A new book on willpower asserts that it's a muscle. That is, you can strengthen it with practice, and you can exhaust it with stress and overuse. This makes sense, and years of research back the idea.
For those trying to eat differently — to lose weight or simply to choose more wisely — the strength of this muscle can determine whether change occurs or not. As with physical exercise, many of us struggle to start and stick with it. However, even those who can flex the muscle in other situations can find it too weak to budge when it comes to food.
So, if self-control's a muscle, why can't you exercise it here, too?
The book Willpower: Rediscovering the Greatest Human Strength, by Roy F. Baumeister and John Tierney, draws on Baumeister's work on self-control. The benefits of self-control have been documented for decades. And studies have established that practice indeed bolsters self-control (even if people vary genetically in that trait).
Baumeister's work goes farther, finding that self-control can fizzle out — when people's minds are taxed and fatigued, when they've been struggling at self-control for too long a stretch at once. Here is more solid evidence against restrictive dieting. And here is support for the idea that small, persistent efforts will become habits. That's all good news, and helpful for those working to lose weight.
It can be hard to see, though, how this applies to those who say "It feels like a force comes over me," as they head for the ice cream. Or, "I just wasn't thinking," as they pull into KFC. "I knew I was doing it but didn't care," as they attack the brownies. And what's going on when a person's done well for months, then suddenly finds herself slipping into old ways, regaining every lost pound? These are the stories of many, maybe most, overeaters.
Eating habits bring extra challenges to self-control muscle-building. For starters, "you can quit smoking or drinking altogether, but you always have to eat," as many of my clients will say. In other words, eating itself stimulates the desire to eat more. Once you're used to eating certain amounts, you'll be hungry 'til you get there, and hunger is a powerful driver.
If eating a lot increases hunger, once you're used to eating certain foods, they will urge you on to more. Once you've gotten used to foods "engineered to be hyperpalatable,"* you will want more and more of them. Some of us experience a drive for them that's as strong as an addict's drive drugs. This includes most junk foods, fast foods, many canned or packaged supermarket foods, and chain restaurant food. These highly hard-to-control foods surround us. It's as if we've got to do twice the work — or even more — to build the same muscle that would ordinarily bulk up with practice.