I am exploring the theory that obesity is an immune disorder. This follows up on a previous post, where researchers speculate that obesity should be viewed in light of the hygiene hypothesis. What you see is increasing rates of asthma, allergies, and obesity in society, and the theory is that a weakened immune system is the basis of it all.
Based on what I've read, things start in the womb. But most researchers are focusing only on diet, and how simple carbohydrates can lead to insulin resistance. I think this is partly true, but the basis of origin may be gut flora. Sugar can distub this, but so can other factors. The hygiene hypothesis says that a lack of dirt/germs doesn't allow the immune system to develop properly. I would add to this that a lack of Vitamin D weakens the immune system as well (and vice versa). Recent research supports this.
In short, I think that the combination of germs and sunlight in traditional cultures and older times kept immune systems healthy. As these two factors have diminished, immune systems have weakend and this is being passed on from generation to generation. Luckily, you can somewhat reverse this with modern supplements: Vitamin D pills and probiotics.
Now, here's some evidence to support all this speculation. Researchers have found a link between obesity and gum disease. Now you might think this has the same cause: poor eating. But look at what improved gum disease: probiotics. And this was achieved by rebalancing bacteria in the gut, and not the mouth: " probiotics may be immunomodulatory rather than direct effects on the microbiota of the oral cavity."
An earlier post I had showed that baseline Vitamin D status predicted weight loss on a diet. This would support the idea that changes in the immune system are driving changes in weight rather than the other way around. You also look at this study that showed how gastric bypass patients that took probiotics lost more weight than those who didn't. There is also a new study showing how probiotics led to less visceral fat in women who recently had children.
If all this turns out to be true, it suggest a paradigm shift for reducing weight. Instead of cutting calories, people would focus on improving their immune systems through Vitamin D, probiotics, and of course, diet.
It makes sense to look at other conditions like asthma and allergy through this lens, so why not obesity? For example, you can treat asthma and allergies with medication, but that doesn't really get at the root cause. In a similar way, you can treat overweight/obesity by cutting calories, but does that really get to the root cause? The answer may be in the immune system and the gut flora.