Read It Starts With Food: Discover the Whole30 and Change Your Life in Unexpected Ways Online
Authors: Melissa Hartwig,Dallas Hartwig
Leptin resistance means that you are gaining fat and swimming in leptin—but your brain is clueless, so it turns your metabolism down to conserve fuel, and tells you to eat more. And isn’t this all too easy to do when supernormally stimulating, nutrient-poor, carbohydrate-rich foods are whispering in your ear? Of course, overcarbsumption only promotes more sugar-burning for fuel, additional accumulation of body fat (and the conversion of excess carbohydrates to fat), and even-higher triglyceride levels in the blood.
Which makes your leptin resistance worse.
And … takes us back to insulin.
Remember insulin sensitivity? This is when insulin’s message to “store nutrients” is heard clearly by the cells, which remove glucose from the bloodstream and store it, keeping blood glucose levels from getting (or staying) high.
In contrast to insulin sensitivity, there is also a condition called
insulin resistance
. And …
Let’s recap: You chronically overconsume, because supernormally stimulating, nutrient-poor food has no brakes. This makes you leptin resistant, which means your brain thinks you are too lean (even if the mirror tells you otherwise). This leads your brain to tell you to eat more and move less, which promotes further overconsumption. You are now metabolically reliant on sugar for energy, you continue to accumulate fat in the body and the liver, and have excess glucose and triglycerides in your bloodstream.
All of that excess glucose needs to be stored. The trouble is, jamming lots of energy into a cell causes damage. So to protect themselves from being “overfilled,” the cells become insulin
resistant.
Once this occurs, the cells lose their sensitivity to insulin’s message to store nutrients: the pancreas sends a message (via insulin) to “store,” but the cells don’t listen, and blood sugar levels remain high.
Since high levels of blood sugar are
very
unhealthy, the body really needs the cells to store that energy—so it responds with an even stronger message. Insulin resistance requires that the pancreas produce even
more
insulin, until the message is strong enough to
force
nutrients into the already-f cells. However, this “force-feeding” creates oxidative stress and elevated fat levels in the blood, which further damages the cells. The damaged cells continue to try to protect themselves, further increasing insulin resistance … and the cycle continues.
These cells, overfilled and running mostly on sugar, produce “reactive oxygen species” (which you probably know as “free radicals”), which cause cellular damage. The response to this damage is a cascade of immune responses, including the release of inflammatory chemicals, as well as immune cells that show up as “first responders” to help repair the damaged tissue. This immune response is termed
systemic inflammation
(we’ll get to this soon), and further increases insulin resistance.
At this point, you have excess glucose in a system that is insulin resistant. Blood sugar
remains
high because the cells are stuffed and resisting insulin’s message to store. This creates ongoing hyperglycemia—chronically elevated levels of blood sugar. Which, as you recall, is very damaging—specifically to pancreatic beta cells, where insulin is produced.
Chronic hyperglycemia first causes beta cell adaptation, to allow the pancreas to produce progressively more insulin to manage the excess blood sugar. The pancreas can’t adapt forever, however. Eventually, damaged by ongoing hyperglycemia
,
pancreatic beta cells start to disintegrate. Yes, they actually
die
from toxic levels of blood sugar and the resulting oxidative stress.
At this point, you lose the ability to produce enough insulin to manage blood sugar—which is how toxic levels of blood sugar and insulin resistance can lead to type 2 diabetes.
However, there are consequences to your health
long
before you get to diabetes. Hyperglycemia (chronically high levels of blood sugar) is damaging, but hyperinsulinemia (chronically high levels of insulin) is
profoundly
damaging, and a clear risk factor for major lifestyle-related diseases and conditions, like diabetes, obesity, heart attack, stroke, and Alzheimer’s disease.
When you are insulin resistant (and, thanks to leptin resistance, you continue to overcarbsume), the pancreas needs to secrete ever-increasing amounts of insulin to pull glucose out of the bloodstream. Since your blood sugar regulation mechanism no longer works properly, all that insulin can pull blood sugar levels too far in the
other
direction—what was
too high
is now
too low
(a condition often referred to as “reactive hypoglycemia”). Too low comes with its own set of side effects—cranky, tired, foggy, and, thanks to constant appetite dysregulation,
hungry
. To you, this translates as, “Must. Eat. Sugar.” Your body doesn’t actually need calories, but thanks to the messed-up messages your body is sending—you’re too lean, your blood sugar is too low—you give in to the same foods (supernormally stimulating and nutrient-poor) that got you into trouble in the first place. It’s a vicious cycle—and it could be worse. If you don’t change your eating habits pronto, insulin resistance very well could progress to type 2 diabetes.
Type 2 diabetes occurs when (because of the severity of insulin resistance and beta cell death) your body can no longer produce enough insulin to keep your blood sugar within healthy parameters.
This is very,
very
bad—especially if your diet still doesn’t change.
Diabetes comes with its own list of side effects and related conditions: obesity, glaucoma and cataracts, hearing loss, impaired peripheral circulation, nerve damage, skin infections, high blood pressure, heart disease, and depression. Tens of thousands of people die of complications from diabetes every year.
Nobody wants diabetes. In fact, nobody wants
any
of this—the primary reliance on sugar for energy, the ongoing accumulation of body fat, ineffective hormonal messages, energy peaks and crashes, relentless hunger, long-term health consequences. …
This
is why a healthy hormonal response is one of our four Good Food standards, and why we advocate for eliminating foods that promote an unhealthy metabolism.
But there’s more to the story.
And we assure you, there is good news.
First, let’s discuss glucagon.
Summary: A catabolic (“energy access”) hormone secreted from the alpha cells of the pancreas in response to the demand for energy, either as a result of activity or after several hours without eating (“fasting”). Glucagon unlocks the one-way door out of storage cells (like liver and fat cells), and allows you to access the energy you’ve previously stored. Chronic stress, protein intake and low blood sugar levels stimulate glucagon release. Glucagon’s function is inhibited by elevated insulin and free fatty acids in the blood.
Were the scientists who named this stuff
trying
to confuse us? Let’s recap our three G’s before we move on.
Glucose
is one form of sugar found in food and is also the type of sugar circulating in the bloodstream.
Glycogen
is the stored form of glucose, found in the liver and muscles.
Glucagon
is the energy access hormone, which triggers the conversion of glycogen in the liver back into glucose and releases it into the bloodstream for use as energy elsewhere in the body. Got it? Good.
There is normally about five grams (a teaspoon) of blood sugar circulating in your bloodstream at any given time. However, for various reasons—when we’re under stress, when we haven’t eaten in a long time, or when we’ve had the low blood sugar rebound previously described—our blood sugar “temperature” can get too low. (The science-y term for this is “hypoglycemia.”) Since glucose supply to the brain is literally a matter of life or death—you’ll go into a coma if blood glucose levels dip extremely low—your body has multiple fail-safe mechanisms to ensure that doesn’t happen. One of these mechanisms works via a hormone called
glucagon
.
Just as insulin is the “air conditioner” for safe blood glucose levels, glucagon functions as the “heater,” preventing blood sugar levels from falling too low and giving us access to energy we’ve previously stored. When the body senses a dip in normal blood sugar levels, alpha cells in the pancreas release glucagon. Glucagon then tells the body to break down stored fat and convert stored liver glycogen (and, if necessary, protein from your muscles) into glucose, trickling it into the bloodstream to provide you with energy and keep blood sugar levels normal.
There is a caveat.
Glucagon can tell the cells to release stored energy—and use body fat—
only
when there’s not a lot of circulating insulin. After all, if insulin is elevated, nutrients are being stored as fast as they’re being mobilized—or faster. Which means that when insulin levels are elevated (even moderately), the net effect is more energy storage than energy access.
When you are insulin resistant and eat a high-carb meal, insulin levels stay high and “echo” throughout the body for a few hours. Between meals, when you should be tapping into your fat stores for fuel, you can’t—because insulin is
still
talking, and glucagon can’t get a word in edgewise.
Strike seventeen against dietary habits that chronically elevate blood sugar and, in turn, promote leptin and insulin resistance. The takeaway:
We’re almost done, so hang in there. We just need to introduce yet another hormone related to overcarbsumption, insulin resistance, and … stress. Say hello to cortisol.
Summary: The “stress hormone” secreted from the adrenal glands to help the body recover from an acute fight-or-flight stress response. It is secreted in response to low blood sugar, physical or psychosocial stress, intense and prolonged exercise, and sleep deprivation. Cortisol plays a key role in salt metabolism, blood pressure, immune function (having immunosuppressive and anti-inflammatory effects), and energy regulation. It raises blood sugar by stimulating glycogen breakdown. Chronically elevated cortisol promotes insulin resistance and tends to elevate leptin levels.
Cortisol has a circadian rhythm that coincides with the light-dark cycle. Cortisol is highest just before waking, functioning as a “get up and go” hormone during the early morning hours. It mobilizes energy for activity and helps to fire up your nervous system so that you (mentally) feel more like Einstein than like Homer Simpson. Cortisol levels then decline rapidly as the day progresses, remaining low in the late evening and overnight, helping you to relax before bed and sleep well until morning.
It’s normal to have higher cortisol levels first thing in the morning, but artificial light (including the light from your TV, computer, and mobile phone) after dark tells your body it’s still daytime. This does not allow you to hormonally “wind down” in the evening, which promotes that “tired but wired” effect. Sending your brain daytime messages right before bed also upsets normal hormonal responses (like melatonin secretion) when you’re sleeping, so you don’t get adequate deep, restorative sleep. That sleep, and normal cortisol rhythms, are important for memory formation and future access. Now, where did you put your highlighter?
Cortisol secretion is tied to many factors (like sleep, exercise, and psychological stress) but is also influenced by your eating habits. One of cortisol’s jobs is to help glucagon keep blood sugar within a healthy range. When your body senses that blood sugar is too low (like when you haven’t eaten for a very long time) or if it crashes too fast (as they tend to do following a blood sugar spike when you’re insulin resistant), it reacts to that stressful situation by releasing cortisol. Cortisol then prompts glucagon to get to work, breaking down energy stored as liver glycogen (or muscle tissue) and flooding it into the bloodstream as a response to your volatile blood sugar levels.
The trouble comes when your actions (dietary or otherwise) tell your body that you’re very stressed
all the time
. This causes your adrenals to release cortisol
all the time
. And when cortisol gets rowdy, it creates all sorts of trouble—some of which is going to sound awfully familiar.
Being chronically underslept, constantly over-exercising, or experiencing chronic psychological stress—a hallmark of modern life—can all trigger unhealthy levels of cortisol in the body. But so can prolonged periods of not eating (extended fasting), or eating too little (excessive calorie restriction).
Fasting—when you don’t eat for eight, twelve, sixteen hours—is somewhat stressful to the body and may elevate cortisol levels, which only adds more stress to your already overstressed system. Cutting too many calories (which we’re pretty sure you’ve done before) is also profoundly stressful and also elevates cortisol levels.
Want to know another reason that skipping meals and restricting your calories doesn’t work for long-term weight loss? Because chronically elevated cortisol sends a variety of messages via different hormonal pathways, all designed to do one thing—
preserve body fat
. In fact, chronically elevated cortisol levels actually erode your muscle mass, leaving you with more fat and less muscle.
Now we have your attention.
Chronically elevated cortisol impairs glucose uptake from the bloodstream
and
enhances the breakdown of glycogen in the liver—both leading to more glucose in the blood. To make matters worse, cortisol also inhibits insulin secretion from the pancreas.