Reason to avoid grains?
 

I've become a clinical trial junky. :P They're almost like soap operas with really hard to follow scripts. Moving on...

This one, A Palaeolithic diet improves glucose tolerance more than a Mediterranean-like diet in individuals with ischaemic heart disease, is highly interesting for many reasons. Rather than using a single control group who is told to eat their "usual" diet, two groups were each assigned to healthy diets (Mediterranean-type and Paleolithic-type). Both groups were told they were on a healthy diet and were not told what the other group was on, presumably controlling for the "placebo effect" and the fact that control groups typically adjust their diets to be the "healthy diet" of the time when enrolled in such trials.

Surprise surprise. Both groups lost weight (even though calories weren't restricted) and belly fat, increased their glucose tolerance and improved their vital stats overall. Both groups naturally decreased their caloric intake over the 12-week period. (Dietary guidelines for each group are at the end of the post.)

The portion I found most interesting was this
The Paleo-type group, which ate no cereals (including rice in this study), lost, on average, 2.7cm (1in) more from their waist over a 12-week period than the Mediterranean-type group. They also lost an average of 1.2kg (2.6lb) more. The researchers concluded, after examining the data, that the differences in weight loss could be correlated to the total calorie consumptions of the two groups (Paleo-like 1,344 on average, Mediterranean-like 1,795 on average).

Obvious problems: The "Paleo" diet proposed differs greatly from other "Paleo" diets that exist. The "Mediterranean" diet given to patients was closer to a generic "healthy diet" than a true "Mediterranean" diet program. The sample size was also far too small to develop scientifically meaningful results.

What the study did do, though, was create an environment that successfully tested the idea that grains impede the burning of fat. Some researchers have suggested that Omega-6 fats-found in high concentrations in grains-contribute to the creation of belly fats while Omega-3 fats-found in high concentrations in green leaves and fruits-contribute to effective metabolism.

The diets...

Mediterranean-type
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based on whole-grain cereals, low-fat dairy products, potatoes, legumes, vegetables, fruits, fatty fish and refined fats rich in monounsaturated fatty acids and alpha-linolenic acid

Paleo-type
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increase their intake of lean meat, fish, fruits and vegetables and to avoid all kinds of dairy products, cereals (including rice), beans, sugar, bakery products, soft drinks and beer. The following items were accepted in limited
amounts for the Palaeolithic group: eggs (one or fewer per day), nuts (preferentially walnuts), potatoes (two or fewer medium-sized per day), rapeseed or olive oil (one or fewer tablespoons per day). The intake of other foods was not restricted and no advice was given with regard to proportions of food categories (e.g. animal vs plant foods).

They are saying that the Paleo types ate less than the Mediterranean types so how does that test the idea that grains impede fat burning?

Plus there seem to be a couple different items that differed that being dairy, legumes, 'whole-grain cereals' were all in the Mediterranean-type diet but not in the Paleo-type.

If you want a really good introduction to the Paleo diet and grains read this. It is long but very informative. http://www.earth360.com/diet_paleodiet_balzer.html

I know we had a thread here not long ago talking about how a study looked at the effect of whole grains on a diet vs refined grains. The results were that belly fat was decreased. Again that was whole grains vs refined but here is an abstract of that study:
http://www.ncbi.nlm.nih.gov/pubmed/18175740

This is also from 2008 but this talks about cereal grains:
http://www.ncbi.nlm.nih.gov/pubmed/1...m&ordinalpos=1
Cereal grains, legumes, and weight management: a comprehensive review of the scientific evidence.

Williams PG, Grafenauer SJ, O'Shea JE.

Smart Foods Centre, School of Health Sciences, University of Wollongong, Wollongong, Australia. [email protected]

There is strong evidence that a diet high in whole grains is associated with lower body mass index, smaller waist circumference, and reduced risk of being overweight; that a diet high in whole grains and legumes can help reduce weight gain; and that significant weight loss is achievable with energy-controlled diets that are high in cereals and legumes. There is weak evidence that high intakes of refined grains may cause small increases in waist circumference in women. There is no evidence that low-carbohydrate diets that restrict cereal intakes offer long-term advantages for sustained weight loss. There is insufficient evidence to make clear conclusions about the protective effect of legumes on weight.

I don't know that this is true. If the two plans were calorie controlled, sure...but there was a difference of 450 cals a day between the two plans. So they did show that eating less results in a greater waist loss, but not anything that had to do with dietary content.

Dairy can't be implicated in impeding fat burning, as it has been shown in many studies to increase metabolism. Legumes can, effectively, be considered grains. Corn, legumes, wheat, rye, rice, barley, etc. All of these things are "grains" (or "cereals" as the researchers called them). So to make a distinction between "grains" and "legumes" would be a bit disingenuous on the researchers' part.

The crux of the study is that, while the decreased calorie intake can account for the significant difference in weight loss it cannot account for the significant difference in waist loss. The Paleo-types lost an average of 1.12cm per kg, while the Mediterranean-types lost .76cm per kg, about 50% more belly fat.

It would have been helpful to see an examination of overall measurements. It's possible that the Mediterranean-types lost more in other areas (thighs, hips, arms, etc.) while the Paleo-types lost belly fat. However, this could be countered by the body fat percentages. The Paleo-types lost .52% body fat per kg lost, while the Mediterranean-types lost .42% per kg. Those on the "no-grain" diets, overall, just lost more fat than those who included whole-grains.

The other interesting aspect if, of course, that the Paleo-types willingly limited their calorie consumption. The typical argument is that, on a grain-free diet, people will overeat other foods. However, the Paleo-types ate significantly fewer calories than the Mediterranean types, with no researcher suggestion to do so.

Despite the lower-yet-unrestricted calorie consumption, the Paleo-types consumed almost twice the weight of fruit as the Mediterranean-types and more than half again as many vegetables. Interestingly, although their caloric consumption was 30% less than the Mediterranean-types, the Paleo-types only consumed 5% less food by volume (1311 grams vs 1382 grams).

Altari - The studies that showed that dairy increased metabolism were funded by the dairy industry and have since been refuted so dairy is still part of the equation. The study also says that those on the paleo diet restricted eggs, nuts, potatoes, olive oil. The paleo control group also ate more fruit. Overall, the paleo group also had a higher drop out rate. I would think that there were enough differences between the two diets that you can't signal one factor.

As for willingly lowering calorie intake, that occurs a lot in highly restrictive diets, especially for those that don't know what to eat that is high calorie. If you are eating mostly lean meat & fish, fruits and vegetables and limiting your fat consumption, it isn't unusual to eat a lower calorie diet than someone who isn't limiting their fats and some other higher calorie items.

I just did a quick read-through on that one, because I never trust an abstract.

The point of the study I posted was not that weight-loss is impossible when using whole grains. It was that there is evidence to suggest that it is more efficient when grains are replaced by fruits and vegetables. That evidence warrants consideration, IMO.

Also, it's important to note that the Paleo-types did not take part in a low-carb diet-more than 40% of their energy came from carbs.

Obviously weight loss isn't possible with the inclusion of whole grains, I just think there are too many variables to jump to a conclusion that this study shows that whole grains impede fat loss.

And the Food Pyramid was funded by the Grain Industry. Even the study you previously linked to, which simply examined prior studies without regard to who funded them, admitted that there is no causal evidence for whole grains adding benefit to the human diet, for weight loss or overall health.

They ate more eggs (29 grams vs 19 grams) and nuts (11 grams vs 2 grams), despite it being verbally restricted. They did eat fewer potatoes (51 grams vs 77 grams). Again, olive oil can't be implicated, unless the Olive Growers funded the studies showing the benefits of olive oil.

The most marked difference was in grains (18 grams vs 268 grams), with dairy being a close second (45 grams vs 287 grams). Maybe it was the dairy? Or maybe it was both? However, the simple fact, when looking at the diet, is that those restricting dairy and grains (whether it's one or both) lost significantly more fat than those who did not.

Don't get me wrong. These are definitely important things to consider and I'm quite happy that you're bringing them up. :carrot:

Or maybe it was the increased fruit that led to more fat loss?

I also meant in the restriction of olive oil, it could be that they were eating less fat which could account for less calories.

And I wasn't saying the dairy studies were wrong because they were funded by the dairy industry. They were wrong because they were later shown that the data was skewed and was little more than a marketing campaign.

Or maybe it was replacing food that are currently believes to impede fat loss (those containing Omega-6s, such as grains) with foods that are currently believes to promote it (those containing Omega-3s, such as fruits/veggies, eggs and nuts)?

Probably, but as previously mentioned, if it were simply "calories in/calories out" wouldn't the percentages of fat/waist loss per kg be similar? Instead, the Paleo's lost 25% more fat (in % terms) and 50% more waist (in terms of cms) per kg of gross weight lost. When controlling for calories, the Paleos actually lost less gross weight than they should have (their comparative calorie deficit should have given them a 4.7 kg advantage over the Mediterraneans, while they only had a 1.2kg advantage).

While the Paleos lost less gross weight, calorie for calorie, they seemed to get a better biological bang for their buck.

If nothing else, I think it's abundantly clear there were many, many difference between the two groups, making any black-and-white conclusions unwise.

But I do find all the concepts, both in support of and against your paleo premise, interesting! I'll have to actually read the thing later when I get a chance.

Overall, I think the study shows a variety of things but it is a fairly small study with those of pre-existing conditions and a variety of variables. The types of fat certainly could play in it but out body does need a proper balance of omega 3s and omega 6s. Perhaps they were in closer balance? I wonder what it would've shown if grain fed meat was eliminated? Or if the calories were the same? or if 'grains' weren't so broadly defined.

Perhaps the largest problem with most weight-loss studies is that the participants are given a diet to follow and sent home - and it's assumed that they are following the diet given - and even if everybody is, there's great variability in how closely each will follow the diet - and in what foods they will choose.

There's also a great deal of motivation for participants to falsely report. More so than in many other trials, because of the social bias against dieting. People "forget" to write down that candy bar they know wasn't on their diet...

Because of the difficulties in obesity research, and for personal reasons (I have autoimmune disease), I've been more interested in the studies linking grain consumption (even whole grains) to autoimmune issues and more generically inflammation.

It's still a controversial subject, but I think not so much because the studies' methods and results are disputed, but more because people (even some researchers) want to oversimplify the results - so "a grain-heavy diet is associated with autoimmune disease/inflammation, becomes "grains are bad, and should be avoided or even eliminated from the diet - perhaps (probably) for everyone."

My own experience with grains (which does not speak for anyone but me - and even for myself is subject to significant error in interpretation, because I'm not collecting data in the same way a research study would, and I can never be as biased towards my own experience as a scientist has to be) --

but at any rate my own experience with grains is that I have to restrict and limit them fairly strictly (even in whole-grain form) to lose weight best, control my autoimmune symptoms, and generally feel my best.

I still down't yet know if it's all grains, gluten grains, or wheat specifically, but there is definitely a connection between my weight loss, my autoimmune symptoms, my pain and other fibromyalgia symptoms and just generically feeling my best.

For example, I've finally proven to my own satisfaction, that I have a severe problem with wheat. It was hard to tell for sure, because wheat is hard to avoid (it's a hidden ingredient in many foods). Ironically, the longer I've been without wheat, the worse (and more unmistakeable) the reaction to wheat.

For a while I was limiting myself to one or two servings of wheat per week, and it seemed that worked pretty well in eliminating severe flares of the autoimmune symptoms - especially the skin rashes and respiratory symptoms. Then when I went wheat-free, I started noticing that the longer I went without wheat, the worse and more quickly the reaction to wheat. To the point that now a biteful of a wheaty food, results in a swollen and inflamed rash around my nose (I looked like Rudolph).

It could be an allergy or sensitivity or intolerance to wheat, gluten, or grains in general (a lot has been written about each in regards to autoimmune disease, and even the experts can't agree).

I've been experimenting alot. I do find that I don't lose weight very well, and am hungrier when I include a lot of grains in my diet - even whole grains. Even grains that don't seem to aggravate the autoimmune issues. And I haven't lost any weight since I've begun experimenting with grain foods, but I think the experimenting has helped me understand some of what's going on, and has helped me understand which grains I can include (or seem at this point to be able to include) in my diet.

For example, rice (brown or white) doesn't seem to aggravate my autoimmune symptoms, but I tend to overeat white rice, and to a lesser degree brown rice.

Quinoa doesn't seem to aggravate the autoimmune disease, and doesn't seem to trigger hunger or impede weight loss. Perhaps not coincidentally, quinoa is often considered "the grain that isn't a grain," because while it's eaten like a grain, it is not scientifically classified as a grain.

Sweet corn (very young) doesn't seem to be a problem, but I react to corn used as a grain such as in corn chips (baked as well as fried), though not as dramatically as to wheat.

YadaYadaYada... none of this may be of importance to anyone but me - but my point is just that grains maybe be a problem - perhaps only for some individuals. It's why trial and error is so important, because it doesn't really matter that "most people" may be able to eat grain foods healthfully, if you're one of the people who can't.