Study Shows Why It’s Hard to Keep Weight Off : Pre-Maintenance & Maintenance Forum : Active Low-Carber Forums

#1 ^

Thu, Oct-27-11, 12:18

Demi

Strong Girls Rock!

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Are You Hormonally Destined to Regain? Don't Believe It!

Quote:

From The New York Times
October 26, 2011

Study Shows Why It’s Hard to Keep Weight Off

Gina Kolata

For years, studies of obesity have found that soon after fat people lost weight, their metabolism slowed and they experienced hormonal changes that increased their appetites. Scientists hypothesized that these biological changes could explain why most obese dieters quickly gained back much of what they had so painfully lost.

But now a group of Australian researchers have taken those investigations a step further to see if the changes persist over a longer time frame. They recruited healthy people who were either overweight or obese and put them on a highly restricted diet that led them to lose at least 10 percent of their body weight. They then kept them on a diet to maintain that weight loss. A year later, the researchers found that the participants’ metabolism and hormone levels had not returned to the levels before the study started.

The study, being published Thursday in The New England Journal of Medicine, is small and far from perfect, but confirms their convictions about why it is so hard to lose weight and keep it off, say obesity researchers who were not involved the study.

They cautioned that the study had only 50 subjects, and 16 of them quit or did not lose the required 10 percent of body weight. And while the hormones studied have a logical connection with weight gain, the researchers did not show that the hormones were causing the subjects to gain back their weight.

Nonetheless, said Dr. Rudolph Leibel, an obesity researcher at Columbia, while it is no surprise that hormone levels changed shortly after the participants lost weight, “what is impressive is that these changes don’t go away.”

Dr. Stephen Bloom, an obesity researcher at Hammersmith Hospital in London, said the study needed to be repeated under more rigorous conditions, but added, “It is showing something I believe in deeply — it is very hard to lose weight.” And the reason, he said, is that “your hormones work against you.”

In the study, Joseph Proietto and his colleagues at the University of Melbourne recruited people who weighed an average of 209 pounds. At the start of the study, his team measured the participants’ hormone levels and assessed their hunger and appetites after they ate a boiled egg, toast, margarine, orange juice and crackers for breakfast. The dieters then spent 10 weeks on a very low calorie regimen of 500 to 550 calories a day intended to makes them lose 10 percent of their body weight. In fact, their weight loss averaged 14 percent, or 29 pounds. As expected, their hormone levels changed in a way that increased their appetites, and indeed they were hungrier than when they started the study.

They were then given diets intended to maintain their weight loss. A year after the subjects had lost the weight, the researchers repeated their measurements. The subjects were gaining the weight back despite the maintenance diet — on average, gaining back half of what they had lost — and the hormone levels offered a possible explanation.

One hormone, leptin, which tells the brain how much body fat is present, fell by two-thirds immediately after the subjects lost weight. When leptin falls, appetite increases and metabolism slows. A year after the weight loss diet, leptin levels were still one-third lower than they were at the start of the study, and leptin levels increased as subjects regained their weight.

Other hormones that stimulate hunger, in particular ghrelin, whose levels increased, and peptide YY, whose levels decreased, were also changed a year later in a way that made the subjects’ appetites stronger than at the start of the study.

The results show, once again, Dr. Leibel said, that losing weight “is not a neutral event,” and that it is no accident that more than 90 percent of people who lose a lot of weight gain it back. “You are putting your body into a circumstance it will resist,” he said. “You are, in a sense, more metabolically normal when you are at a higher body weight.”

A solution might be to restore hormones to normal levels by giving drugs after dieters lose weight. But it is also possible, said Dr. Jules Hirsch of Rockefeller University, that researchers just do not know enough about obesity to prescribe solutions.

One thing is clear, he said: “A vast effort to persuade the public to change its habits just hasn’t prevented or cured obesity.”

“We need more knowledge,” Dr. Hirsch said. “Condemning the public for their uncontrollable hedonism and the food industry for its inequities just doesn’t seem to be turning the tide.”

http://www.nytimes.com/2011/10/27/h...tudy-finds.html

Unfortunately, I can't find any mention of the actual diets that were given to the participants to maintain their weight loss. However, if it was based on what they were given in the first place in order to measure their hormone levels and assess their hunger and appetites, then I'm not at all surprised at the results.

Although, as we all know, it is hard work maintaining weight loss, I'm sure the results would have been far more favourable if a low carb woe had been used for maintenance purposes.

Last edited by Demi : Thu, Oct-27-11 at 14:00.

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#2 ^

Thu, Oct-27-11, 13:49

Demi

Strong Girls Rock!

Posts: 26,731

Plan: Muscle Centric
Stats: 238/153/160 Female 5'10"

BF:
Progress: 109%

Location: UK

... and here's Dr Barbara Berkeley's take on this study:

Quote:

October 27, 2011

Are You Hormonally Destined to Regain? Don't Believe It!

by Barbara Berkeley, MD

The longer I hang around the weight loss field, the more I am impressed by successful weight maintainers. Obviously, I have a major interest in the factors that contribute to permanent weight stabilization...since I've devoted a book and a blog to them. Over the past 10 years, the number of people who have figured out maintenance seems to have grown. Perhaps this is just because we can speak to one another more readily via the internet. Or maybe it's because there actually are alot more of us. Whatever the reason, I have worked with, met, and corresponded with so very many of you....people who have made true, permanent change. None of you believes it to be impossible (though many of you would say that the job is a tough one). Certainly none of you thinks that returning to obesity is an unavoidable destiny.

Apart from the greater visibility of successful maintainers, another thing that's new in recent years is the 24 hour news cycle. The need for constant headlines has created a news machinery that snatches up any juicy tidbit and gives it front page placement for as long as a buzz lasts. A great source for controversial and sensational news is the stream of endless medical studies that are performed worldwide. Everyday brings yet another pronouncement, another result. Many results contradict one another, leaving the non-scientists among us in utter bewilderment.

Scientific studies are not meant to be looked at in isolation nor are they meant to be accepted at face value. Instead, studies are meant to add to an accumulating body of evidence. Once the evidence is strong enough on one side, we can make better conclusions about validity. Studies also should be read critically and their weaknesses should be evaluated and discussed. But the media's reporting of individual study data gives equal weight to each report and provides no critical review. And because these studies appear in print and on the major television networks, they are taken as gospel by many people. That’s a disservice to most of us.

This brings me to the study published today in the New England Journal of Medicine about hormonal changes after weight loss. As soon as this study was released, the results were picked up by all the major news outlets. In anticipation of reaction to the story, I started posting to Facebook and Twitter early this morning. As I expected, I began receiving emails from patients and those who follow my blog as soon as the media released the study results. Numerous questions arose in our office practice just this morning. But this "story" is actually just a single study and what this study says is uncertain at best.

Here's the way Fox News covered this story.

Let’s look at the first two paragraphs of their article:

The findings of a new study suggest that dieters who have regained weight are not just slipping back into old habits, but are struggling against a persistent biological urge – their hormones.

"People who regain weight should not be harsh on themselves, as eating is our most basic instinct," Joseph Proietto of the University of Melbourne in Australia, an author of the study, said in an email. The research appears in Thursday's issue of the New England Journal of Medicine.

In other words: We’ve discovered that you’re pretty much biologically destined to regain your weight. It’s you against biology and you know how that’s going to go! So don’t be “harsh” on yourself!!

But let’s look at what this study actually did:

A group of scientists in Australia took 50 obese people and put them on a weight loss diet for 10 weeks. At the beginning an end of the diet they measured various hormones that are associated with appetite and the impetus to eat. They then asked these patients to maintain their weight loss for one year. At the end of that year, they again measured hormones and concluded that most of the hormones were still changed by the experience of dieting. The changes were such that they would encourage regain of weight. Researchers also reported that the maintainers had greater appetite than they did before their diet and thus would have to struggle more with self control.

Next let’s take a more critical look at the study:

The biggest red flag for me is the way weight loss was accomplished. The subjects in the study were given a diet of just 500-550 calories/day for 10 weeks. This was done through the use of OPTIFAST as a liquid diet (along with some vegetables). (By the way, I’m capitalizing the name because that is the way the manufacturer requests it be written).

Back in 1987, I was privileged to be recruited as medical director of a hospital weight management program in Cleveland. The program had been developed by one of the two physicians who invented OPTIFAST. It was the first program to pioneer its use. I learned a lot. While I still use OPTIFAST in my weight management practice today, I would never return to the way we used it then.

In those days, we treated patients with a 400 calorie liquid diet consisting solely of the liquid supplement. It worked great….during the weight loss phase. But once the patient had lost weight, the deprivation of a full liquid diet and the low calorie count increased cravings and hunger. Patients regained. This happened to many people, most famously Oprah Winfrey, who dragged a wagon full of fake fat onto her stage after losing about 50 pounds and then put it all back on in public view.

After some years, OPTIFAST redesigned its product to increase the daily calories to 800. In my own practice, I have taken its use a step further to ensure good maintenance. We use OPTIFAST to substitute for 2 meals and a snack and have patients eat a healthy Primarian meal at either dinner or lunch. This gives us the best of both worlds: excellent calorie control, good levels of protein with low levels of carbohydrate and many weeks or months for the patient to “practice” the type of eating that will be the pillar of their maintenance. Our patients typically consume between 1000 and 1200 calories per day and get excellent, predictable weight loss while reporting good appetite suppression.

So what can be said for the hormonal values measured after a starvation diet of just 500 calories per day? For 10 weeks? I’m not sure that much can be made of them at all.

Here’s a second problem. Study maintainers were not asked to eat a specific meal plan. While it was suggested they eat low fat and low glycemic index foods, this was not monitored. So there is no examination of whether the type of foods maintainers consume effect the hormones they create.

Finally, the successful maintainers I know work very hard at keeping weight off. While some of them do complain of hunger, a large number do not. Once again, I believe that the choice of foods after weight loss is the key…an effect not examined here.

So here’s my message: don’t be discouraged by studies you see in the media and don’t give them extra weight simply because they are featured on Good Morning America or CNN. Continue to work on the plan that fits you best, which should hopefully be some form of ancient diet. And always believe in the evidence of your own eyes and experience.

http://refusetoregain.com/refusetor...believe-it.html

Quote:

Originally Posted by Dr Barbara Berkeley

Finally, the successful maintainers I know work very hard at keeping weight off. While some of them do complain of hunger, a large number do not. Once again, I believe that the choice of foods after weight loss is the key…an effect not examined here.

My thoughts exactly!