A different approach, which has not been tried, would be to use transcranial magnetic stimulation to temporarily enhance the activity of regions of the brain near the skull. This technique -- in which magnetic fields generate small electrical currents, activating cells in a specified part of the brain -- is being explored for depression patients who don't respond to medication.
A 2010 Nature Neuroscience study used transcranial magnetic stimulation to temporarily inhibit the dorsal lateral prefrontal cortex, and showed that this led to participants making more impatient decisions.
Theoretically, this technology could be applied in the opposite way -- to train relevant brain circuitry to come online during problematic food choices among dieters, so that eventually the person's brain would respond naturally in this way, Hare said.
"If there's enough success with this in conditions such as depression, then I could see that that would be the logical next step," Hare said.
Scientists may also be able to develop behavioral interventions based on brain research -- i.e. how to train and promote self-control. Psychologists, for example, may be able to derive behavioral therapies from the "brain circuit differences that we see in people with different kinds of self control problems," said Joshua Buckholtz, assistant professor of psychology at Harvard University.
Buckholtz has unpublished research suggesting that people with high BMIs and non-obese impulsive people have similar brain chemistry patterns.
Committing to change
To recap: We're bad at self control. Scientists are looking at the brain to figure out how self control breaks down at the neurological level. Such insights could directly lead to interventions in the form of pharmaceuticals or brain stimulation.
In the meantime, what can we do to help ourselves behave more in line with our good intentions, even in the face of temptations?
"The more we recognize the commonality of this problem, the more prepared we'll be to develop solutions to solve a problem, because the solutions end up being the same across all the different domains," Laibson said.
The basis of nonpharmaceutical solutions is the big C-word: commitment. To some extent, most of us are already entrenched in a system of commitments that keep us in line. It's called the workplace.
Journalists publish articles, cashiers scan groceries and teachers grade papers because of systems built into our society that commits them to perform certain tasks, with the threat of punishment -- or not getting paid -- looming over their heads, Laibson said. Managerial structures ensure that employees at every level do what they're supposed to be doing.
"We built this system that is actually well tuned to who we are psychologically," he said. "We're not relying completely on our willpower to do everything. We are letting the system take care of us."
When it comes to money, for instance, many companies offer savings plans that automatically place a fixed percentage of your paycheck into a 401(k) account, with strict penalties if you try to access that money before retirement. Once you sign up, you don't have to think about making the choice every week; it just happens in the background.
"We don't want people to tell us what to do so that we have no freedom, but we do need a little bit of help so that we actually get to work and have a productive day instead of rolling in at 11 a.m.," Laibson said.
Applying that method to food is a lot trickier. Your boss can make you go to a 9 a.m. meeting, but you don't have a Food Manager who prods you to avoid potato chips and count calories at every single meal. Even if your workplace's cafeteria has reasonably sized portions, including small desserts, no one will stop you from buying two or three cookies.
To encourage healthy habits in an already structured workplace, companies could instead institute standing desks and hold standing or even "walking meetings," in which people move around while they discuss business instead of sit in a conference room. These interventions should, however, be tested scientifically before being widely promoted, Laibson said.
Government intervention is another way that self control could be imposed, but a controversial one. The city of New York tried to limit sugary drinks sold to 16 ounces each last year, but an appeals court ruled in July that this was "arbitrary and capricious." In Laibson's view, such a policy needs scientific evidence that it has positive health outcomes before being broadly enacted.
But you don't necessarily need a boss or government official threatening to punish you for breaking rules you already want to follow for the sake of your health. You can set up a system in which you discipline yourself.
Through the Internet, you can wager your own money to commit yourself to your own diet and exercise aspirations. A website called StickK allows you to put your own money on the line in support of whatever goal you may have; if you don't fulfill it, you lose the money. As Yale economist Dean Karlan, co-founder of StickK, told CNN in 2008, "It's a contract to make slothfulness more expensive."
So, think how much money your health-conscious self would offer your sweet-tooth self to keep the ice cream in the freezer, or not buy it at all.
Change can start today.