Tuesday, August 10, 2010

Nonexercise activities like fidgeting may account for a 1,000 percent difference in body fat gain! NEAT eh?

Some studies become classics in their fields and yet are largely missed by the popular media. This seems to be what happened with a study by Levine and colleagues (1999; full reference and link at the end of this post), which looked at the role that nonexercise activity thermogenesis (NEAT) plays in fat gain suppression. Many thanks go to Lyle McDonald for posting on this.

You have probably seen on the web claims that overeating leads to fat loss, because overeating increases one’s basal metabolic rate. There are also claims that food has a powerful thermic effect, due to the energy needed for digestion, absorption and storage of nutrients; this is also claimed to lead to fat loss. There is some truth to these claims, but the related effects are very small compared with the effects of NEAT.

Ever wonder why there are some folks who seem to eat whatever they want, and never get fat? As it turns out, it may be primarily due to NEAT!

NEAT is associated with fidgeting, maintenance of posture, shifting position, pacing, and other involuntary light physical activities. The main finding of this study was that NEAT accounted for a massive amount of the difference in body fat gain among the participants in the study. The participants were 12 males and 4 females, ranging in age from 25 to 36 years. These healthy and lean participants were fed 1,000 kilocalories per day in excess of their weight-maintenance requirements, for a period of 8 weeks. See figure below; click on it to enlarge.


Fat gain varied more than 10-fold among the participants (or more than 1,000 percent), ranging from a gain of only 0.36 kg (0.79 lbs) to a gain of 4.23 kg (9.33 lbs). As you can see, NEAT explains a lot of the variance in the fat gain variable, which is indicated by the highly statistically significant negative correlation (-0.77). Its effect dwarfs those related to basal metabolic rate and food-induced thermogenesis, neither of which was statistically significant.

How can one use this finding in practice? This research indirectly suggests that moving often throughout the day may have a significant additive long term effect on fat gain suppression. It is reasonable to expect a similar effect on fat loss. And this effect may be stealthy enough to prevent the body from reacting to fat loss by significantly lowering its basal metabolic rate. (Yes, while the increase in basal metabolic rate is trivial in response to overfeeding, the decrease in this rate is nontrivial in response to underfeeding. Essentially the body is much more “concerned” about starving than fattening up.)

The bad news is that it is not easy to mimic the effects of NEAT through voluntary activities. The authors of the study estimated that the maximum increase in NEAT detected in the study (692 kcal/day) would be equivalent to a 15-minute walk every waking hour of every single day! (This other study focuses specifically on fidgeting.) Clearly NEAT has a powerful effect on weight loss, which is not easy to match with voluntary pacing, standing up etc. Moreover, females seem to benefit less from NEAT, because they seem to engage in fewer NEAT-related activities than men. The four lowest NEAT values in the study corresponded to the four female participants.

Nevertheless, if you have a desk job, like I do, you may want to stand up and pace for a few seconds every 30 minutes. You may also want to stand up while you talk on the phone. You may want to shift position from time to time; e.g., sitting at the edge of the chair for a few minutes every hour, without back support. And so on. These actions may take you a bit closer to the lifestyle of our Paleolithic ancestors, who were not sitting down motionless the whole day. Try also eating more like they did and, over a year, the results may be dramatic!

Reference:

James A. Levine, Norman L. Eberhardt, Michael D. Jensen (1999). Role of nonexercise activity thermogenesis in resistance to fat gain in humans. Science, 283(5399), 212-214.

27 comments:

Aaron Blaisdell said...

Very cool find! I guess I've always avoided yoga and meditation because, being a lean fidgeter by nature, I didn't want to loose my metabolic advantage by calming myself down. LOL! I like the fractal nature of fidgiting, pacing, posture changes as well. They are our body's mini levy flights (hat tip to Brent Pottenger). Fits well with a Nassim Taleb approach to life.

GK said...

This study jibes completely with Gary Taubes' GCBC chapter where he talks about luxuskonsumption, i.e. the body's impulse to move when overfed.

But you have to be careful here about assigning cause and effect. Are some people people lean because they move, or do they move because they are lean?

People who are more predisposed to store those extra calories will not have the extra energy available and thus won't unconsciously expend energy.

Brandon said...

I try to stand for at least part of the day while working at the computer. It's much more likely you'll pace around the room a bit while thinking out some complex problem if you are already standing up.

I think more clearly standing, too, but it's more relaxing to sit so I always fight with myself about it.

Ned Kock said...

Hi Aaron.

I guess you are one of the lucky ones!

Ned Kock said...

Hi GK.

Good point, one cannot rule out the possibility that lean people are naturally predisposed to more NEAT.

One interesting thing about this study is that all folks were overfed about the same (1,000 cal above maint.), and yet the variation in fat gain was dramatic.

Ned Kock said...

Hi Brandon.

I guess most people tend to have the same problem; they have to fight the impulse of sitting down too much.

At the risk of stretching the paleo argument too far, perhaps one reason for that is that our Stone Age ancestors had no comfy chairs to sit on.

Sitting on the ground or on logs, squatting etc. practically force you to shift position often. At least that's my guess; although I don't do those things often.

Kindke said...

Im not convinced at all about this NEAT stuff. Atleast as far as physical activity goes becuase we know that physical activity burns of so few calories.

Lets take the person with the largest fat gain (i.e. the fat person )and the least fat gain ( i.e. the lean person), then lets have the fat person copy exactly what the lean person does and repeat the experiment. Put in this context, how confident would you be of near equal fat gains?, As predicted by the NEAT theory.

No, its all to do with hormones with a little genetics thrown in.

They would of done much better to measure adipokines.

Ned Kock said...

Hi Kindke.

You raise some good points, but consider that a small movement that alone uses up 6 calories will consume 600 calories per day if performed 100 times per day.

Also, it is quite possible that NEAT is associated with hormonal changes. The questions are: Which ones? and To what extent?

NEAT activities are of the type that would rely heavily on fat oxidation while they are being carried out, so I wouldn't expect glucose regulation hormones to be heavily involved.

Michael Barker said...

I get this. The one thing that should be pointed out, that Taube mentions somewhere, is that the extra energy is directed more to muscle tissue. If you aren't set up this way then it would be going more to adipose.

I've always been lean, muscled and a bit hyper. This can be said of all the people of my family with this body type. We are the "glutton" group. The more restrained eaters tend to be heavier.

I don't, however, believe this can be changed. The "pigs' stay thin in my family while the hefty tend to move towards getting softer.

I don't really know at what level this occurs in the body but I feel it as having as like a light coffee buzz, most of the time. Getting up and moving around won't get you here. It has to be in you already.

The weird part is that longevity, at least in my family, correlates better with a higher weight.

Pål Jåbekk said...

A perquisite for conscious use of NEAT to lose weight is that energy expenditure and energy intake are independent factors. Most data don’t support this. Extra movement usually cause compensatory increased hunger and decreased metabolism. This is the likely reason why most people are weight stable most of the time despite large daily variations in energy intake and expenditure. From what I’ve read it seems most likely that the execs NEAT by some are caused by a better metabolism mostly related to a better availability of oxidizable fuels.

If we manipulate fat tissue into increasing lipolysis our metabolism is increased and we feel like moving. A greater effect seems to be achieved if both fat and glycogen stores are sending energy into the system. It’s the opposite (or the same) with hunger. Reducing fat tissue lipolysis or fat oxidation cause increased hunger and decreased metabolism. The effect is even greater if both fat and glycogen breakdown are inhibited. In most animal models studied increased fat storage occur prior to increased hunger. Thus hunger increased because of lack of oxidizable fuels, whether caused by starvation or excess fat storage.
More her:
http://ramblingsofacarnivore.blogspot.com/2009/11/about-hunger.html
and here:
http://ramblingsofacarnivore.blogspot.com/2009/11/local-cellular-hunger.html

Ned Kock said...

I think hunger suppression and voluntary physical activity can happen at the same time.

This usually happens with a change in diet though, which makes it difficult to pinpoint the source of the effect.

Eating higher satiety foods is often involved.

Pål Jåbekk said...

Yes, Ned I think they can happen at the same time. Just trying to illustrate the complex relationship between voluntary behavior and physiological mechanisms. Will, still matters. Even if we are tired and have a low metabolism we can still force ourselves to move and by doing so increase metabolism making us feel more vigorous. But, it is like GK said; its hard to point at cause and effect in this subject.
Still, very interesting study.

Ned Kock said...

I think that the main contribution of this study is contrasting NEAT effects with the effects of: overeating as a means of increasing BMR, and the thermic effect of food.

Several folks are quite realistic about those two latter effects. These tend to be the folks who have looked at the research literature.

Others exaggerate those two effects greatly, and many people believe them.

Ned Kock said...
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Ned Kock said...
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Ned Kock said...

Your comment is very interesting Michael. I wonder if that has anything to do with the increased insulin sensitivity that body fat sometimes induces. You've seen this GH post, but let me add it here for the benefit of stumblers:

http://healthcorrelator.blogspot.com/2010/08/growth-hormone-insulin-resistance-body.html

Ultimately longevity increase is a systemic effect. If one has a high likelihood of living beyond 90, but a particular diet or lifestyle compromises (even if slightly) a single major organ (e.g., kidney, liver), the person may shorten lifespan by several years by adopting that diet or lifestyle.

Well, evolution is not an engineer. Intelligent robots with hardy and exchangeable parts would be practically indestructible. But then again, without the hormones and other interesting things that make us human, we might not care as much about existing as robots.

Christian Wernstedt said...

What do you think of the connection between leptin and NEAT?

I found this study interesting.

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T0P-4GP1VKP-3&_user=10&_coverDate=08%2F07%2F2005&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=df630eebce062fdd401cdbc45750fab9

They injected rodents with leptin and found that it resulted in an increase in NEAT.

If leptin is an important regulator of NEAT, we need to look at what could have impaired leptin signaling in obese people. How about fructose and grain lectins? The latter suggested by research by Staffan Lindeberg.

Ned Kock said...

Hi Christian.

Leptin seems to be getting more and more attention lately; “the master hormone” some call it. But I would expect to see a connection with adiponectin as well, and there is a lot more adiponectin in circulation than leptin. (And with other hormones, even some yet to be discovered.)

I couldn’t get to the link you provided, but got this one (below). Maybe it is the same study.

http://jcem.endojournals.org/cgi/content/abstract/84/8/2751

Leptin decreased appetite as well in the rodents, and increased NEAT as you noted.

Serum leptin tends to go down with body weight, reflecting lower body fat (adiponectin goes up as weight goes down). And in the study with humans discussed in this post, body weight seemed to be uncorrelated with NEAT. So the leptin-NEAT connection seems a bit weak for humans, at least based on this one study.

Btw, I would expect stimulants (e.g., caffeine) to have an effect on NEAT similar to that of leptin.

Kindke said...

I would like to add that anecdotally, I "unconsciously" became more physically active after loosing weight. I even joined a gym and now visit 2 times per week, something which ive always been 'planning' to do for years but for whatever reason didnt.

I'm convinced that NEAT comes before the cause and effect of over-eating should be considered.

I.E. availability of energy within the body causes NEAT, and not excess dietary calories.

The topic of over-eating and fat gain is absolutely huge though, there are literally thousands of variables to control for.

I would like to see alot more research on adipokines and adiponectin in particular though.

On the other hand I wish people would give up on Leptin, it is an anti-starvation hormone, it's only significant when its levels are low, having high Leptin is no different to having "normal" leptin, that is, once leptin crosses the normal threshold, increased levels dont do anything.

Byron said...

Interesting stuff, Ned. Thanks.
In my experience I move a lot more if I´m leaner. And vice versa. Also intersting to think about the anorexia nervosa people who usually have a huge urge to move although in starvation mode. But other comments were also very right in regard of hormones. If my thyroid gots crazy (hashimoto) there is absolut no chance to command "move" or in hyper times "stop". Greetings.

Christian Wernstedt said...

Hi Ned,

Thanks for your feedback. Here is the rodent study that I looked at. This link should work better:

http://www.ncbi.nlm.nih.gov/pubmed/16039677

PS. Great blog, BTW.

Ned Kock said...

Hi Kindke and Byron, thanks.

It seems that in your case, a decrease in circulating leptin (and possibly an increase in leptin sensitivity) is associated with more NEAT.

Weight loss is associated with decreased circulating leptin:

http://www.nature.com/nature/journal/v395/n6704/abs/395763a0.html

Ned Kock said...

Thanks Christian.

Jack C said...

Ned,

A simple explanation of the phenomenon you describe is given in the study "Physical inactivity amplifies the sensitivity of skeletal muscle to the lipid-induced downregulation of lipoprotein lipase activity"

http://www.ncbi.nlm.nih.gov/pubmed/16195388

Ned Kock said...

Nice find Jack, thanks. A reduction of 90 percent!

Jack C said...

Ned, My computer was balky last night and did not let me complete my post.

Physical inactivity has a powerful effect on suppressing lipoprotein lipase (LPL) activity in skeletal muscle, the rate limiting enzyme for hydrolysis of triglyceride (TG) rich lipoproteins. This, I believe, is a mechanism of self protection to prevent excess free fatty acids that result from TG metabolism from entering the bloodstream.

The result of reduced LPL activity is a sharp drop in TG metabolism which causes a sharp increase in serum TG and increased inflammation.

Increased inflammation results in a decrease in LPL synthesis by the liver which further decreases TG metabolism.

Inflammation also causes increased synthesis of endothelial lipase (EL) by endothelial cells. The preferred substrate of EL is HDL, so serum HDL levels are decreased by increased catabolism by EL.

LDL density pattern was found to be the most accurate lipid indicator of angiographically determined coronary artery disease (CAD). The next most accurate lipid indicator was found to be the ratio TG/HDL-C.

Physcial inactivity increase TG, decreases HDL, and therefore increases ratio of TG/HDL which indictes increase in mass of small dense LDL particles and hence increased risk of CAD, diabetes and obesity.

Apparently, it only takes standing and low grade movements to prevent the complete shutdown of LPL activity and provide marked protection against CAD.

Roxie said...

Hi Ned
I thought I'd let you know something interesting that I experienced:

When I took up violin lessons a few years back, I was not on a diet and my lifestyle was generally the same as it had been for most of my adult life. However during the first month, I lost a few kgs. I remember mentioning this to my violin teacher and we simply smiled and let it go. I did not continue with violin and so I wouldn't know whether I would have lost more, but the correlation is there. I did not make any other changes to my life other than practice standing up about 2 hrs a day, and sometimes a little more. I lost a couple of kgs without really trying.

I also recall another conversation with a piano teacher when I was in my early 20s about how hot and tiring the practice was (I used to practice about 4 hrs every day) and she said "of course, it's a workout". So there you have it.
Roxie