Study: Energy Expenditure in Whole vs Processed Foods

Iwishyouwell

I was reading this blog:

http://healtheconfusion.blogspot.com/2012/04/spaniards-and-american-tourists-in.html

In which a tourist in Spain provides anecdotal observations about how thin she perceived the Spanish to be, despite a hefty food culture ( a question commonly asked about certain European nations with rich food cultures). Thinking she'd gain weight after indulging heavily on a vacation, she returns home to find she lost a pound. She does some research on whether the calories in more heavily processed foods are handled significantly differently by the body than whole, less processed foods and finds one study, here:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2897733/

Has anybody read this study? I've never heard of this. I know that various foods are processed by the body differently, hence a variation in energy expenditure, but I' thought the general consensus was that the difference was so minor as to not be considered. This study seems to disagree.

Thoughts?

glasshalffull713

I have not read the study, but I am going to check it out!

I did read "The Science of Skinny" which is a book all about why processed foods make us unhealthy and hold on to weight. I don't remember all the explanations, but it is a fascinating read because the author is a biochemist and goes into actual explanations on the molecular level about how our bodies deal with certain foods/chemicals in our foods. As dry as it sounds, it was actually a really good read!

yarwell

The study is a bit disappointing in that the two meals have different protein contents (20 vs 15 grams per sandwich) so it becomes a comparison of different macro compositions as well as the whole vs processed thing.

They do address this in the text, and maintain that the difference in energy effect is greater than that due to the different protein content.

Doesn't surprise me that two calorie equivalent meals are not biologically equivalent.

Azdak

The study was limited in scope, but seemed well constructed. I had a similar experience in Italy 3 yrs ago. I was there for 2 weeks, during which we ate in restaurants twice a day and I was on a mission to try as many different kinds of gelato as humanly possible. We did some walking, but not that much, as Mrs Azdak walks at the speed of a glacier, and she declared that she was on vacation, and thus was determined to avoid any physical exertion whatsoever.

When I returned, I discovered that I had lost 2 pounds during the vacation, which was a shock. I tried to stick with my Italian food + gelato diet but it didn't work the same back in the US.

So I have wondered about the difference: did I do more casual activity than I thought? Did the lowered stress levels from being on vacation have an effect? Was there that big a difference in the nature of the food?

Keep in mind that, while the percentage differences were large, we're still only talking about an area that comprises only 10% of daily intake. The difference may have been "46%", but that was only about 60 calories. Again, for multiple meals and over time, that is not insignificant but it is not life-altering either. And, again over time, people have a tendency to adjust their lifestyles to adapt to these types of small changes.

The good thing is that these are changes that are healthy whether you are overweight or not, so it's not like you have to change to some radical, unsustainable eating plan.

ninerbuff

Too many variables to reach a conclusion.

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Missfit35

Interesting.

Sarauk2sf

There really is not a basis for conclusion due to the limitations of the study.

Pretty much the same as the one referred to here which indicates the opposite:

http://www.bodyrecomposition.com/research-review/hormonal-responses-to-a-fast-food-meal-compared-with-nutritionally-comparable-meals-of-different-composition-research-review.html

ETA: to be honest, - it would seem best to based it on how you, as an individual, feels and how your energy is impacted (not just DIT) as well as adherence and preference. While I try to be very much science based, I feel that we tend to focus so much on the science we often miss the big picture as well as the individual and behavioral aspects.

Kalikel

It would seem to me that fresh-from-Mother Nature foods would be healthier, but it's just a guess. It just feels right, without the stats and studies. But how many people can grow everything they eat?

Except for eggs and corn, I've never eaten straight-from-God foods on a regular basis, so have zero experience. When I get the opportunity to have freshly-picked fruits and veggies, they're always so good. If taste buds get to vote, mine vote for fresh.

Azdak

There really is not a basis for conclusion due to the limitations of the study.

Pretty much the same as the one referred to here which indicates the opposite:

http://www.bodyrecomposition.com/research-review/hormonal-responses-to-a-fast-food-meal-compared-with-nutritionally-comparable-meals-of-different-composition-research-review.html

ETA: to be honest, - it would seem best to based it on how you, as an individual, feels and how your energy is impacted (not just DIT) as well as adherence and preference. While I try to be very much science based, I feel that we tend to focus so much on the science we often miss the big picture as well as the individual and behavioral aspects.

I'm going out on a bit of a limb here, since I haven't (and am not going to) gone back to analyze each study in strict detail, but, from my quick read of Lyle's commentary, I don't think that study is comparable to the one cited by the OP. If I read it correctly, the study referenced by McDonald compared hormonal response (not caloric) in meals that were basically organic vs non-organic. In the OP study, the differences were more in the actual makeup of the food--e.g. fiber content.

The one thing I like about the OP study is that it provides a tiny bit of empirical support for eating what I would call "quality" food vs lesser quality. Definitive? Absolutely not. And I'm not talking about support for "clean eating" or whatever buzzword is floating around these days. Just commonsense healthy eating habits that don't require a radical restructuring of one's diet, exotic foods, authoritarian eating patterns, etc.

Sarauk2sf

There really is not a basis for conclusion due to the limitations of the study.

Pretty much the same as the one referred to here which indicates the opposite:

http://www.bodyrecomposition.com/research-review/hormonal-responses-to-a-fast-food-meal-compared-with-nutritionally-comparable-meals-of-different-composition-research-review.html

ETA: to be honest, - it would seem best to based it on how you, as an individual, feels and how your energy is impacted (not just DIT) as well as adherence and preference. While I try to be very much science based, I feel that we tend to focus so much on the science we often miss the big picture as well as the individual and behavioral aspects.

I'm going out on a bit of a limb here, since I haven't (and am not going to) gone back to analyze each study in strict detail, but, from my quick read of Lyle's commentary, I don't think that study is comparable to the one cited by the OP. If I read it correctly, the study referenced by McDonald compared hormonal response (not caloric) in meals that were basically organic vs non-organic. In the OP study, the differences were more in the actual makeup of the food--e.g. fiber content.

The one thing I like about the OP study is that it provides a tiny bit of empirical support for eating what I would call "quality" food vs lesser quality. Definitive? Absolutely not. And I'm not talking about support for "clean eating" or whatever buzzword is floating around these days. Just commonsense healthy eating habits that don't require a radical restructuring of one's diet, exotic foods, authoritarian eating patterns, etc.

I was not posting to be a 'rebuttal' as such of the one in the OP (it is not strictly comparable at all) - more that there are a few studies out there that, on the surface are conflicting, but they have too many limitations - for example the one you noted re the make-up of the food.

Absolutely agree with your comment re 'commonsense' eating habits. Its just too hard due to the limitations and variables to 'point the finger' at processed foods as such. I mean, the foods they were comparing were both heavily processed.

ETA:. He does refer to body composition - but that is more of an aside.

WalkingAlong

The study is a bit disappointing in that the two meals have different protein contents (20 vs 15 grams per sandwich) so it becomes a comparison of different macro compositions as well as the whole vs processed thing.

They do address this in the text, and maintain that the difference in energy effect is greater than that due to the different protein content.

Doesn't surprise me that two calorie equivalent meals are not biologically equivalent.

It surprised me a little that the 600 calorie meal seemed to take more calories to burn off than the 800 calorie meal, though. Or maybe I'm reading figure 2 wrong.

In a way, it seems intuitive that this would be the result. One sandwich had a fiber-rich, whole grain bread that included whole sunflower seeds and the other was white bread. I would expect my body to process Wonder bread really easily and whole seeds and grains much less efficiently. I mean, put a slice of each in a bowl of water and watch how quickly each breaks down. Not that that is 100% indicative but just the physical breakdown is part of it.

MaidensAndMonsters

I personally feel much better on whole foods than processed. But, that's just me personally. I think everyone's body works a bit differently and optimal diet will vary a bit from person to person. It's interesting to see the data presented on a whole, but I think personal experience is more valuable.

lindsey1979

I can't say that I'm surprised to read this. I know for me personally I feel SO SO MUCH better when I'm eating whole foods rather than highly processed ones. It's a very dramatic difference for me and one I was wholly unaware of until I cut out the vast majority of highly processed foods and was shocked by how much better I feel. I definitely burn more when I feel better as I'm more active and have more energy.

yarwell

It surprised me a little that the 600 calorie meal seemed to take more calories to burn off than the 800 calorie meal, though. Or maybe I'm reading figure 2 wrong.

The meals were either 600 or 800 calories in both processed and higher protein form. Individual subjects decided whether they were going to compare two 600 cal meals or two 800 cal meals. There were 12 women and 5 men.

Fig 2 shows how it takes more calories to burn off a whole food higher protein meal compared to a lower protein more processed meal of the same calorific value.

Perhaps they should have fed the same meal either whole or liquidized into puree to take out one variable, or made more effort to match the protein content.

Iwishyouwell

You guys rock. Thanks for the conjecture.


Anecdotally it makes sense to me. It lines up with some observations I've made in the past regarding weight loss where I ate a heavily plant and meat based diet, with very little heavily processed foods, and was able to eat more calories, and still lose weight than I'd experienced on a heavily processed diet. But after reading time and again that all calories are pretty much processed the same, I let it go and just assumed my anecdotal evidence was wrong. That never truly felt right, but I did let it go.

Looking forward to further thoughts on this study and more empirical observations.

WalkingAlong

Thanks for clarifying, yarwell. That makes more sense. And I agree-- why not at least make protein equal since we know it has a higher TEF?

I have to admit after seeing figure 2 'my way', I decided to have an Ezekial sprouted whole grain bread sandwich for lunch!

iwishyouwell- I've had that in the past, too, but I can't seem to replicate it-- fast loss with 'produce and lean protein and not much else'.

I also just notice from reading foodie and fitness blogs that an awful lot of people seem to maintain their weight naturally with a lot of nuts and nut butters in their diets. It makes me wonder if there's something about how they're digested so that they are filling but not as 'net calorie heavy' as their gross calories would suggest. I might have to do an experiment, n=1....

SapiensPisces

Following.

Iwishyouwell

I also just notice from reading foodie and fitness blogs that an awful lot of people seem to maintain their weight naturally with a lot of nuts and nut butters in their diets. It makes me wonder if there's something about how they're digested so that they are filling but not as 'net calorie heavy' as their gross calories would suggest. I might have to do an experiment, n=1....

That's interesting, about the nut butters. If you ever do an n=1 I'd very much want to see the results.

WalkingAlong

I don't think I can eat nuts for a week or anything but I'm consciously trying to increase my nut intake, and other plant fats.

This from the study is really amazing:

"Average energy expenditure for the WF meal (137±14.1 kcal, 19.9% of meal energy) was significantly larger than for the PF meal (73.1±10.2 kcal, 10.7% of meal energy)."

So the 'whole foods' sandwich burned up almost 20% of its calories in digestion whereas the 'processed' sandwich burned up 10.7%. Dang. I don't eat a lot of processed foods already but that alone should help me reduce it even more. Being able to eat 10% more food is significant.

lindsey1979

I'm not surprised to see those results. I almost always feel fuller for much longer if I'm eating whole foods as opposed to highly processed foods -- it definitely feels like it takes my body longer to process them. I imagine that is not a coincidence either.

doIdaretoeatapeach

I also just notice from reading foodie and fitness blogs that an awful lot of people seem to maintain their weight naturally with a lot of nuts and nut butters in their diets. It makes me wonder if there's something about how they're digested so that they are filling but not as 'net calorie heavy' as their gross calories would suggest. I might have to do an experiment, n=1....

I've wondered about that myself. I love almost all nuts and could eat them all week (you know, in the name of science.) It always seemed like nut overindulgence didn't make me gain weight the way too much of other high calorie foods does. But I'm still limiting nuts now to keep the calories down.

Are calories in foods still determined the way they were in the dark ages, when I was in school? That is, calories are the amount of heat/energy released when the item is burned? Or is there a more accurate method used now?