The Diet Myth – Part 5 – Metabolic Crash and Burn

February 6, 2015

One of the first lessons I learned from my doctor while recovering from the effects of dieting is that many diets are entirely counterproductive.  Unlike what you might expect based on popularly-endorsed weight loss techniques, depriving your body puts it in a state of starvation.  Well, you might already know that you’re starving your body, but what you might not know is that this can have the opposite intended effect, causing you to gain – rather than lose – weight, with drastic long term repercussions.

Cut out one or more major macronutrient group (fats, carbohydrates, proteins), and your body will not only notice, but will try to become more economical over time.  The same goes for caloric restriction. No matter how you may have gained weight in the first place, your body wants to maintain the status quo and will adapt to do more with the less you’re giving it. 

Neuroscientist Sarah Aamodt discusses this phenomenon in her TED Talk, “Why Diets Don’t Work”, saying:

The hypothalamus, the part of the brain that regulates body weight […] works like a thermostat, responding to signals from the body by adjusting hunger, activity and metabolism, to keep your weight stable as conditions change. […]

Your brain works exactly the same way, responding to weight loss by using powerful tools to push your body back to what it considers normal. If you lose a lot of weight, your brain reacts as if you were starving, and whether you started out fat or thin, your brain’s response is exactly the same.

We would love to think that your brain could tell whether you need to lose weight or not, but it can’t. If you do lose a lot of weight, you become hungry, and your muscles burn less energy.

For a short while when I cut out carbohydrates, I shocked my system into burning more fat than normal as a replacement for the once-familiar energy it was no longer getting. At first it seemed effective – I was seeing results, getting compliments, and feeling good.  But, at some point, it moved away from burning fat in place of carbohydrates – it wanted to conserve this in case of an emergency, and the calorie deprivation I was putting it through was ringing all the metabolic alarm bells. So, it began burning muscle instead.

Likewise, this is where I suddenly began gaining weight and losing muscle even when I hadn’t changed my diet or exercise habits whatsoever.  Not only was my body was trying to get back to its “normal” point by gaining back all the weight I’d lost, but it also thought I was starving, even though I wasn’t.

Moreover, when I reintroduced carbs, everything went haywire – my newly calorie-efficient body started packing on the weight.  When you return to eating normally after any kind of deprivation diet, your metabolism does not necessarily recover from its suppressed state. This went completely against everything I’d ever seen in magazines, diet books, or even heard from doctors – including the many who had told me it was a simple matter of eating less and exercising more.  With so many diets out there and so many people professing success from the “calories in, calories out” or macronutrient elimination methods like eating low-carb, it seemed like nothing could go awry. After all, I wasn’t at risk of becoming anorexic.  Or, so I thought.

In actuality, the metabolism has many complexities beyond the thyroid, as Aamodt mentions in her talk. These are primarily regulated by your brain – specifically by the hypothalmus. Interestingly, a lot of what’s critical to maintaining, gaining, or losing weight is controlled by your brain.   One key hormone is leptin, along with others like MSH, ACTH, and ghrelin. Leptin is essentially your body’s self-perception of your weight. When you step on a scale, that’s how much you weigh in the external sense.  In contrast, leptin is essentially your body’s internal scale – it’s how much it thinks you weigh. This is an oversimplification, and there are many other factors at play, but that’s the gist of it.

Ideally, your leptin levels should be indicative of your actual body weight.  However, in my case, my leptin was incredibly low.  In fact, it was so low that from my body’s perspective, it thought that I was 40 pounds underweight. In reality, I was 20 pounds overweight.  So, while I wasn’t physically anorexic, I was, in a way, hormonally anorexic. This state was induced by dieting and underfueling both before, during, and after workouts. A deprivation diet combined with rigorous exercise had convinced my brain that my body was desperately underweight, just as Aamodt discusses in her talk. The New York Times article I linked in the first part of this series also mentions this phenomenon:

It is entirely possible that weight reduction, instead of resulting in a normal state for obese patients, results in an abnormal state resembling that of starved non-obese individuals.

What the Rockefeller study referenced in the New York Times article calls semi-starvation neurosis is what my doctor calls “diet fog” in her book The Metabolic Storm. She also explains how and why diets don’t work in this short podcast:

The “aha” moment for me was when I was treating anorexia patients. And then I realized that their test results were the same as many of my patients with obesity. And so I started to realize that what was really going on was starvation signaling that was slowing down the metabolism in the patients with obesity, as if they really were starving like the patient with anorexia was.

In fact, many of her patients were eating so little that it seemed impossible that they could possibly gain weight, but gain they did:

I have patients in that same situation who come to me and and are eating 500-800 calories a day and exercising, which is amazing, and they may weigh 300 or more pounds, and at some point they actually start gaining on these deprivation diets. And many doctors don’t believe them, and I think that’s the common belief – that they must be under-reporting their food intake and over-reporting their exercise.

But I know from experience that that’s not true, and also scientific studies have shown that even as little as 72 hours on a deprivation diet causes some hormonal changes to appear that are linked to what I call a ‘diet-induced weight defense system’ that starts to fight the weight loss and starts to try to swing your system the other direction.

She also discusses that most of your metabolic work is done in the brain, and how dieting affects those key signals:

Most of our weight and appetite regulation is happening in your brain, based on input signals from your body about whether you’re nourished and whether you’re carrying adequate body fat stores. And so the problem with dieting is it actually alters the very hormones that would be able to prove that to your brain.

So, it actually makes the hormones that say you have adequate body mass – it makes them crash, and actually decrease, while it makes the hormones that say you’re nutritionally deficient go up. Due to that, your appetite jacks up and your metabolism crashes and your body weight increases.

In my consultations with Dr. Cooper, she’s shared many stories of patients like myself who have gone through similar or worse situations. For example: one patient had gastric bypass surgery to induce weight loss, but the reduced caloric intake on top of her pre-existing (but formerly undiagnosed) metabolic issue actually compounded the issue, and she began gaining weight in spite of the surgery.

The gastric bypass was keeping her in starvation mode, which was consequently preventing weight loss. This may sound counterintuitive, but it just goes to show you how complex metabolic issues can be. She and my doctor were trying to get the surgeons to reverse the procedure so she could begin eating normally and convince her body (or, more accurately, her brain) that she wasn’t starving. However, at the time the surgeons refused because she hadn’t lost enough weight from the surgery. This is just one of many examples revealing that obesity is, both scientifically and medically, still a poorly-understood issue, and there still isn’t a “one size fits all” solution for anyone.

As for me: if I went for much longer on my low-carb, reduced-calorie, increased-exercise diet, it was likely that I would have started experiencing signs of anorexia, such as period cessation, even though I wasn’t physically anorexic.  Yes, it is possible for your body to act like you’re anorexic even if you aren’t, if your metabolic hormones get far enough out of balance. Yet, we are not talking an extreme diet here – I was still eating 1300-1500 calories per day, whole foods like chicken, fish, and veggies.  I was eating “healthy” according to a variety of online and offline resources, just avoiding carbohydrates like grains, legumes, potatoes, and other starchy foods.

Yet, there it was.  Looking at the numbers, it was clear that I had made a mess of things. This was the first step in a long process to getting my body back to normal, with more new discoveries yet to come.

Photo credit: Stéfan / Foter / CC BY-NC-SA


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