The End of Craving: Recovering the Lost Wisdom of Eating Well – Mark Schatzker

Thoughts: The End of Craving is incisive and convincingly argued. My main takeaway: in most areas of life, listening to your body and doing what feels good means doing what’s good for you. In order to allow your body to provide this accurate feedback, try to avoid situations that have been engineered to make a thing appear to be different than what it is, or engineered to make it especially pleasurable/rewarding (in the context of the book, this means food with artificial additives).

Summary: In The End of Craving, Mark Schatzker argues that food additives—including artificial sweeteners, artificial flavours, substances that modify the texture of food, and vitamins—are preventing humans’ from being able to accurately evaluate a food’s nutritional content based on its taste. For much of humans’ evolutionary past, a food’s flavour used to be a reliable indicator of its nutritional content, so if a person ate what tasted good to them in the amount they wanted, they would get all the nutrients they needed and remain in good health. But today’s foods are increasingly being engineered to deceive the tongue, making a food taste like it contains more sugar than it actually does, or making a mixture of plant-derived ingredients seem to be meat. Faced with such an uncertain and deceptive food environment, humans have responded by seeking to consume more food than necessary.

(The notes below are not a summary of the book, but rather raw notes - whatever I thought, at the time, might be worth remembering.)

Schatzker, Mark. 2021. The End of Craving: Recovering the Lost Wisdom of Eating Well. Avid Reader.

Introduction: The Mystery

Part I: One Disease, Two Cures

1. The New Road to Better Nutrition

2. The Old Italian Way

Part II: You are a Metabolic Genius (and You Love It)

3. You’re Hot. Then You’re Not

• 40: Michel Cabanac’s studies of temperature preferences found that people enjoyed putting their hands in water that brought their body temperature close to a set point. “When it came to body temperature, what felt good was healthy.” (Whereas previous studies of temperature preferences [for a person putting their hand in vessels of water of varying temperatures], all conducted in room-temperature rooms, found people’s ideal temperature was consistent, and about room-temperature.)
• 45: “The inflexibility of the human brain about body weight [i.e. the brain’s tendency to induce behavior that causes body weight to move toward a relatively fixed set point] has been known for at least half a century”
• 50: “The brain doesn’t just resist losing weight. It resists gaining weight…. When weight dips below a certain point, the brain goes into starvation mode and fights like hell to get it back up. But if it rises above set point, the brain also fights—like hell, in some cases—to bring weight back down. It goes against our most deep-seated beliefs about our fraught relationship with food—that fatness is the body’s true aim.”

4. The Quest for Pleasure

• 61: The experience of feeling good “is how the brain achieves its goals. ¶ Michel Cabanac called it the quest for pleasure. Humans are on an eternal quest to maximize feeling good and minimize feeling bad…. Pleasure, simply, is what makes us do things.”
• 63: “The problem with pleasure was that it could not be measured…. ¶ So the behaviorists replaced ‘feelings,’ which could not be measured, with ‘drives,’ which could. Take the phenomenon of thirst as an example. A scientist could measure thirst in a rat by counting the minutes since it last had water, or measuring the concentration of salt in its blood. A scientist could measure the effect of thirst on a rat—how many blocks it would climb to reach its bowl, or how much water it would drink. The concept of ‘thirst’ not only explained both the cause and the effect, it let you predict what a rat would do under certain conditions. Thirst, therefore, was nothing more than the ‘drive’ to make a painful state of needing water go away.”
• “That’s all the word pleasure meant to a behaviorist—a kind of confused term for unpleasantness going away. Sex ‘feels good’ because it makes the persistent drive for sex go away. Food ‘tastes delicious’ because it makes hunger, which you can measure and which is another form of pain, go away.” This theory is known as “drive reduction theory”.

5. Too Much of a Good Thing

• 73-74: Schatzer (after Kent Berridge) draws a distinction between “wanting” and “liking”.
  • Wanting is dopamine-driven - motivation, craving, desire.
  • Liking is distinct from wanting - Schatzer describes it as “the impact moment of pleasure…, payoff…, enjoyment”
  • though the two systems are closely linked in the brain, it’s quite possible to want something you don’t end up liking, and to like something you didn’t want.

Part III: Nutritive Mismatch

6. How Sweet It Is

• 86: “The brain doesn’t just keep tabs on how much sugar enters the mouth or how much sugar winds up in the stomach. It even keeps track of what happens to the sugar. In another… experiment…, [Ivan de] Araujo gave mice a drug that blocked sugar from being turned into energy. The mice tasted the sugar and it was sensed in the stomach, but if it couldn’t be used as fuel, sugar it [sic] lost its magnetic pull. What the brain ultimately cares about isn’t how food tastes. It cares about whether food is useful.”
• 89: study by Dana Small, which gave people different drinks that were uniformly sweet but contained more, as many, or fewer calories than would be expected if the drinks’ sweetness came only from sugar: “over time, a distinct pattern had emerged: when people consumed the drinks in which the sweetness and calories were not in sync, the calories those drinks delivered would not be properly metabolized.”
  • 90: This phenomenon is known as “nutritive mismatch”
  • Small’s research revealed that “sweetness wasn’t just an enjoyable taste sensation. It was a metabolic signal, the first spark in a string of biochemical processes by which sugar is turned into energy.”
• 95: “Ever since organisms began sensing food as it entered their body, the information gathered was reliable. This is why the ability evolved in the first place…. ¶ This system, as we have seen, is designed for accuracy. But it evolved in an environment in which food provided the senses with accurate information. Dana Small’s research shows what happens when that changes—when the food we eat tells the brain a nutritional lie. The system fails.”

7. Not Losing Isn’t Everything, It’s the Only Thing

• Summary: people/organisms are much more motivated to avoid a loss than to achieve a gain. Uncertainty turns up motivation because people want to not miss out on an uncertain reward.
• 110: “Uncertainty… is so universally enthralling that we set up organized bouts of it. We create rules. We buy tickets and congregate by the thousands so that we may all sit and experience a roller-coaster of edge-of-your-seat risk. We call these events games. We may think games are about winning and losing, but those are just outcomes. Games are driven by the excitement of not knowing what’s going to happen next.” - Reminds me of discussions I had years ago with a singer, wondering why people didn’t patronize artistic events in the same way they did sporting events. How could uncertainty be incorporated into artistic performances? Would this even be desirable?
• 113: the “insurance hypothesis of obesity”: food insecurity is a much stronger prediction of obesity than poverty is. Food insecurity leads to obesity in much the same way that uncertainty leads to loss aversion.

8. Creamfibre 7000

• 120: uncertainty activates the dopamine-driven “wanting” system. “And fake sweetness is one way to create uncertainty”
• 130: “The thing that changed—the event that energized ‘wanting’ and created this artificial, inescapable hunger that has ensnared so many of us—is nutritive mismatch. For the first time in the history of our species, the information the brain senses about food has become consistently unreliable. ¶ The food environment is now something like a calorie casino. The threat of losses makes people behave in self-destructive ways. We are not born to be fat. The problem is we are being goaded into a game we cannot resist. And it is killing us.” (emph. mine)

Part IV: The Help That Hurts

9. Why Does Food Taste Good, Anyways?

• 141-142: “Brain imaging, however, shows there is a way to generate an even bigger eruption of ‘liking.’ Instead of simply following through with what is expected, ‘violate’ expectations. Don’t deliver what the listener thinks is coming. Catch them off guard with something even better, something amazing they didn’t expect—a sweet yet aching harmony, or a sudden change of key. The unexpectedness of it jerks us to attention. The physical response—goosebumps and chills—is similar to a fear response. The brain realizes something is amiss. But when the brain identifies that this unexpected thing is a good thing, the opposite of a loss, we are upgraded to a higher tier of pleasure. We are left feeling moved, cleansed, purged, and reborn. Music can tear you to shreds and stitch you back together better than new. ¶ In this we find a clue to the purpose of ‘liking.’ It is, simply, quality control. It tells us if what the system got is bad, good, or better than expected.”
• 142-143: “instead of eating one thing, [omnivores] eat a lot of things…. This is the category we humans fit into. An omnivore gets it all—calories, proteins, vitamins, minerals—from many different foods. This seems like a brutal if not impossible undertaking. No single food contains all the necessary nutrients we require to live. Different foods, furthermore, contain different nutrients in different amounts. And some foods are poisonous. To make things even more convoluted, the omnivore’s needs are an up-and-down jumble—children require more energy per pound of body weight than adults, who themselves have a higher vitamin requirement. Pregnancy throws everything for a loop. ¶ The great food psychologist Paul Rozin called this predicament ‘the omnivore’s dilemma.’ (The famous book by Michael Pollan would come much later.) How did we solve it? With ‘liking.’ The mouth tells us what the eyes can’t: how sweet, how rich, how salty, how starchy, if it’s poisonous, and so forth. You can’t tell how good a peach is by looking at it. But you can by biting into it. If it’s bad, we spit it out. If it’s good, we keep eating. If it’s exceptional, we become lost in its spell.”

10. You Are Eating Pig Feed

• 159: B vitamins are necessary for processing nutrients the body can use as energy. Thus, an excess of calories don’t lead to weight gain in the absence of an excess of B vitamins, while an excess of B vitamins and an excess of calories can lead to obesity.

Part V: The Brain-Changing Power of Good Food

11. The End of Craving

12. Can This Be Fixed?

• 181: “So here, then, is the theory spelled out: the obesity epidemic is being fuelled by advancements in food technology that have disrupted the brain’s ability to sense nutrients, altered eating behavior, and given food an unnatural energetic potency. This is not an all-encompassing theory that claims to explain each and every instance of overweight or obesity. But it is the change.”

13. A Visit to the Old Road