This is a really subtle distinction, but the implication could be profound. Consider the following analogy: Think of the bruise you get on your shin when you inadvertently bang your leg into the coffee table. Sure, the bruise hurts like hell, and you almost certainly don't like the discolored look, but we all know the bruise per Se is not the problem. In fact, it's the opposite. It's a healthy response to the trauma, all of those immune cells rushing to the site of the injury to salvage cellular debris and prevent the spread of infection to elsewhere in the body. Now, imagine we thought bruises were the problem, and we evolved a giant medical establishment and a culture around treating bruises: masking creams, painkillers, you name it, all the while ignoring the fact that people are still banging their shins into coffee tables. How much better would we be if we treated the cause -- telling people to pay attention when they walk through the living room -- rather than the effect? Getting the cause and the effect right makes all the difference in the world. Getting it wrong, and the pharmaceutical industry can still do very well for its shareholders but nothing improves for the people with bruised shins. Cause and effect.
So what I'm suggesting is maybe we have the cause and effect wrong on obesity and insulin resistance. Maybe we should be asking ourselves, is it possible that insulin resistance causes weight gain and the diseases associated with obesity, at least in most people? What if being obese is just a metabolic response to something much more threatening, an underlying epidemic, the one we ought to be worried about?
Let's look at some suggestive facts. We know that 30 million obese Americans in the United States don't have insulin resistance. And by the way, they don't appear to be at any greater risk of disease than lean people. Conversely, we know that six million lean people in the United States are insulin-resistant, and by the way, they appear to be at even greater risk for those metabolic diseases I mentioned a moment ago than their obese counterparts. Now I don't know why, but it might be because, in their case, their cells haven't actually figured out the right thing to do with that excess energy. So if you can be obese and not have insulin resistance, and you can be lean and have it, this suggests that obesity may just be a proxy for what's going on.
So what if we're fighting the wrong war, fighting obesity rather than insulin resistance? Even worse, what if blaming the obese means we're blaming the victims? What if some of our fundamental ideas about obesity are just wrong?
Personally, I can't afford the luxury of arrogance anymore, let alone the luxury of certainty. I have my own ideas about what could be at the heart of this, but I'm wide open to others. Now, my hypothesis, because everybody always asks me, is this. If you ask yourself, what's a cell trying to protect itself from when it becomes insulin resistant, the answer probably isn't too much food. It's more likely too much glucose: blood sugar. Now, we know that refined grains and starches elevate your blood sugar in the short run, and there's even reason to believe that sugar may lead to insulin resistance directly. So if you put these physiological processes to work, I'd hypothesize that it might be our increased intake of refined grains, sugars and starches that's driving this epidemic of obesity and diabetes, but through insulin resistance, you see, and not necessarily through just overeating and under-exercising.
When I lost my 40 pounds a few years ago, I did it simply by restricting those things, which admittedly suggests I have a bias based on my personal experience. But that doesn't mean my bias is wrong, and most important, all of this can be tested scientifically. But step one is accepting the possibility that our current beliefs about obesity, diabetes and insulin resistance could be wrong and therefore must be tested. I'm betting my career on this. Today, I devote all of my time to working on this problem, and I'll go wherever the science takes me. I've decided that what I can't and won't do anymore is pretend I have the answers when I don't. I've been humbled enough by all I don't know.
Source: Is the obesity crisis hiding a bigger problem? - Peter Attia TEDMED 2013