The Hungry Brain: Outsmarting the Instincts That Make Us Overeat

by Stephan Guyenet

aaaaaaaaaaaaaaaaahhhhhh! this is my research!!!

Sclafani called this phenomenon conditioned flavor preference.

Humans also have a strong preference for salt (sodium chloride)—one inclination we don’t share with rats.

how interesting. animals that dont sweat arent as preferring of salt.

Our gastronomic similarity to rats is supported by the research of Leann Birch, a childhood obesity researcher at the University of Georgia, whose research team set out to see if they could extend Sclafani’s results to humans.43 Their findings, and those of other researchers, show that certain nutrients, especially fat and carbohydrate, can indeed condition flavor preferences in our own species. In other words, they reinforce behavior. In

Certain modern foods likely provoke a larger release of dopamine than the human brain evolved to expect, leading to destructive addiction-like behaviors in susceptible people.

As Gearhardt and Brownell alluded to, this is similar to how drugs of abuse are often concentrated versions of less-addictive naturally occurring substances. For example, the leaves of the coca plant are widely chewed in South America as a mild stimulant and appetite suppressant reminiscent of caffeine. However, when we extract and concentrate the active ingredient of the coca leaf, this results in a much more addictive substance: cocaine.

meal ceremony,

this is a very surprisingly reverent way to ddescribe eating food.

In 2010, Chris Voigt, the director of the Washington State Potato Commission, decided to eat nothing but potatoes and a small amount of cooking oil for sixty days. Voigt was protesting a decision by the federal Women, Infants, and Children food assistance program to remove potatoes from the list of vegetables it will pay for.51 Voigt contended, correctly, that potatoes are actually quite nutritious—in fact, one of the few foods that provide a broad enough complement of nutrients to sustain a human in good health for months at a time.52 He documented his journey on a Web site titled 20 Potatoes a Day, which refers to the number of potatoes he would have to eat to maintain his weight. Voigt signed himself up for two months of a starchy, bland, repetitive diet. Despite Voigt’s goal not to lose weight, the pounds melted off. He lost twenty-one pounds over the sixty-day period, much of it from his waistline. According to physical examinations before and after, his blood glucose, blood pressure, and cholesterol levels improved considerably. He had trouble eating enough to meet his energy needs because he simply wasn’t hungry. While we may be tempted to question the veracity of a person whose job involves promoting potatoes, Voigt’s experiment triggered an avalanche of Internet copycats who used the “potato diet” for rapid weight loss. Although anecdotal, their reports suggest that eating this bland, repetitive diet does indeed reduce spontaneous calorie intake without provoking ...

share with michael.

The fact that sensory-specific satiety drives us to overeat suggests a simple solution to the problem: Limit yourself to a few foods.

A young woman stares intently at a computer screen in Leonard Epstein’s lab at the University at Buffalo in New York. She’s playing a slot machine computer game. Each time she clicks the mouse button, three columns of shapes spin on the screen and then settle. If the shapes are different from one another, she gets nothing—but if they line up, she gets a point. While it may sound like she’s goofing off, in fact she’s participating in a series of fascinating studies that are beginning to shed light on why some people become obese and others don’t. Once she earns two points, she gets a small piece of a candy bar. While she only needs two points to receive a candy bar the first time, the next time, she must earn four points to receive the same candy bar, and then eight. “We keep increasing the work requirements,” explains Epstein, “until eventually the person says, ‘Jeez, it’s just not worth it.’” The number of responses she’s willing to make before quitting quantifies how hard she’s willing to work for food.56

a human model of the lever press studiesin rodents!

To begin to explore the question of whether a high RRVfood actually causes weight gain, Epstein and other researchers went back in time.

"where we're going, we don't need peer review."

These findings suggest that people differ in their motivation to eat food, particularly highly rewarding foods, and that this is a stable personality trait that influences each person’s susceptibility to weight gain over time.

This offers a partial answer to the question posed earlier: Heightened food reward sensitivity does seem to contribute to overeating and fat gain over time.

Working hard for food makes a lot of sense when it’s the only way to survive. Throughout most of human history, and long before, our ancestors spent the bulk of their lives collecting, hunting, growing, and eating food—and it was often hard work. Without a powerful instinctive drive to obtain and eat food, we wouldn’t have survived at a time when securing food demanded so much effort. We still carry that instinct today, but in th...

As Epstein puts it, “If you find something really rewarding and you have really poor impulse control, you’re in a lot of trouble.”

Epstein coined the term reinforcement pathology to describe the dangerous combination of high reinforcement sensitivity and high impulsivity.

Without industrialized agriculture, I wouldn’t be writing this book,

ffs this is why there are acknowledgement sections.

Of the 2.6 million years since our genus Homo emerged, we were hunter-gatherers for 99.5 percent of it, subsistence-level farmers for 0.5 percent of it, and industrialized for less than 0.008 percent of it.

First, they include a limited variety of foods. For example, although the!Kung San recognized at least 105 plants as edible, only 14 formed the bulk of their plant food intake, and only a subset of these 14 plant foods was available at any given season and location. Throughout the year, half of their calorie intake came from a single food, the mongongo fruit/nut. Over the course of the entire year, the!Kung San diet was quite varied; yet over the course of a day, it may have focused on only a few foods. Because of the seasonal availability of key resources, the same is true of most other nonindustrial cultures.

Second, they have a limited ability to concentrate the reinforcing properties of food. With only the most basic processing methods at their disposal, nonindustrial cultures—and presumably our distant ancestors—are forced by necessity to eat food in a less calorie-dense, less refined, less rewarding state. Most don’t have the ability to add refined starch, sugar, salt, or concentrated fat to their meals. The glutamate they eat comes from cooking meat and bones rather than from crystalline MSG. Added flavors, such as herbs and spices, are limited. Although we can find isolated examples of traditional cultures that use concentrated fats, salt, multiple spices, sugars, or more refined starches, none boasts all the enhancements of the affluent industrial diet.

Third, they use few cooking methods. The cooking methods of nonindustrial cultures are extremely limited by modern standards, with most cultures only using two or three methods. Even in affluent Western cultures, cooking methods were limited by technology until relatively recently. Until the 1820s, most cooking in the United States took place in an open hearth, which is a time- and labor-intensive method that makes complex cooking techniques difficult. Cast-iron wood- or coal-fired stoves replaced open hearth cooking in the 1820s, and they remained the dominant cooking method until they were replaced by gas and electric stoves in the...

Techniques as simple as sautéing and temperature-controlled baking were difficult or impossible to perform in the home pri...

In 1889, Americans spent 93 percent of their food expenditures on food to be eaten at home, and only 7 percent eating out. Today, we spend about half of our food expenditures on food to be eaten at home, and the other half eating out (see figure 17).

soylent essay

To get around the health concerns that surround MSG, companies have developed alternative sources of glutamate that slip under our radar, such as hydrolyzed yeast and soy protein extracts.

Modern food chemists have created or isolated a vast number of seductive flavors that compel us to buy food. Although these usually appear on an ingredient label as the cryptic phrase “artificial flavors” or “natural flavors,” such terms often conceal a carefully engineered suite of dozens of ingredients.

Bread also happens to be the single largest source of salt in the US diet.

The food industry pours a staggering amount of money into food advertising each year. In 2012, the ten largest food and beverage manufacturers alone spent $6.9 billion on food advertising, and fast-food restaurants spent more than $4 billion on top of that. To put that into perspective, the total amount of funding dedicated to obesity research by the National Institutes of Health, the primary funding agency for biomedical research in the United States, was less than $1 billion in 2012. The amount of money and effort put into convincing us to eat far outweighs that put into preventing overeating and its consequences.

“Life is a game of turning energy into kids,” says Herman Pontzer,

The idea of moderation in eating is totally foreign to hunter-gatherers. In fact, Wood, Hill, and Pontzer explain that hunter-gatherer eating habits can be downright gluttonous. Hill recalls some of the enormous meals he observed among the Aché—men eating five pounds of fatty meat each in a sitting, drinking one and a half liters of pure honey, or eating thirty wild oranges similar to the fruit we buy in the grocery store. And it’s not just the Aché. Pontzer adds that the Hadza also drink honey “like a glass of milk.”

“They fully embrace the idea of ‘eat as much pure fat as you can possibly eat,’” explains Wood, adding, “there’s no hint of moderation whatsoever in their drive and motives with eating food.” Hill’s experience with the Aché echoes this: “Quite simply, they eat everything they can get and they don’t seem to have limits.”

this is fascinating. gluttunous opportunities did exist in huntergatherer times, and restraint was never selecter for

In the affluent world, we stalk Froot Loops, buffalo wings, and chicken nuggets rather than fruit, buffalo, and wild fowl. Most of our foods are rich in calories, and the time, effort, and monetary costs involved in acquiring and preparing them have drastically declined. If we apply OFT to this situation, it becomes clear that we’re surrounded by an enormous variety of extremely valuable foods—foods that are an outstanding deal because they deliver a large number of calories and cost very little. Despite the fact that we live in a radically different environment than a hunter-gatherer, our brains are still highly attuned to good deals (have you ever seen how fast free pizza disappears?). Yet while a hunter-gatherer only encounters great deals occasionally, in our world, we encounter them multiple times per day. This leads us to overeat by activating largely nonconscious brain circuits that are constantly looking for a deal.

Grocery stores became common in the 1920s, providing us with the convenience of a single location for all our food shopping needs,

an interesting and unremarked aspect of increased food convenience.

The research of John Salamone, professor of psychology at the University of Connecticut, allows us to refine this idea:

Palmiter’s mice may just be extremely lazy. So lazy, in fact, that even taking a few steps across the cage to eat and drink aren’t worth the effort. How do we know? Because Salamone’s research shows that dopamine plays a key role in motivation. When he reduces dopamine signaling in the ventral striatum of rodents, they become less willing to work for a reward. They choose easy options over hard options, even if the hard option has a much larger payoff and would normally be the better choice. In other words, reducing their dopamine signaling makes them lazy. Palmiter’s mice have no dopamine, making them quite possibly the laziest mice in the world.

finally this guy is getting the credit he deserves in these neuroscience books! i was on the ground floor for this one.

Palmiter’s mice may just be extremely lazy. So lazy, in fact, that even taking a few steps across the cage to eat and drink aren’t worth the effort. How do we know? Because Salamone’s research shows that dopamine plays a key role in motivation. When he reduces dopamine signaling in the ventral striatum of rodents, they become less willing to work for a reward. They choose easy options over hard options, even if the hard option has a much larger payoff and would normally be the better choice. In other words, reducing...

laziness equal dopamine deficient equals too high threshold for new action program.

impulsivity equals delay discounting plus response inhibition. marshmallow test is test of impulsivity.

He had also been impressed by a number of studies suggesting that the human body vigorously resists large, short-term changes in weight brought about by underfeeding or overfeeding. One of the earliest and most influential studies was the Minnesota Starvation Experiment conducted by the prolific nutrition researcher Ancel Keys in the latter years of World War II. The goal was to understand the effects of starvation on the human body and mind. Over the course of six months of semistarvation, thirty-six young male conscientious objectors lost approximately one-quarter of their initial body weight. While this weight loss was no surprise, what happened after their food restriction was lifted is more interesting: Due primarily to a prodigious appetite, their body weights and adiposity rebounded rapidly. As they regained weight, their appetites normalized, and they eventually settled close to their original weights. It seemed as if a powerful internal control system was regulating their appetite and adiposity.

Let’s return to the Minnesota Starvation Experiment for a moment, but this time, let’s focus on the psychological responses that occurred. Over the course of their weight loss, Keys’s subjects developed a remarkable obsession with food. In addition to their inescapable, gnawing hunger, their conversations, thoughts, fantasies, and dreams revolved around food and eating—part of a phenomenon Keys called “semistarvation neurosis.” They became fascinated by recipes and cookbooks, and some even began collecting cooking utensils. Like leptin-deficient adolescents, their mental lives gradually began to revolve around food.

If you’ve never had the experience of fighting your own body’s starvation response, Jeff Friedman provides a helpful analogy: Those who doubt the power of basic drives, however, might note that although one can hold one’s breath, this conscious act is soon overcome by the compulsion to breathe. The feeling of hunger is intense and, if not as potent as the drive to breathe, is probably no less powerful than the drive to drink when one is thirsty. This is the feeling the obese must resist after they have lost a significant amount of weight.

Friedman’s analogy is an important lesson for people who think weight loss is as easy as deciding to eat less and exercise more. The brain was forged in the flames of highly competitive natural selection, and it doesn’t take weight loss lightly. “[The starvation response] is there for preservation,” says Leibel. “Evolutionarily, it has played a very important role in our survival.”

The leptin system defends vigorously against weight loss, but not so vigorously against weight gain. “I have always thought, and continue to believe,” explains Leibel, “that the leptin hormone is really a mechanism for detecting deficiency, not excess.” It’s not designed to constrain body fatness, perhaps because being too fat is rarely a problem in the wild.

The hypothalamus doesn’t care what you look like in a bathing suit next summer, and it doesn’t care about your risk of developing diabetes in ten years. Its job is to keep your energy balance sheet in the black, and it takes that task very seriously because it was essential for survival and reproduction in the time of our distant ancestors. The tools at its disposal, including hunger, increased food reward, and slowing your metabolic rate, are extremely persuasive. When the hypothalamus squares off with the conscious, rational mind, it usually wins in the end.

The set point doesn’t just differ by individual; it can change over time in the same person. Most people in affluent nations gain fat over the course of a lifetime, showing that the set point can move upward, gradually increasing the lower limit of our comfortable weight. This malleability explains how a lean nation like the nineteenth-century United States can become dangerously overweight over the course of a few generations, without a significant change in genetic makeup.

Our body weight isn’t completely determined by our genes. Just like the temperature set point, the adiposity set point responds to the conditions of our lives.

In 2000, Barry Levin, an obesity and diabetes researcher at Rutgers University, published a paper clearly demonstrating this effect in rats. Starting with a genetically diverse strain of rats, he fed them either ordinary rat pellets or a high-calorie palatable diet. On the palatable diet, some of the rats gained weight and fat, while others didn’t. Levin’s team took the rats that had gained weight and restricted their food intake while keeping them on the palatable diet, which caused them to lose weight and fat. So far this is what you might expect, but what they found next is more interesting: When they lifted the calorie restriction, allowing the animals to eat as much as they wanted again, the rats didn’t just resume their gradual upward trajectory of weight gain—they quickly bounced back up to the weight of rats that had been eating an unrestricted palatable diet and gaining weight the entire time. Levin’s findings suggest that there is a certain weight that the lipostat “wants” an animal to maintain, defending it against changes, and that this weight depends both on genetics and on the specific diet the animal is eating.

barry Levin was who ewan got the HFD DIO model from. i would dispute the characterization of the hfd as highly palatable. it is pretty disgusting, atleast in current formulation.

Levin’s team went further, testing the effects of rotating an obesity-susceptible strain of rats between three different diets. The first diet was ordinary rat pellets, the second diet was the same palatable diet as the previous experiment, and the third diet was a highly palatable milkshake-like meal-replacement beverage called Ensure105 (specifically, the chocolate flavor). As expected, the rats began overeating and gaining weight and fat on the palatable diets. In fact, the rats eating Ensure almost doubled in weight over ten weeks—an impressive feat.