Sometimes it feels like all you do during adulthood is accumulate pounds and passwords. Inflation is so bad right now that quarters cost 50 cents but that’s not the only thing that’s inflating. Many of us have gained the COVID-19 pounds.
In 1960, one in seven US adults was obese. By 2010, that reached one in three. And childhood obesity has quintupled. We can contrive all sorts of unscientific voluptuous rationalizations for why this has occurred but the science is very simple and very clear: we ate more.
Yes, it’s a matter of energy balance: calories in vs calories out. Some people will take time away from building their perpetual motion machines to argue with me about this but it’s basic physics. (And if not we need to urgently revise the laws of thermodynamics.) More of you isn’t spontaneously created. The pounds come from somewhere and, no, it’s not dark matter.
So what’s key problem that nobody talks about? Your brain. Why the brain? Because that’s where the bad decisions come from. Some will yell it’s their genetics but the obesity epidemic didn’t start until 1978 and genetics don’t change that fast. Yes, genes are an issue but they only load the gun – behavior pulls the trigger. And wanna guess what part of the body those obesity genes affect?
From The Hungry Brain:
Although some genes relate to other processes such as fat metabolism, the lion’s share exert their influence in the brain, and of those, many act via brain circuits that are already known to regulate food intake and adiposity (such as POMC neurons and their downstream targets). This suggests that genetic differences in brain function are the primary reason why some people are fatter than others.
And all of this is a very serious issue because nearly one-third of deaths among older US adults are due to excess weight. This topic requires us to be on our best epistemic behavior. So where are we gonna get our information from?
Stephan J. Guyenet is an obesity researcher with a Ph.D. in neurobiology from the University of Washington. His excellent book is The Hungry Brain: Outsmarting the Instincts That Make Us Overeat.
Let’s get to it…
In the early 1990s, researcher Eric Ravussin locked subjects in a metabolic ward with vending machines filled with the most tempting of foods. Cheesecake, Doritos, pudding, etc. And he measured everything they ate.
They could have eaten enough to satisfy their hunger and nothing more – but, of course, they didn’t. Their caloric intake nearly doubled. Over the 7-day study they gained an average of five pounds each.
“When there is tasty food, people eat more.” Yes, that’s hardly surprising. But this started researchers down the road to understanding the real science of eating and how the brain is involved.
A big part of it was dopamine signaling. No, dopamine isn’t “the pleasure molecule.” It’s more about learning and reward. “Caloric density” was particularly rewarding. More calories for the same amount of chewing? Brain says “Me like. Do it again.” Carbs and fat are not mystically awful substances – but they are very rewarding. (French fries, anyone?)
When dopamine signaling reaches a certain level you increase learning dramatically to the point where something becomes habitual. We have a name for this: addiction. Addiction has a terrifying sound to it, but it’s just the point where something learned is so powerful it can overwhelm constructive behavior. Technology and experimentation have allowed us to create “supernormal stimuli”, food far more rewarding that anything our basic programming is ready for.
So we’re screwed? No, but the answer lies in research that has been around a very long time, that the diet industry never discusses… and that you are really, really not going to like.
In 1965 scientists did what was pretty much the opposite of the vending machine study. Locked people up and gave them nothing but a bland liquid diet. Had all the nutrients and calories you need but tasted meh. They could eat as much as they wanted…
So, of course, they didn’t. Lean subjects’ weight stayed stable. The obese subjects lost fat like they had a wasting disease. But here’s the interesting part…
There was no “starvation response.” They weren’t hungry. They didn’t feel deprived. And their weight resisted any notion of that “set point” we hear so much about. Their bodies didn’t fight to get back to a previous overweight condition. Yeah, you can see where this is going…
Weight loss is often less about genetics, or magic “evil” foods and more about when it tastes really good, we eat too much of it.
The answer? Eat simpler food. Somewhat blander food. Yes, I know what some of you just heard was “deprive yourself of all happiness on earth” but what I said was “eat blander food.” Not “flavorless” bland but “apples instead of chocolate cake” bland. I understand that this might be more depressing than a playlist of nothing but country-western songs and The Smiths but it makes intuitive sense. Some might say it’s obvious, but given the tsunami waves of misinformation we get about nutrition these days, “obvious” could use a lobbying group right now.
Guyenet writes: “There are many ways to lose weight, but all else being equal, a diet that’s lower in reward value will control appetite and reduce adiposity more effectively than one that’s high in reward value.”
Sometimes you want something to snack on but there’s nothing good in the fridge, so you don’t eat anything. What’s that tell you about your “hunger”?
Next time you’re “hungry”, ask yourself: “Would I eat broccoli?” If not, you’re probably not really hungry. This will make you a leaner person. No, I didn’t say happier. I said, “leaner.”
And eating simpler, less rewarding foods means less struggle. Michel Cabanac, a physiology researcher at Laval University, replicated the bland liquid diet study and found his subjects “were always in good spirits.” Meanwhile his control group that ate reduced portions of their normal diet were always hungry. Not because they were starving but because their brain was like Animal from The Muppets shouting, “ME WANT MORE TASTY!”
I know, this is not what you want to hear — that’s how you know it’s true. (And now that half of my mailing list has unsubscribed, it’s a lot less crowded in here. Feel free to stretch out.)
Some people are thinking: “Eat less super tasty food? Over my dead body.”
Given the health consequences of obesity, well, that’s not outside the realm of possibility…
(To learn more about how to improve your relationships, check out my new bestselling book here.)
Okay, take a second to scream into a cushion. Done? Good. I realize this post may be the feel-bad hit of the summer but I promise this next tip won’t make you hate me…
As much as the previous one did.
In 2010 Chris Voight ate nothing but 20 plain potatoes a day for 60 days. Yes, your mind cannot process that degree of horror. He lost 21 pounds. Frankly, he had trouble eating enough because he just wasn’t all that hungry.
Yes, this brief tableau of gastronomic desolation is anecdotal, but the scientists are nodding. Food variety is a very big deal. What six words have the mystical ability to increase space in your stomach? “Do you have room for dessert?”
Even within a meal we go back and forth between steak and potatoes or chips and soda. Why? Keeps the variety high. When variety is low, we get tired of whatever we’re eating faster. Researchers have even coined the term “the buffet effect” because the endless options resist any habituation and people eat until they’re ready to explode. (Example: Thanksgiving.)
More options mean more eating. Less variety is an easy way to feel full on fewer calories.
Now I don’t mean to distract you from the noose you’ve been tying but there are other methods we can use to be better about eating. And they don’t require obvious deprivation.
Because it’s all about making the deprivation less obvious…
Between 1929 and 2012 food got dramatically cheaper. It went from costing 23% of disposable income to 10%. You didn’t have to take days to hunt down a gazelle; you could have pizza delivered to your door. If you had to walk 6 miles to shoot a Pop-Tart with a bow and arrow, you’d think twice.
A part of your brain called the OFC (orbitofrontal cortex) calculates how much effort it will take to get food, how much energy it contains and whether the deal is worth it, like a little economist in your gray matter. And it’s very good at its job. Problem is, these days the rewards are so high and the effort so low that it always comes up in the black.
So control your environment. Make tastier food harder to get. The biggest step here is discipline at the grocery store. Don’t let it in the house and it doesn’t get eaten. Yes, your family might complain at first but do the right thing. Be a good dad. Win a wife-time achievement award.
Buy more food that requires preparation and you’ll make less of it. Put that candy where it’s not visible. Don’t make it easy to snack. Peeling each orange or taking every pistachio out of its shell is a lot harder than shoveling M+M’s in your face. Your OFC will notice the effort isn’t worth it.
Allan Bloom once said, “Your soul is a mirror of what is around you.”
Your waistline is too.
Alright, as we continue this post that was specifically designed for your disenchantment, the inevitable question comes up about what to eat. Specifically, what food helps you eat less food?
We need to understand the neurobiological and hormonal underpinnings of leptin signaling and how ventromedial hypothalamic nucleus regulation affects…
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The important thing to remember is that the brain has a thermostat to regulate eating. Some foods contain more of the cues that tell your gray matter to send the “full” signal. And you are really not going to like this next part…
More tasty = less satiating. Yes, it sucks. Higher caloric density is not only more rewarding, but because it’s dense it doesn’t take up as much room in your belly. And your gut has “mechanosensors” that detect stomach distension. So you’re taking in a ton of calories, your brain is saying “GOOD. MORE.” And your stomach is saying, “Plenty of room in here. Go ahead.”
So other than eating less calorically dense food, what should you do? First, eat more protein. The success of most low-carb diets is less about the reduction of carbohydrates and more about the increase in protein. And eat more fiber. Researcher Susanna Holt found the more fiber people ate, the more filling the meal was.
Beans, lentils, vegetables, oatmeal, avocados, yogurt, and eggs are all high satiety. Fruit, steak and fish were some of the most satiating foods tested. And plain potatoes were number one.
On the other hand, bakery products like cake, croissants, and doughnuts are a slow-motion car crash. They had the lowest satiety scores of anything tested.
We’ve covered the calories-in part of the energy balance equation. What about calories-out? How does exercise fit in here?
You may have heard that exercise doesn’t help you lose weight. That’s true…
Sometimes. John Blundell, professor of psychobiology at the University of Leeds, did a twelve-week study where he put people on an exercise program and they lost an average of more than eight pounds of fat. But that’s an average. Changes in adiposity varied from a reduction of twenty-one pounds to an increase of six pounds.
Simply put: exercise makes some folks more hungry and others not. In general, people are going to see better results from controlling intake vs increasing exercise. (Not to mention that unless you’re a professional athlete, the amount you eat can always outstrip the number of hours you can put in at the gym.)
That said, the research is very consistent on exercise helping you maintain weight loss. It seems to help lean people resist fat gain in the face of overeating. Yes, the music at the gym is even worse than the music at the dentist’s office but go anyway. (We must accept that places which are good for your health but occasionally cause pain all seem to have bad music.)
Okay, let’s round it all up – and learn the final tip to help you stay in shape. And this one is actually fun…
Here’s the neuroscience of eating less and staying fit:
Okay, so after a few thousand words that have inspired you to commit untold thought crimes against me, what’s the weight loss secret that is fun and easy?
Rest. Sleep doesn’t get enough credit. According to researchers, it’s as vital to good health as eating right, hitting the gym and not being thrown from a moving car.
Studies show people who get less than seven hours of sleep a night tend to gain weight. Why? Your brain responds to feeling tired by saying, “Hmm, we need more energy – LET’S EAT!” And, as all cranky, sleep-deprived people know, not getting enough rest monkeys with your emotions. This makes us specifically more interested in calorically dense, low satiety, high reward food. Why? They make you feel better emotionally.
So get more sleep. And do things to reduce stress that don’t involve your stomach, like exercise or seeing friends. (And if you really need something sweet, go for a diet beverage. Research shows it’s the sweet taste we need to reduce stress – not the calories.)
Hunter-gatherer groups today have the same genes we do. But they don’t experience obesity, they don’t gain weight with age, and their rates of high blood pressure and type-2 diabetes are negligible. Their secrets? Limited food variety. Food that’s less calorically dense and comparatively bland. They get more protein and fiber. Acquiring and preparing food takes more effort. They exercise and rest more.
They have other ways to enjoy life. Like friends and family. That is the spiritual corn syrup we should be adding to everything.
But now I fear that all this talk of food might be making you hungry…
And so I ask: Would you eat broccoli?