Monday, January 23, 2012

All diets succeed at first, and eventually fail

It is not very hard to find studies supporting one diet or another. Gardner and colleagues, for example, conducted a study in which the Atkins diet came out on top when compared with the Zone, Ornish, and LEARN diets (). In Dansinger and colleagues’ study (), on the other hand, following the Atkins diet led to relatively poor results compared with the Ornish, Weight Watchers, and Zone diets.

Often the diets compared have different macronutrient ratios, which end up becoming the focus of the comparison. Many consider Sacks and colleagues’ conclusion, based on yet another diet comparison study (), to be the most consistent with the body of evidence as a whole: “Reduced-calorie diets result in clinically meaningful weight loss regardless of which macronutrients they emphasize”.

I think there is a different conclusion that is even more consistent with the body of evidence out there. This conclusion is highlighted by the findings of almost all diet studies where participants were followed for more than 1 year. But the relevant findings are typically buried in the papers that summarize the studies, and are almost never mentioned in the abstracts. Take for example the study by Toubro and Astrup (); Figure 3 below is used by the authors to highlight the study’s main reported finding: “Ad lib, low fat, high carbohydrate diet was superior to fixed energy intake for maintaining weight after a major weight loss”.


But what does the figure above really tell us? It tells us, quite simply, that both diets succeeded at first, and then eventually failed. One failed slightly less miserably than the other, in this study. The percentage of subjects that maintained a weight loss above 25 kg (about 55 lbs) approached zero after 12 months, in both diets. This leads us to the conclusion below, which is always missing in diet studies even when the evidence is staring back at us. This is arguably the conclusion that is the most consistent with the body of evidence out there.

All diets succeed at first, and eventually fail.

In using the terms “succeed” and “fail” I am referring to the diets’ effects on the majority of the participants. This is in fact better demonstrated by the figure below, from the same study by Toubro and Astrup; it is labeled as Figure 2 there. Most of the participants at a certain weight, lose a lot of weight within a period of 1 year or so, and after 2 years (see the two points at the far right) are at the same original weight again. What is the average time to regain back the weight? From what I’ve seen in the literature, all the weight and some tends to be regained after 2-3 years.


The regained weight is not at all lean body mass. It is primarily, if not entirely, body fat. In fact, many studies suggest that those who diet tend to have a higher percentage of body fat when they regain their original weight; proportionally to how fast they regain the weight lost. Since the extra body fat tends to cause additional problems, which are compounded by the dieting process’ toll on the body, those dieters would have been slightly better off not having dieted in the first place.

Guyenet and Schwartz have recently authored an article that summarizes quite nicely what tends to happen with both obese and lean dieters (). Take a look at Figure 2 of the article below. The obese need to lose body fat to improve health markers, and avoid a number of downstream complications, such as type 2 diabetes and cancer (). Yet, with very few exceptions, the obese (and even the overweight) remain obese (or overweight) after dieting; regardless of the diet.


So what about those exceptions, what do they do to lose significant amounts of body fat and keep it off? Well, I rarely use myself as an example for anything in this blog, but this is something with which I unfortunately/fortunately have personal experience. I was obese, lost about 60 lbs of weight, and kept it off for quite a while already (). Like most of the formerly obese, I can very easily gain body fat back.

But I don’t seem to be gaining back the formerly lost body fat, and the reason is consistent with some of the studies based on data from the National Weight Control Registry, which stores information about adults who lost 30 lbs or more of weight and kept it off for at least 1 year (). I systematically measure my weight, body fat percentage, and a number of other variables; probably even more than the average National Weight Control Registry member. Based on those measurements, I try to understand how my body responds in the short and long term to stimuli such as different exercise, types of food, calorie restriction, sleep patterns etc.

And I act accordingly to keep any body fat gain from happening; by, for example, varying calorie intake, increasing exercise intensity, varying the types of food I eat etc. With a few exceptions (e.g., avoiding industrial seed oils), there is no generic formula. Customization based on individual responses and cyclical patterns seems to be a must.

Looking back, it was relatively easy for me to lose all that fat. This is consistent with the studies summarized in this post; all diets that rely on caloric reduction work marvelously at first for most people. The really difficult part is to keep the body fat off. I believe that this is especially true as the initial years go by, and becomes easier after that. This has something to do with initial inertia, which I will discuss soon in a post on metabolic rates and their relationship with overall body mass.

For people living in the wild, I can see one thing working in their favor. And that is not regular starvation; sapiens is too smart for that. It is laziness. Hunger has to reach a certain threshold for people to want to do some work to get their food; this acts as a natural body composition regulator, something that I intend to discuss in one of my next posts. It seems that people almost never become obese in the wild, without access to industrial foods.

As for living in the wild, in spite of the romantic portrayals of it, the experience is not as appealing after you really try it. The book Yanomamo: The Fierce People () is a solid, if not somewhat shocking, reminder of that. I had the opportunity to meet and talk at length with its author, the great anthropologist Nap Chagnon, at one of the Human Behavior and Evolution Society conferences. The man is a real-life Indiana Jones ().

In the formerly obese, the body seems to resort to “guerrilla warfare”, employing all kinds of physiological and psychological mechanisms, some more subtle than others, to make sure that the lost fat is recovered. Why? I have some ideas, which I have discussed indirectly in posts throughout this blog, but I still need to understand the whole process a bit better. My ideas build on the notion of compensatory adaptation ().

You might have heard some very smart people say that you do not need to measure anything to lose body fat and keep it off. Many of those people have never been obese. Those who have been obese often had not cleared the 2-3 year “danger zone” by the time they made those statements.

There are many obese or overweight public figures (TV show hosts, actors, even health bloggers) who embark on a diet and lose a dramatic amount of body fat. They talk and/or write for a year or so about their success, and then either “disappear” or start complaining about health issues. Those health issues are often part of the “guerrilla warfare” I mentioned above.

A few persistent public figures will gain the fat back, in part or fully, and do the process all over again. It makes for interesting drama, and at least keeps those folks in the limelight.

30 comments:

Gretchen said...

I think one reason people regain the weight is that they think when they reach their goal they'll be able to eat like a thin person. That's not the case, alas. You have to "diet" forever if you want to maintain weight loss.

It's very difficult not to eat what your friends are eating. It's also very difficult never to feel quite full.

People start off with a lot of hope and enthusiasm. With time, they lose that momentum, especially if they go through a stressful time in their life.

I had a friend who succeeded in giving up smoking. Then her ex-husband died, and it threw her for a loop, she started smoking again "temporarily," and the tricks that helped her stop the first time didn't work the second time.

Dieting is like that.

Nigel Kinbrum said...

I second what Gretchen wrote. Life-long vigilance is required to maintain weight loss.

Galina L. said...

I think it is a possible advantage of LC diet for people like me - the food I eat now is the food I like,so I agree to eat LC forever. I am lucky not to have a "sweet tooth". As Gretchen said " It's also very difficult never to feel quite full", and it is what I experienced in a past while dieting. Now I eat within a 6 - 8 hours window, and I am quite full but not staffed after each meal, so my regiment doesn't require a heroic effort. I have been following LC diet for more than 4 years without regaining.

It is a little bit scary to read that all diets will fail eventually. I wonder, how many years should pass after a weight loss in order to be more safe from the regain?

Sam Knox said...

Ned,

All of the data that I've seen regarding the long-term (up to 5 years) failure of weight-loss plans have involved calorie-restricted diets.

Do we have any good long-term follow-ups for ad libitum LCHF diets?

Kindke said...

I think this is a testamont to perhaps how little we are consciously in control of our bodies. Dieting requires extreme conscious exertion, which will not last forever.

Those who maintain weight loss do so because they are still monitoring everything they eat. As soon as that stops, fat comes back.

Despite the billions of $$$ poured into obesity research, the only solution for obesity we have thus far is "will power" exerted by the patient. sigh

Lucas Tafur said...

In my opinion, the most problematic part of dieting is restriction. Whichever diet you choose to follow, you are restricting something, which for many people is impossible to maintain.

I am getting more and more convinced that the best dieting plan is intermittent or alternate day fasting. It makes you feel that a. you are not restricting calories, b. you are eating big amounts of food and c. you can eat "whatever you like" without having to count calories.

Ned Kock said...

Good points Gretchen and Nigel.

Ned Kock said...

Hi Galina. Not sure how many years until one is guaranteed success; there is an issue of modified metabolism here (some call it “broken”), which I’m planning on discussing soon. But 2-3 years keeping most of the body fat lost off already makes one a minority, virtually an exception.

Jim said...

Instead of picking an eating plan and hoping that it will lead to calorie balance, it is more effective for weight maintenance to discover where calorie balance is by counting calories and weighing oneself, and then to find the most satisfying way to eat within that strict calorie level, so that one always feels satiated.

Ned Kock said...

Hi Sam. These long-term adherents to the Optimal Diet (actually a variation of it) seemed to be doing fine, but they were certainly not lean:

http://bit.ly/rW065a

Ned Kock said...

Yes Kindke. I hear a lot about the brain controlling fat storage, usually said in the context of more automatic brain mechanisms.

But there are the subconscious thoughts too, and “guerrilla warfare” is played in that realm too.

Most people who embark on a heavy-duty calorie restriction program soon start obsessing about food, dreaming about it. Many become psychotic.

Ned Kock said...

Hi Lucas. Wouldn’t alternate day fasting involve some serious restriction as well, on the days one is not eating?

Ned Kock said...

Hi Jim. This seems very reasonable.

I would also recommend moving toward minimally processed foods as much as possible.

Needless to say, doing only that (avoid processed foods) doesn’t seem to entirely solve the problem.

Steve Parker, M.D. said...

"All diets succeed at first, and eventually fail."

Hi, Ned.

Here's what I'd say: "Most diets succeed at first, and eventually compliance with the diet fails."

Not as succinct, but more accurate, I think. You can see it in all the long-term diet studies, like Shai's DIRECT trial (NEJM 2008). Folks stop following their assigned or chosen diet.

-Steve

J. Stanton said...

It's worth mentioning that "The Fierce People" is a) a portrait of one tribe out of of thousands, and b) controversial enough in its portrayals to have had two full-length feature films made about it.

Portrayals of African hunter-gatherers, such as the Hadza and the various tribes of Bushmen (see Elizabeth Marshall's "The Old Way" and Michael Finkel's The Hadza) paint a quite different picture.

Culture is not the invention of farmers. Hunter-gatherer societies are quite diverse, and it is not possible to paint them all with one broad brush.

Steve Parker: That's an excellent point.

Kindke: "Despite the billions of $$$ poured into obesity research, the only solution for obesity we have thus far is "will power" exerted by the patient."

Any successful diet must minimize the role of willpower: dietary restriction raises cortisol, and cortisol makes us eat more (note: not the only mechanism at work). I've raised this point before, here.

JS

Ned Kock said...

Hi Steve. Yes, and it seems that those who succeed tend to be the ones who are the most methodical in their adherence to a way of eating that leads to an optimal nutrient/calorie balance in the long run.

Your comment reminded me a bit of this essay by Dr. Eades on the adherer’s effect:

http://www.proteinpower.com/drmike/statins/the-adherer-effect/

Here is an academic paper on the topic, also linked in the essay:

http://circ.ahajournals.org/content/119/15/2051.abstract

Of course those whom some would call good adherers would be referred to as obsessive-compulsive by others.

Richard said...

The idea with the Paleo diet (and by this I mean PaNu) is not caloric restriction, which requires will (or won't)-power, but caloric reduction or substitution. Instead of excess carbs on eats more saturated fats. The result is a weight loss that I believe is relatively easy to maintain EXCEPT if the "adherent" begins to seriously increase carb consumption.

For myself, although I have never been obese, I can see extra weight come back on when extra carbs are consumed.

On the other hand, are we looking for the starving-hunter look, or the reasonably-well-fed hunter look? (Which would be more attractive to the opposite sex?)

But isn't obesity itself the cause (or part of the cause) of the problem? It seems to me that the body is re-programmed when that much extra fat is created and stored, and that very fat people end up with different metabolic issues from people who were never very fat.

Ned Kock said...

Hi Richard. I think that the changes in metabolism that we see in the formerly obese, which seem to be very real, are reversible. I’ll have more to say about that topic in a post that should be up soon.

Anonymous said...

After years of yo-yo dieting I was fortunate enough to find low-carb and have maintained a 40-lb weight loss for 10 years now. As you point out, it's not easy and requires constant self-monitoring. What I find even more frustrating is the struggle to find useful information that actually works to help me maintain my weight and deal with health issues resulting from a lifetime of poor nutrition. All those tax dollars that once they're paid out I have no control over going into misguided research! Thank goodness for bloggers like you!

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Asim said...

Maybe the gut flora that is present is signaling for the past food 'experiences'. All of these diets don't take into account the flora, meaning the same bacteria is present in their gut as prior to the diet, the only difference really is their ratios have changed.

Another point to mention about hunter-gatherers is they eat straight off the plants, meaning they are exposed to a much more diverse set of bacteria that will eventually settle in the gut.

Asim said...

Dr. Ayers mentions this aspect.

The following link also mentions how diversity of gut flora is linked to obesity: the more diverse, the less obese one usually is.

http://ecophysio.fieldofscience.com/2011/04/correlation-between-gut-bacteria-and.html

http://www.sciencemag.org/content/332/6025/32

What may complicate he issue further is quite simply the heavy use of antibiotics in the past of individuals.

Lucas Tafur said...

Hi Ned,

I was thinking more on food choices. Actually, an ADF regimen can be modified to include some calories on "fasting" days, say 15-20% calories of the calories needed for maintaining weight. However, I think the fact that virtually any food can be eaten more freely on eating days might make people tolerate (initially, they should be able to adapt) a fasting day. See it like a a kind of "reward day". Works in the same manner as a planned "cheat meal/day", which makes people efforts "pay off". You are not eating one day knowing that the next day, you will be able to eat without restrictions.

If you couple this regimen with weight training, you should expect increased fat loss and minimal muscle loss on fast days, as research has shown.

David Isaak said...

I think it's important to distinguish between outright failure and a modest rebound.

I think when most people approach their target weight (or reach or whiz down past it), they have been focused on nothing but the scale. Fat loss can be fairly rapid; lean body mass gain is slow.

I think someone at what they perceived before as their target weight, who eats enough protein and keeps exercising will find is that:

1) If the diet was low-carb and is loosened, there will be rebound of anywhere from 3 to 7 pounds--glycigen and water and some degree of rehydration;

2) There will be a "creeping weight gain" of 2-4 pounds per year of lean body mass.

The lowest weight I hit was 147 lbs. When I went to a trainer to be hydrostatically weighed, he told me my body fat was in a fine range (12.7% at that time), but that frankly he thought I was underweight and should add more lean mass. I'm now around 160 lbs most days. I'd still like to swap some fat for muscle, but that's a slow process.

I'm never sure how much I believe in Sheldon's somatotypes--whcih you've discussed before--but his rules state:

Ectomorphs lose weight easily, gain weight only with difficulty

Mesomorphs gain and lose weight easily

Endomorphs gain weight easily, and lose it only with difficulty.

This suggests that there will be few if any endomorphs in a diet study; it will be mesos and endos. One could also hypothesize that endos will be overrepresented, because even though mesos can easily become overweight or even obese, they are more likely to do something effective about it without medical assistance or monitoring.

So it might be that the people who lose weight and maintain most of their loss tend to be mesos (although the can expect some creping weight gain if they keep pumping iron!) Those who lose weight but regain all of it soon are endos.

Just a hypothesis--and one that doesn't count on willpower to explain everything.

--------------
PS I also think that prolonged daily calorie restriction makes everything riskier in tersm of weight regain, and think a high-calories dya at least once a week while losing weight is a wise policy.

Donald Kjellberg said...

Perhaps most diets fail. I lost 130 pounds in about 9 months starting June 2010, and have kept it off without any real conflict.

I am actually surprised how easy and fun it really is. The only real challenge is keeping a steady stream of whole foods that minimize modern industrialized food processing.

I don't want to think of myself as an anomaly. In the end, its not really about dieting. Its about our health; how we retain, regain, and maintain it.

David Isaak said...

BTW, I'm a member of the NWCR, largely because I think low-carbers are vastly underepresented--only about 11% of the registry is low-carbers, which some use to infer that low-carb doesn't usually work. (The NCWR questionnaires are so skewed in the direction of the low-fat paradigm as to be hilarious--but I suspect they also put off a lot of low-carbers.)

Most of the study results on long-term weight loss maintenance (>3 years) quote the usual claptrap about the majority of successful losers practicing continued low-fat dieting, portion and calorie control, not skipping breakfast, daily cardio, and yada yada yada. And it's true--that's what MOST people in the NWCR are doing.

But in a couple of studies, Phelan et al decided to see what the differences were between low-carb dieters in the registry and the majority:

http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=ShowDetailView&TermToSearch=17925473&ordinalpos=2&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum

It's worth hunting down the full text.

The bottom lines:

--Low-carb dieters had no more tendency to regain
--Low-carb dieters ate more daily calories (~500 cal/day more)
--Low-carb dieters did not tend to deliberately restrict portions or calories
--Low-carb dieters engaged in less physical activity (~900 cal/week)

...all while maintaining their weight loss.

Exceptionally Brash said...

Wow!, Dr. Parker, now you are speaking like a thin person. I had to scratch my head after reading the A to Z study, why did everyone gain weight later?, and concluded that people just weren't in compliance. Then when I got into the LC maintenance zone I saw firsthand how the plans may be more suboptimal than advertised. The plan was to get almost to goal weight and "slide" into it, gradually increasing carbs and then backing off that if there was weight gain. Trouble is, once many start doing it, you just shoot straight back up. Taking it down to the earlier strictness doesn't help. Most LC authors don't discuss this, and judging by many comments here, just don't believe it. Dr. Calvin Ezrin discusses it, but gives no reason or real solution, other than "don't stop". Others write it off to age or some sort of newly-acquired character disorder or inability to use measuring cups even if they weren't needed before.
Thank you for this post. Maybe now someone will take it seriously. I thought, "Hey, what if the CW researchers are correct? What if LC sucks and people gain it back?" We are absolutely throwing away all this great data by brushing the problem off as non-compliance.

Gabriella Kadar said...

From my experience of listening to patients who are on a 'low carb' diet, they feel "deprived". They look at pastries, cake, junk and can't or won't make the realization that these things are not 'food'. They are energy but not nutrition. So of course, as soon as these people loose a whack of weight, they begin to tentatively indulge in 'life's great pleasures'. At first, nothing happens. So this gives them courage. Eventually and suddenly the pounds begin to pack on again. Much emotional trauma and denial ensues.

So long as anyone thinks that processed junkfood and high sugar desserts and snacks are desirable, the chance that any weight loss effort will result in permanent change is nil.

Anonymous said...

have you looked at jon gabriel's book, the gabriel method?
He has some interesting ideas about how t stress causes obesity and that dieting is such a stress. It's an alternative to the arguments of which type of diet is better than the next. I've tried Atkins a few times over the years and lost less each time. The last time I lost nothing but still had a rebound of weight gain...not what Iwould classify as effective. I often feel that the first time I try any new eating plan it is always more effective than in subsequent tries. Maybe the placebo effect is involved, maybe the body has a memory of previous adaptations.
A long time ago I read something by a doctor who used calorie restriction in only one circumstance - with patients who were too thin. He restricted their intake for a couple of days until they lost a couple of pounds and then they would gain it all back plus a little more. Sound familiar? he would repeat until they were at an ideal weight.In his opinion , a calorie restricted diet was for weight gain! that story has always stuck in my head. Unfortunately, he had no prescription for weight loss.

trina

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