Although many scientists glibly refer to ghrelin as the “hunger hormone,” it’s got plenty of partners when it comes to making people eat or stop eating. In fact, more than twenty chemical messengers have been found to stimulate eating, and a similar number suppress appetite.
While ghrelin plays the starring role as an appetite trigger, leptin, insulin, and another gut hormone, PYY, turn down the dial on ghrelin response. These hormones, and others, travel through the body carrying their indulge-or-don’t messages. They also trigger nerve messages to the brain and are influenced, in turn, by messages returning from the brain.
To complicate the picture, other events occurring in your body mediate these messages. Your emotions, for example, generate chemicals that send potent messages to the same sites that respond to leptin and insulin. Your sleep patterns also influence this system.
With such a degree of complexity, it’s no wonder that we’re struggling with the question of how to influence our weight in a meaningful and lasting way!
Feast or Famine Genes
To understand just why our modern lifestyles throw our internal weight meters out of whack, you first have to understand this genetic compulsion we have to hang on to every calorie, and why that is so at odds with the world we live in today. For that, I’d like to introduce you to your great-great-great-great-great-great-grand-mother.
Her picture might not be hanging in your living room, but you—like every other human on this planet—descended from early humans to whom “dinner” might come just once every few days. Given the scarcity of food and the tremendous amount of calories expended catching it (think running after mammoths with spears), it’s no surprise that our bodies evolved to be super-efficient at energy conservation, genetically wired to hang on to every calorie while they urge us to seek out the highest calorie food we can find. All long before the first food court, of course, where high calorie food is easily obtained.
Today, even though we can eat dinner all day long if we want and expend no more calories than it takes to breathe, digest, and click the remote control, this genetic propensity has remained largely unchanged.
In fact, through evolution we’ve created a population more likely than not to have these “thrifty genes.” That’s because throughout human history, those at greatest risk of starving to death were those who burned energy quickly and could not store fat—like that size 4 woman you may know who never diets or exercises and eats whatever she wants. Because women (and men) like her couldn’t survive during lean times (no body fat to burn), their numbers dwindled in our gene pool. We just didn’t need the skinny folks!
The rest of us, then, descended from the survivors, those with a very efficient system for storing fat whenever food was available. Given today’s environment, you can see how our genes set us up to pack on some padding.
To put it in the proverbial nutshell: Our internal weight regulation system remains ideally crafted for the environmental condition of the past—food scarcity—helping us pack on pounds and thwart hunger and has yet to evolve for the environment of today, where food is everywhere and we’re more likely to burn a CD than a calorie. The advent of cooking and the ability to strip certain nutrients (like sugar or fat) from other more nutritious and filling components (like fiber) also made it a lot easier to get calories into our bodies.
Add to this the increased dieting of today which, in our genetic memory, feels an awful lot like the famines of yore. Combine changes in the
of foods we’re eating; and changes in
we’re eating, and you have a recipe for, you guessed it, higher setpoints and creeping weight gain.
Type 2 Diabetes and Our Genetic Heritage
Throughout most of our evolutionary history, food shortages were common. When food was abundant, people who produced lots of insulin (a hormone that helps you get glucose—and fat—into your cells) could gorge since this insulin enabled them to store excess energy as body fat. This was an evolutionary advantage, since they could live off their fat during famines. Those who couldn’t produce as much insulin starved.
Fast-forward to today and our typical American diet in which we’re challenged to pour out insulin all the time (more on that soon). What happens? The abundance of insulin overwhelms our cells to the point that they react less to its message. What was once an evolutionary advantage given frequent famines and inconsistent meals now leads to insulin resistance, particularly in hardworking muscles that could potentially burn that extra energy. Our fat cells, on the other hand, don’t develop this insulin resistance. Instead, they readily respond to insulin’s storage message and extra glucose gets converted into fat and stored as fat. A fine evolutionary safeguard for the past when fat storage was valued, not so well appreciated today.
What Does It All Mean?
I know I’ve given you a lot of information in the preceding pages. If you need a little help assimilating it all, here’s a cheat sheet:
• Your fat cells are not just dumb sacks of lard. They are active organs and send chemical messages that help to regulate many body functions.
• Your brain receives moment-to-moment messages from your fat cells so it is well informed about how much energy is in your fat stores.
• Your brain also receives moment-to-moment messages from your digestive tract, making it well-informed about your overall nutritional status.
• Your brain also receives signals stimulated by physical activity, emotion, sleep patterns, and other goings-on.
• Your brain assimilates this wealth of information and, in response, produces chemical messengers and nerve responses that regulate your appetite and metabolism, affecting not only when you experience hunger but also what foods appeal to you and how much food it takes to make you feel full. Although you’re not aware of these chemical changes, they drive your behavior, moving you toward the table or instructing you to turn down seconds.
• Your body likes to maintain the status quo and keep your weight relatively stable; this range of stable weight is called your “setpoint.”
• Your body strongly protects against dipping below your setpoint, though most people’s bodies are relatively less aggressive at preventing them from rising above their setpoint. In other words, weight gain is relatively easy at the same time that weight loss may not be possible.
• When you lose weight and threaten this system, your body may react by raising your setpoint, protecting against future threat.
The Final Result ?
Your body maintains whatever it perceives as an adequate amount of fat storage to protect itself. How much fat protection your body requires (your setpoint) is the result of a complex interplay of genetics and the lifestyle choices made today as well as in the past—and is intimately linked to your current weight.
This, in turn, leads to the catch-22: Your body wants to maintain the status quo and is stubbornly resistant to change. When you lose body fat, the very loss of fat triggers processes to reclaim it. So losing weight in and of itself is counterproductive to maintaining weight loss. We shouldn’t be too surprised that weight loss is so rarely maintained.
What’s My Setpoint?
Unfortunately, there’s no magic formula or laboratory test to determine your setpoint. Nor is there any objective way to figure out how tightly yours is regulated. (Scientists estimate that the average person has a setpoint range of about ten to twenty pounds, meaning at any given time, there is a ten-to-twenty-pound range at which your body will be comfortable and not resist attempts to change. So losing /gaining small amounts of weight may not be difficult and won’t be met by compensatory actions, if you are within your setpoint range.
find your own setpoint. How? By listening to your body and eating normally. You’ll learn more about how to do that throughout this book.
Are You Above Your Setpoint?
Wondering if you’re above your own setpoint? Then answer these questions:
• Do you have difficulty recognizing when you’re hungry and when you’ve had enough?
• Do you routinely eat beyond a comfortable level of fullness and feel lethargic, stuffed, and uncomfortable after meals?
• Do you go through periods where you eat out of control, anticipating that you will soon start to diet?
• Do you skip meals in an effort to lose weight, then overeat because you are so hungry?
• Do you skip meals to “save up” for a big feast?
• Do you often eat as a coping mechanism? For example, when you’re tired, angry, or nervous? How about killing time when you’re bored?
• Do you often feel guilty about some of the foods or the amount of food you eat?
• If you overeat, do you figure you’ve blown your “diet” and end up eating even more?
• Do you often eat quickly without taking the time to focus on the taste of your food or to savor and enjoy it?
• Do you fluctuate between periods of sensible, nutritious eating and then eating out of control?
If you answered “yes” to any of these questions, you are likely above your setpoint. Don’t feel bad! Most people aren’t at their setpoint. This book will help you find it.
Warning: Many of these conditions may also be symptomatic of an eating disorder or other concerns. Be sure to discuss these symptoms with a trusted health professional.
Are You Below Your Setpoint?
Some people are chronically below their setpoint. You’ll know this is you if:
• You feel like you’re constantly preoccupied with food and often feel desperately hungry.
• You wake up with an overwhelming urge to eat.
• You have difficulty sleeping because of gnawing hunger.
• You have a very low sex drive.
• For females, you have infrequent periods or skip them entirely.
• You suffer from any of the following: apathy, fatigue, irritability, and/or depression.
If you are below your setpoint, learning how to respond to your body’s signals will help you to normalize your eating habits and feel better. It may result in a slight weight gain, but this is a good thing, I assure you!
Warning: Many of these conditions may also be symptomatic of an eating disorder, a thyroid dysfunction, or other concerns. Be sure to discuss these symptoms with a trusted health professional.
This book is going to help you get to your natural setpoint, the weight that is healthiest for you. By the end of the book, you’ll be answering “yes” to these questions:
• Do you eat naturally in response to signals of hunger, fullness, and appetite without fixating on your weight or food habits?
• Is eating effortless and enjoyable?
Soon, your body will be guiding you in making nutritious, pleasurable choices. No more counting calories, totaling fat grams, or weighing broiled skinless chicken breasts!
We’re Emotionally Starved
kay, so you know you have an internal weight regulation system that is predisposed to maintaining your individual body weight setpoint. If it’s so powerful, you’re wondering, how come our waistlines have been expanding over the last few decades?
Two reasons: First, we no longer allow the process to work. We don’t trust our own judgment anymore. External rules, such as belief systems about good foods, bad foods, or appropriate amounts or times to eat, drown out our innate ability to respond to setpoint cues. We eat not because we’re hungry, but because we’re sad, guilty, bored, frustrated, lonely, or angry. And because food can’t take care of our emotions, we eat and eat and never feel satisfied. We’ll tackle these topics in this chapter.