” she said.

She added that there is even less known about the impact of the four diets on key aspects of cardiovascular health, including lipid profile, blood pressure and glycemic control.

Good luck setting up those head-to-head trials with a large number of participants and research sites. People are too diverse (e.g., exercise, smoking, drinking, stress, body composition, amount of sleep, income, housing) to be able to get a large enough sample of people with the same social, economic, mental, emotional, and physical characteristics to compare.

Trying to track changes in the health of the participants isn’t going to be any easier. I don’t think a study can be designed that takes into account all the factors that affect cardiovascular health. Diet is just one of the many factors, and it’s nearly impossible to isolate any changes in health and attribute them solely to any one diet.

“Despite their popularity and important contributions to the multi-million dollar weight loss industry, we still do not know if these diets are effective to help people lose weight and decrease their risk factors for heart disease,” noted senior author Mark J. Eisenberg, MD, MPH, of Jewish General Hospital/McGill University in a press statement.

Weight Watchers Tattoo

Branded Tattoos: Always a terrible, terrible idea.

Isn’t this what it all comes down to, really? “Important contributions to the multi-million dollar weight loss industry” — and it should be $121-billion dollar weight loss industry. It all comes down to how well these diets make money for the people who created them.

What better way to make money hand over fist than to come up with a diet that’s effective for modest (very, very modest) weight loss in the short term, but doesn’t work for maintaining that weight loss in the long term. Keep people convinced that it’s not the fault of the diet, that it’s their fault they can’t maintain that weight loss, and they will keep coming back to that diet (or a different one) in an effort to be “successful,” when they aren’t the ones who need to be “successful,” it’s the diet that needs to be “successful” (good luck with that one — that “successful” diet hasn’t been created yet, and probably never will be).

“With such a small number of trials looking at each diet and their somewhat conflicting results, there is only modest evidence that using these diets is beneficial in the long term,” he said, adding that larger clinical trials with longer follow up times are needed.

Even if you could create larger clinical trials with longer follow-up times, I would be willing to bet that the outcomes would be the same — there would be very little evidence that using any of those diets is beneficial in the long term.


3 Comments leave one →
  1. December 5, 2014 9:24 am

    While I agree about the crappiness of the research, the number of studies returned by a search of the literature is irrelevant. If you’re trying to make sure you don’t miss anything, you conduct a ‘broad’ search – this means you get a lot of stuff that is actually not relevant. It is not an indicator of anything other than the thoroughness of the search itself. It is quite normal to do a broad search and eliminate the vast majority of the hits you get just by looking at the title, many more by looking at the abstract, and, hopefully, only needing to review a small number of papers in full to see if they match what you’re looking for.

    Also, the people in the study do not need to be identical in all aspects. As you say, that would be impossible. Increasing the number of people in the study reduces the risk of systematic uneveness, and best practice would have you ASK about things that might confound the results – smoking, diet history, family disease history, socioeconomic status, lifestyle factors. A lot of studies fall down on taking into account well-known confounds such as fitness level; almost none ask about dieting history – and as a result the link between dieting history and outcome is unclear; and it is practically impossible to control for the effects of weight stigma, which also increases as BMI goes up, and, like other forms of prejudice, acts as a chronic stressor, which has been linked to poorer cardiovascular outcomes.

    It is this inability or unwillingness to control for confounds and the lack of decent follow up that are the problem, not anything to do with the number of studies returned in the searches or the dissimilarities between participants per se.

  2. coupondude permalink
    December 8, 2014 3:44 am

    (As a notice, my reply references diet and eating disorders, so just a heads up because I know what it’s like to have triggers)

    I’ve witnessed a loved one’s weight yo-yo many times as a result of various diet programs over the decades, and unfortunately it didn’t do their physical health, metabolism, mental well being or self confidence any favors 😦

    The only program that I’ve seen that had any long term positive effect for them was when they started weight watchers, but NOT because as a diet plan it is any good. To say that I’m not a fan of diets at this point would be an understatement, but I digress … They encouraged physical activity which is all fine and well, and the program encouraged people to “eat back” the calories they burned through exercise, so that it didn’t add to the deficit that already existed in their daily point allotment. That is fine on paper, but of course anyone who has ever dieted knows that isn’t what most people will actually do. Instead, any dieter knows we use exercise to further increase the caloric deficit on top of our already (and ever) restricted eating. In any event, the place where they went each week was a few store fronts down from the local gym, so it made exercising convenient.

    The second thing is that by virtue of its points system, it moved them toward eating more natural foods, vegetables and fruits in place of processed foods and snacks. This is because many of the former were assigned lower point values than their latter counterparts. Of course WW doesn’t mind if you eat prepackaged/processed food
    stuffs, provided it’s from their own rather expensive product line, but since they could neither afford nor justify such high prices, they sought out ways to create
    meals/snacks at a lower price and without the the fun chemicals you find in more processed foods.

    Please Note: I intentionally try to stay away from framing food in terms like “good or bad” or “healthy or unhealthy” (working through my own demons) but I think it’s reasonable to suggest foods you prepare yourself are preferable than highly processed ones, when time and money permits of course.

    Now having said that, I know from talking with them that weight watchers can also be very demoralizing with its weekly weigh-ins, made even worse by how those who have lost the most weight receive the biggest applause. For starters, this creates a competitive environment where you (and thus your sense of self worth, esteem, etc) are measured against others, by who dropped the biggest number on a damn scale. I doubt I need to elaborate on why that’s a bad thing. This also puts people under tremendous pressure (external and/or internal) to want to always lose lose lose each week. Otherwise, they carry with them a sense of dejection or failure for the next 7 days week (until the next weigh in) if their number didn’t drop and/or drop enough. So you’re introducing stress and depression, on top of the various stressors and other effects from severe prolonged caloric deficits, and which come with their own bundle of deleterious effects.

    The thing is that those changes that were positive, ie engaging in movement one enjoys, exploring other foods, and becoming more aware of nutrition, aren’t anything that a HAES approach wouldn’t also have given them. An approach that would have come without the damaging physical, emotional and mental health affects from repeated dieting and weight fluctuation.

    I just wish they (and I as well) had even known about such a concept a long time ago, so that one at least had a chance to consider it. Of course, HAES isn’t something that can be monetized, packaged, and sold as a product to make anyone rich, so it will always face an uphill battle just for recognition. The only reason I even know it exists is because in the process of trying to recover from my own ED, I came across people talking about it on the internet.

  3. Michele permalink
    December 11, 2014 10:09 am

    I believe that the basic rules of keeping shape are the same for everyone. Though, everyone should adapt them for himself. For me fitness is the best way. When I stop going to the gym I immediately gain weight (unless I starve myself). For me all the diets are very depressive, I can not live without sweets and cookies, that’s why I choose fitness. Regular training is very rewarding: I’ve noticed my first results within 1 month, and it was an awesome stimulation for future trainings. When I feel tired I take Super Army Formula by Military Grade and it quickly restores my strength and enthusiasm. It provides the necessary nutritional supply, which is vital when you are training intensively. Thus, nothing prevents me from eating occasional cookie or a bar of chocolate when I want it so much.

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