Leptin & Your Weight: A Self-Regulating System

Excerpted from
The Fat Resistance Diet: Unlock the Secret of the Hormone Leptin
By Leo Galland, M.D.

The concept of leptin resistance marks a major advance in our understanding of weight gain and weight loss. Most of us, doctors and scientists included, have believed for a long time that body fat was simply an inert storehouse of unused calories. In that view, weight management was a simple matter-exercise more, eat less, and the pounds will drop; reverse the process, and your weight will rise. More recent dietary theories-low fat, low carb, Atkins, the Zone, and South Beach-vary the equation by blaming particular types of foods (fats or carbs), or by insisting on a particular proportion among foods (such as the Zone's 40:30:30 ratio for carbs, fats, and proteins) to achieve optimal weight loss.

But the latest weight-loss research suggests that all of these approaches miss the point. Fat is not an inert storehouse of calories. It is an active organ that produces its own hormones. In fact, our fat regulates itself. When we gain weight, our fat produces a hormone known as leptin that suppresses our appetite and speeds up our metabolism, causing us to lose the extra pounds we've just put on. At least, that's how it's supposed to work. If this process fails to operate, then our fat-regulating hormones aren't working properly and we suffer from the hormonal imbalance known as leptin resistance.

I'll say it again because I doubt you've ever heard it before: your fat is designed to regulate itself. When all your hormonal systems are functioning properly, you may gain a few pounds, but you will then lose them automatically.

The basis for this remarkable statement comes from one of the most exciting scientific breakthroughs to be made in recent years. In 1994, Jeffrey Friedman and his colleagues at Rockefeller University discovered leptin, a hormone whose main role-is to let the brain know how much body fat you have. If your body fat falls to a dangerously low level, leptin levels signal the brain to go into a state of emergency. Fertility is one of the first casualties. A woman with too little body fat can't ovulate or menstruate, because her body recognizes that she doesn't have enough fat to sustain a pregnancy or nurse a child. Leptin is a key messenger to convey this vital information.

On the other hand, if your body fat goes up past a certain point, what happens? Increased leptin levels signal your brain to suppress your appetite and speed up your metabolism. Leptin actually increases your resting metabolic rate-the rate at which your body burns calories when it is at rest. Clearly, a higher resting metabolic rate is another useful factor that can help us lose weight. And all of these beneficial effects result from a hormone that is produced by our own body fat.

Scientists' initial response to the discovery of leptin was to hope that human obesity was due to leptin deficiency, in the same way that childhood diabetes is due to a deficiency of insulin. What scientists discovered, however, was that overweight people have high levels of leptin-but their leptin isn't working properly. This condition has been labeled leptin resistance, and it has been compared to the insulin resistance (rather than insulin deficiency) that occurs in adult-onset diabetes. In leptin resistance, as in insulin resistance, there's nothing wrong with the hormone itself. The problem is that cells of your body cannot respond properly to the message the hormone is giving them.

The startling new understanding of body fat, which began with the discovery of leptin resistance, will soon change our view of obesity forever. It demonstrates that if you are completely healthy, and if you have access to enough nutritious food, you can maintain a healthy weight naturally, without having to think about it.

Unfortunately, most Americans are simply not this healthy. Thanks to improper diet, lack of exercise, excessive stress, and exposure to environmental toxins-the very hallmarks of modern life-our bodies are not regulating weight properly. It's not only that certain types of fats, sugar, and red meat are fattening, but they also contribute to weight gain through their promotion of inflammation. And inflammation plays a direct role in triggering leptin resistance. By disrupting our body's natural weight-maintenance mechanisms, leptin resistance leads us to gain even more weight.

The key to easy, permanent weight loss, therefore, is to correct the leptin resistance that causes our weight to rise. Once we've cured leptin resistance-a cure that requires eliminating some foods from our diet and adding others-our bodies will maintain a healthy weight of their own accord.

I made this important discovery in two ways. First, as I described in Chapter 1, I developed early versions of the Fat Resistance Diet while trying to help my patients suffering from asthma, arthritis, colitis, skin problems, and certain cardiovascular problems, all triggered by inflammation. As patients followed my anti-inflammation diet, their inflammation subsided-and their weight dropped. This occurred time and time again with overweight patients, even if the patient had no specific interest in weight loss. Thus, before anyone had diagnosed the condition of leptin resistance, I was curing it by prescribing healthy, anti-inflammatory foods.

Second, I followed the latest scientific research on inflammation and obesity. Over time, the articles I read in scientific journals began to illuminate the relationship between the inflammation I was trying to cure and the obesity from which

many of my patients suffered. As scientists advanced their discoveries, their findings helped to explain what I had already noticed: cure a person's inflammation through nutrition, and his or her weight will drop.

The final piece of the puzzle involved leptin resistance, which helped explain the deeper reasons why healing inflammation might help people restore and maintain a healthy weight. Once I understood the chain reaction-inflammation eventually led to leptin resistance, which in turn sabotaged weight-loss efforts - I understood that an anti-inflammatory diet could reverse the process and lead to permanent weight loss.

Now, if you think you've learned enough science for one day, feel free to skip ahead to Chapter 6 and start following the principles of the Fat Resistance Diet. You can successfully use the program I've outlined there without knowing anything more. But if you'd like to understand why the Fat Resistance Diet works so well and why it addresses so many health problems beyond obesity; read on. It's a fascinating story.