The Blog

Featuring fresh takes and real-time analysis from HuffPost's signature lineup of contributors

Mark Hyman, MD Headshot

Are Your Food Allergies Making You Fat?

Posted: Updated:

Your digestive system may be making you fat. It's hard to believe - but very true!

Today, I'm going to explain the bugs in your digestive tract, why they upset your gut's immune system, and how they just might be behind those extra pounds.

I have observed this phenomenon in hundreds of patients. Recently, remarkable new research has confirmed this phenomenon. I have developed very effective treatments for it, based on understanding the way in which all the body's systems -- the gut, the immune system, detoxification system, hormones and more -- are connected.

There's powerful evidence that addressing these key causes of weight gain and illness can help you shed pounds.

For example, I've seen patients who lose significant amounts of weight, just by cutting food allergens from their diet. And I have also seen people lose 20 to 30 pounds, simply by balancing the bacterial ecosystem in their intestinal system.

One patient, a 38-year-old woman, had chronic inflammation, fluid retention, acne, fatigue, and joint pain, as well as irritable bowel syndrome with bloating and gas. She had tried every known diet, but was unable to lose weight.

This woman's problem: She could not lose weight because she was inflamed. Imbalances in her gut and the food sensitivities that result led to the inflammation.

But when we had her eliminate the foods to which she was allergic or sensitive, and gave her some healthy bacteria to heal her gut, she lost 35 pounds in a few months - and all her other symptoms went away too.

The big debate in medicine is which comes first: inflammation or obesity. I have always believed that we become inflamed first, and gain weight second - which makes us even more inflamed, perpetuating the cycle. Now incredible new research bears this out.

In today's blog I want to review this research, explain how food allergies can lead to weight gain, and provide you with three steps you can take to eliminate foods you may be allergic to and rebalance the ecosystem in your gut.

Inflammation and Weight Gain

Let me tell you a little more about these studies linking inflammation and weight gain, and explain their implications for treating obesity, heart disease, diabetes, and more.

Both studies were done in Europe, where researchers are generally more open-minded.

The first study, published in December 2007, looked at two groups of children. The first group was overweight and the second was normal weight. (i) The researchers measured three key factors connected to inflammation.

First, they looked at high-sensitivity C-reactive protein (CRP), a marker that shows the general level of inflammation in the body. Then they looked for plaque or thickening in the carotid arteries (the main arteries that supply the brain) with an ultrasound. Third, they looked at blood tests for IgG, or delayed food allergies.

What they found was startling.

The overweight kids had a 3-fold higher level of CRP and a 2.5-fold higher level of IgG antibodies to foods. This is astounding, since in most medical studies a difference of 20 to 30 percent is considered significant. And in this case, the differences were 300 and 250 percent, respectively.

The overweight children also had much thicker carotid arteries, which are a sign of early atherosclerosis and an indicator of heart disease.

The study suggests that these food allergies are a CAUSE of the inflammation and obesity, not a consequence.

The authors of the study explain that damage to the gut can lead to a leaky gut, allowing food particles to be exposed to the gut's immune system. This then triggers a system-wide immune response, leading to inflammation all over the body and producing obesity by increasing insulin resistance.

We already know that inflammation from any cause -- bacteria, food, a high-sugar, high-fat diet --- will produce insulin resistance, leading to higher insulin levels. And since insulin is a fat storage hormone, you store more fat -- mostly around the belly.

The authors of the study go on to say that we should consider elimination of IgG food allergens as a way of treating obesity and preventing heart disease. That means you don't limit calories, just allergic foods that cause inflammation.

This study draws a remarkable link that has received little attention by conventional medicine.

So what exactly causes a leaky gut? Well, the next study may help explain just that.

How Your Gut Begins to Leak

The researchers of a study published in the July 2007 issue of Diabetes, performed a complex but powerful study to tease out which comes first - the chicken or the egg. (ii)

What they did was quite ingenious. They took thin mice and then fed them a very high-fat diet.

High-fat diets change the bacterial flora in the gut. Toxin-producing bugs are promoted by the high-fat diet while anti-inflammatory and protective bugs die off. (And there are over 500 species of bugs in your gut all fighting for territory.)

In fact, our highly processed, high-sugar, high-fat, low-fiber diet - plus many drugs like antibiotics, steroids, anti-inflammatories, acid-blockers, and hormones - completely alters the bacterial ecosystem in the gut, leading to breakdown, inflammation, and a leaky gut.

Back to the study.

The researchers found that mice fed the equivalent of an American diet produced more of a bacterial toxin called LPS, which then leaked into the body through their leaky gut.

In humans, these toxins then latch onto immune cells, stimulating them to produce a firestorm of inflammatory molecules such as TNFa, IL-6, and IL-1 (cytokines), which in turn block your metabolism and produce insulin resistance, fatty liver, and obesity.

Even more interesting, the researchers also found that even with a normal diet, injecting LPS into the mice led to the SAME problems - inflammation and obesity. These mice didn't eat a bad diet. Just injecting toxins into them made them fat.

In fact, when you eat a bad diet, bad bugs flourish. Your whole gut ecosystem is upset and the outside world "leaks" in across a damaged gut lining. The result is not just obesity, diabetes, and heart disease, but so many allergic, autoimmune, and inflammatory diseases.

The researchers explain how giving antibiotics to rats and cleaning out the bad bugs can prevent diabetes. They explain that by adding soluble fiber to the diet, they can increase the population of the good bugs like Bifidobacteria and decrease the bad bugs - leading to weight loss.

But it doesn't just happen in lab rats. I have found the same effects when my patients take the special soluble fiber called konjac root or glucomannan. The good bacteria feed on the fiber and reduce inflammation.

And there is more to the gut story. It seems that you are not the only one eating lunch. The bugs in your gut also feast - and they control your fat storage and the calories you absorb. So people with healthy bugs in the gut lose weight, and those with bad bugs gain weight. (iii)

Let me review this briefly again, because these concepts are so far from what we normally think about the causes of obesity.

When you eat a typical American diet, you foster the growth of bad bugs in the gut. They then damage the gut lining and produce toxins that are absorbed into your system.

Because of the damage, partially digested food particles also leak into your bloodstream. Then your immune system reacts to the toxins and foods, producing a firestorm of inflammation.

That inflammation then leads to a fatty toxic liver and insulin resistance, which lead to higher levels of insulin in your body. And insulin is a fat-storage, disease- and aging-promoting hormone.

So an unhealthy gut makes us fat and sick because it makes us toxic and inflamed.

This is groundbreaking research that needs to shake up our thinking about how to help people lose weight and get healthy.

Now here are a few simple things to try if you are struggling to lose weight or feel better.

3 Steps to Eliminate Food Allergens and Rebalance Your Gut Ecology

1. Try an elimination diet for 3 weeks. Cut out the most common food allergens, including gluten, dairy, eggs, corn, yeast, and peanuts. Some people are sensitive to soy, so you can also cut that out.

2. Eat a whole-foods, plant-based, high-fiber diet. This is essential to feed the good bugs in your gut and to provide the nutrients you need to functional optimally.

3. Take probiotics daily to boost the healthy bacteria in your gut. Look for those that contain 10 billion CFU of bifidobacteria species and lactobacillus species. Choose from reputable brands.

Within a very few short weeks -- even if you do nothing else -- you will see a dramatic difference that comes from cooling off inflammation by healing your gut.

Remember, if you want to get rid of that gut, you have to fix your gut.

Now I'd like to hear from you...

Have you noticed that inflammation is affecting your weight?

What steps do you plan to take to reduce inflammation?

How has reducing inflammation affected your weight?

Please let me know your thoughts by posting a comment below.

To your good health,

Mark Hyman, M.D.

References

(i) Wilders-Truschnig M, Mangge H, Lieners C, et al. IgG Antibodies Against Food Antigens are Correlated with Inflammation and Intima Media Thickness in Obese Juveniles. Exp Clin Endocrinol Diabetes. 2007 Dec 10

(ii) Cani PD, Amar J, Iglesias MA, et al. Metabolic endotoxemia initiates obesity and insulin resistance. Diabetes. 2007 Jul;56(7):1761-72.

(iii) Backhed F, Ding H, Wang T, et al. The gut microbiota as an environmental factor that regulates fat storage. Proc Natl Acad Sci U S A. 2004 Nov 2;101(44):15718-23. Epub 2004 Oct 2

Mark Hyman, M.D. practicing physician and founder of The UltraWellness Center is a pioneer in functional medicine. Dr. Hyman is now sharing the 7 ways to tap into your body's natural ability to heal itself. You can follow him on Twitter, connect with him on LinkedIn, watch his videos on Youtube and become a fan on Facebook.

From Our Partners