Fact: Most diets don't work.
A survey done by The Council on Size and Weight Discrimination found that 95 percent of folks who went on a diet regained all the weight they lost in one to five years. This might be because success (and weight loss) depends soley on our own self-control. Or it might be the result of previous habits that hard-wire dieters and athletes to crave junk food—regardless of willpower.
New findings suggest the latter is to blame. A recent study in Frontiers of Psychology showed that feeding rats a diet of junk food reduced their appetite for healthier nourishment. Researchers speculated that the same thing could happen in humans, hard-wiring our brains to crave junk in a behavioral, reward-seeking sense. “It's like you've just had ice cream for lunch, yet you still go and eat more when you hear the ice cream van come by,” said Margaret Morris, Ph.D., of UNSW in a press release.
It sounds almost Pavlovian—and it is. But the research has a flip-side, too. If we're teaching our brains to want junk, can't we instead train them to crave healthy food?
Here's how it works. When you’re training for a race, it can be tempting to reward yourself after a hard training day with a high-calorie snack. This creates an association between the training and the reward that’s hard to shake—and before you know it, you’re off racing weight.
“If somebody is stressed, they might have a brownie,” says Susan Roberts, Ph.D., director of the Energy Metabolism Laboratory at the USDA HNRCA and professor at Tufts University. “Then the next time they’re stressed they have another brownie, and sure enough, every time they’re stressed they think about brownies. Our brain is naturally designed to make associations between A and B.”
The trick then is to train our brains to consider healthy food—not junk—as our reward. Roberts recently published a study online in Nutrition & Diabetes that, despite being very small, has been getting a lot press. The study was the fourth in a series focusing on the potential of the “iDiet” (not affiliated with a certain tech giant), a lifestyle approach to weight loss that replaces junk food with high-fiber, high-protein meals that tastes similar to what the dieters used to eat, effectively tricking and re-wiring the reward-seeking part of the brain and conditioning people to prefer healthier foods.
Thirteen overweight participants—eight on the iDiet and five in a control group that wasn’t—underwent MRI brain scans at the beginning and end of a six-month period. During each scan, researchers showed participants pictures of both traditional comfort foods like fried chicken and chocolate, and then healthier, low-calorie foods like salad and grilled chicken.
At the end-period scan, the researchers found that the reward and addiction centers of the participants’ brains had changed. When shown the healthier foods, the iDieters’ neurons fired away in their reward centers; when shown the unhealthy foods, their neural responsiveness was more muted. The researchers concluded that using the iDiet over six months essentially re-wired the participants’ brains to prefer the lower-calories foods.
“It was judged to be a pretty big effect,” says Roberts. “I was expecting this. We previously published that we had these significant changes in reports of cravings that the dieters gave us, but to see it at a brain level was totally cool.”
In essence, what Roberts proved was that attacking hunger through behavioral therapy—not willpower—will have a much more positive effect for dieters and athletes, and through re-wiring and building these healthy habits, people can keep the weight off or stay in performance shape.
So how does the iDiet work? Simple foods swaps.
“If somebody craves an ice cream sundae, what I’d do is I’d say fine, but here’s how I want you to have it: I want you to buy sugar-free ice cream and mix it with a high-fiber cereal,” Roberts says. It tastes good, but won’t spike your blood sugar (which triggers hunger) and it’s full of fiber that slows digestion and fills you up.
Yes, food swaps have been around for a long time to cut calories, but now we know that they can work with our brains to build better eating habits. Swapping out a sundae for one of Roberts’ recipes will fill your craving or reward needs. If you’re an athlete that’s trying to stay in performance shape, simple swaps could help you build better eating habits. For example, swap the sports drink—which can have up to double-digit tablespoons of sugar in it —for water or water and a sodium powder. Your brain will get used to it, and your waistline will thank you.
“Food cravings are really associations between a taste and a rush of calories that you get from that food,” Roberts says. “You still get the taste to enjoy, but you don’t get that dopamine frenzy. The ridiculous thing is, it’s not that hard. It’s surprisingly easy.”
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