Saturday, April 16, 2011

Obesity and the Fluid-in, Fluid-out Therapy for Edema

I recently attended a lecture by Dr. Arya M. Sharma here at the University of Washington. Dr. Sharma is a Canadian clinician who specializes in the treatment of obesity. He gave the UW Science in Medicine lecture, which is a prestigious invited lecture.

He spent a little bit of time pointing out the fallacy behind conventional obesity treatment. He used the analogy of edema, which is an abnormal accumulation of fluid in the body.

Since we know that the amount of fluid contained in the body depends on the amount of fluid entering the body and the amount of fluid leaving the body, the treatment for edema is obvious: drink less, pee more.

Of course, this makes no sense. It doesn't address the underlying cause of edema and it will not help the patient. Yet we apply that exact same logic to fat loss. Since the amount of energy contained in the body (in the form of fat) depends on the amount entering and the amount leaving, the solution is easy: eat less, move more. Well, yes, if you can stick to that program it will cause fat loss. But that's equivalent to telling someone with edema to drink less water. It will cause a loss of fluid, but it won't correct the underlying problem that caused excessive fluid retention in the first place.

For example, if you have edema because your heart isn't pumping effectively (cardiac insufficiency), the heart is the problem that must be addressed. Any other treatment is purely symptomatic and is not a cure.

The same applies to obesity. If you don't correct the alteration in the system that causes an obese person to 'defend' his elevated fat mass against changes*, anything you do is symptomatic treatment and is unlikely to be very effective in the long term. My goal is to develop a method that goes beyond symptomatic treatment and allows the body to naturally return to a lower fat mass. I've been doing a lot of reading and I have a simple new idea that I feel confident in. It also neatly explains the results of a variety of weight loss diets. I've dropped a few hints here and there, but I'll be formally unveiling it in the next couple of months. Stay tuned.


* The body fat homeostasis system. The core element appears to be a negative feedback loop between body fat (via leptin, and insulin to a lesser degree) and the brain (primarily the hypothalamus, but other regions are involved). There are many other elements in the system, but that one seems to set the 'gain' on all the others and guides long-term fat mass homeostasis. The brain is the gatekeeper of both energy intake and energy expenditure, and unconscious processes strongly suggest appropriate levels for both factors according to the brain's perceived homeostatic needs. Those suggestions can be overridden consciously, but it requires a perpetual high degree of discipline, whereas someone who has been lean all her life doesn't require discipline to remain lean because her brain is suggesting behaviors that naturally defend leanness. I know what I'm saying here may seem controversial to some people reading this, because it's contrary to what they've read on the internet or in the popular press, but it's not particularly controversial in my field. In fact, you'll find most of this stuff in general neuroscience textbooks dating back more than 10 years (e.g., Eric Kandel and colleagues, Principles of Neuroscience).