Matt Metzgar

Inflammation and Insulin Resistance

As far as looking at the ultimate cause of obesity, I used to lean more towards insulin resistance.  Now after learning more over time, I am much more convinced the core problem is inflammation.  There are a few reasons for this.

First, you can find a number of studies with subjects who are overweight but not insulin resistant, even for children.  You can even find studies of subjects who are obese and have low fasting insulin levels.

Second, you can look at the general failure of the low-carb diet to influence outcomes in the long run.  You can cut carbs and this will reduce insulin levels.  It may also reduce inflammation levels, but the effect may be temporary.  There are still zero studies showing that low-carb is effective for weight loss in the long-run (18 months or more).

Third, the simpler theory of inflammation being behind weight gain explains more.  For example, a study last year showed that chemicals in plastics led to weight gain in children.  Though they referred to this as "endocrine disrupters", you could just as easy say that these toxic chemicals led to inflammation.

Fourth, you can look at studies linking food allergy and weight gain.  In the opposite way, if people avoid food they are allergic to, they lose weight.  I've written about this before.

Fifth, you can look at the growing connection between asthma and obesity.  Asthma is an inflammatory response, which not surprisingly links to weight gain.  This study links elevated CRP levels to both asthma and obesity.

I also believe that one of the main regulators of inflammation is the gut flora.  Balancing the gut bacteria seems like the most logical place to start in reducing inflammation.

The Optimal Diet

I have seen a few references to "The Optimal Diet" by Jan Kwasniewski.  The idea is that there is an optimal ratio of carbohydrates, protein, and fat.  The diet claims to improve a number of health problems.  It is mostly a high-fat regimen, with low amounts of protein and carbohydrate. 

If you take a look at the website, there are some suspicious statements in my view.  Here is one:

"Fasting causes apathy, the lowering of the perception of morality, the lowering of mental abilities, asocial and egoistical behaviour. The dropping of the fast produces an improvement in mental numbness."

Now, I know that the Optimal Diet is translated into English, but what does all this mean?  It's nonsense.  There a number of other unsupported or questionable statements on the website.  All this seems to be a prime example of hypnotic writing, where the author tries to write in a very confident tone.

As far as studies that analyze the Optimal Diet, I found only one.  This study tracked participants who followed the Optimal Diet for a number of years.  I acquired the full-text and read through the results. 

The good news is that the diet produced low levels of triglycerides and insulin.  This is expected with the very low carb consumption and lower protein consumption.  Dietary fat produces a minimal insulin response, so you would expect insulin to be low.

On the other side of the coin, total cholesterol was an average of 278.  Some wouldn't view this as a problem, but I would. 

Another item of interest is the BMI (Body Mass Index).  Instead of measuring body fat, this study tracked BMI.  We know BMI is a flawed measure because it doesn't take into account body composition.  A person could have more muscle and the BMI would show them to be overweight.  Nevertheless, it is a general measure of body size.

The average BMI for participants was 24.7.  BMI of 25 or greater is considered overweight.  So it looks like the participants in this study were close to being overweight.  Also, the average age of participants is 51, so I really don't think these people have added muscle mass which is raising their BMI.  I would love to see pictures of these subjects.

Overall, I don't see how this diet is "optimal" in any way.  The basic theory of optimal ratios seems unsupported by science.  Empirical evidence shows some positive outcomes and some negative outcomes. 

Empirical evidence for the Paleo Diet is much stronger.  Humans evolved to eat substantial amounts of both plant food and animal food.  Since carbs and therefore plant food is restricted in the Optimal Diet, I don't see how it can be considered a healthy diet in the long run. 

Mineral Absorption

I've seen a few papers that show there are micronutrient deficiencies in people who are overweight/obese.  This paper shows that overweight subjects had zinc deficiencies.  The article recommends zinc supplementation to correct the situation.

I agree with this, but there is more to the story.  Omega-3 fats affect micronutrient absorption.  In this paper, it is shown that there important interactions between omega-3 fats and zinc.  This paper shows that omega-3 fats can affect zinc levels in the brain.

Therefore, while it may be good to supplement with zinc if you are deficient, it may be more important to get sufficient omega-3 fats in your diet first.

Eggs

The Paleo Diet blog had a long post on eggs last week.  Cordain points out that eggs could not be consumed year-round in the Paleolithic era.  Eggs may have been consumed for a few weeks or few months, but they were a seasonal food.

I was starting to lean in this direction on my own volition.  This summer when I had time off, I got in the habit of eating eggs on most days.  After a while, it just didn't feel right.  When the I started back to work in the fall, I dropped the eggs and felt better.

I think if you substitute eggs for meat too often, you miss too much protein.  Eggs are really a high-fat food, and not a high-protein food.  I usually feel better after eating meat than I do after eating eggs.

Man the Fisher: In Practice

  
I have been trying a few things related to the Man the Fisher idea.  The first is iodine.  I eat virtually no salt and also no seafood, so it seemed like a good idea to try some iodine.  I have been supplementing with it for about a month.  I haven't noticed any huge improvements, but there doesn't seem to be any negative side effects.

Next up are the Trace Minerals shown above.  The idea is that there are critical elements that can only be provided by marine foods.  Again, no big improvements but no side effects either.

I look at these two supplements as insurance policies.  If the historical Paleo diet was heavily dependent on marine food, then I'm covered.

Omega-3 Fats and Probiotics II

This study was done with pigs, but I think the same principle will apply to humans.  They tested germ-free piglets with a combination of fatty acids and probiotics.  The combination again acted in a synergistic manner to produce benefits in the digestive tract.  The full-text is available here(pdf).

All this is related to the hygiene hypothesis again.  By adding good bacteria and omega-3 fats back in our diets, we can improve gut health.

Omega-3 Fats and Probiotics

I've been looking at a few papers that show how fatty acids, particularly omega-3 fats, can enhance the action of probiotics.  A nice review of everything is in this paper.

Overall, this shows how two components of the Paleo diet, omega-3 fats and plant food, act in a synergistic way to improve gut health.

Vitamin D and Allergies

Here's a new paper that looks at Vitamin D supplements and allergies.  The author feels that the  increase in allergies is due to increased Vitamin D supplements, especially in baby food.  The full-text of the paper is available; it's an interesting hypothesis.

Better Bacteria

I've been looking more at the specific types of lactic acid bacteria.  Most of the probiotics you see at the grocery store are dairy-based, such as acidophilus.  Really though, this type of bacteria can't be Paleo because obviously dairy is not Paleo.

Other types of lactic acid bacteria, such as lactobacillus plantarum, come from vegetables.  This new study compared plant-based versus dairy-based lactic acid bacteria for digestion.  The plant-based bacteria had a better impact. 

This doesn't surprise me.  I've tried various probiotics, and I've found that the dairy-based ones never seem to have any positive effects for me.  Right now I am trying GoodBelly, which is a fruit drink containing lactobacillus plantarum.

Iodine

I am starting to see a lot of new research on iodine.  This is in some ways due to people trying to change their eating habits for the better.  As many people remove salt from their diet, they also remove iodine.  Seafood is another good source of iodine, but some people don't consume that.

I think what is happening with iodine parallels what happened with Vitamin D.  Enough evidence built up and now many people supplement with this basic nutrient.  I wouldn't be surprised if iodine is a commonly used supplement in 5 years time.

For example, this new study shows that correcting mild iodine deficiency in children boosts cognitive performance.  This study shows that iodine improves the lipid profile in children.

You can get iodine from natural sources such as sea vegetables (especially kelp).  However, a new study showed that many kelp supplements contained high levels of arsenic.  Therefore, it could be safer just to get iodine through supplement form.