Health & wellness


Understanding your willpower


Every other Tuesday, the doctors and nurses in my practice meet over lunch to hear a specialist speak about recent developments in medicine. The subjects vary — recently we’ve learned about eye diseases, domestic violence, and new anticoagulant medications — but the menu never does. There are always three platters: sandwiches, fresh fruit, and cookies. Speaking just for myself, though I don’t think I’m alone in this, the cookies are a problem.

Here’s what happens: I rush to the conference room after seeing patients for four hours straight without a break. I’m tired and I’m hungry. I start off with a sandwich — something sensible, like turkey on whole wheat or a veggie wrap. Then, for the next 50 minutes I alternate between listening to the speaker and thinking about whether to have some fruit or dig in to the cookies: chocolate-chocolate chunk, oatmeal raisin, macadamia . . . oh, they’re good; sweet and salty and buttery, and big, probably 300 calories apiece — 300 calories that I don’t need.

Sometimes I succumb and have one of the cookies. Occasionally I have (gasp) two. But often I have none, and then I go back to work feeling light and virtuous, having conquered the demon.


I wish I knew what allows me to resist those cookies when I do. I’d bottle it and offer it to my patients (and keep a little for myself). I provide patients with information about nutrition, exercise, and other aspects of a healthy lifestyle routinely but, the truth is, it’s usually not information they lack. It’s the ability to choose, consistently, the healthier option over the tempting but less healthy option — the gym over the couch, or the fruit over the cookies. In other words, as they so often tell me, what my patients need is more willpower.

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Take Martha, a patient of mine in her 40s. She’s a smart, accomplished woman who juggles a family and a demanding job. The one thing she can’t seem to accomplish, though, is losing weight. Martha admits that she finds it nearly impossible to resist the fattening foods that prevent her from shedding excess pounds. “I have no willpower,’’ she says.

Yet every weekday for the past several years, Martha has woken up before her husband and kids and gone to an outdoor “boot camp’’ exercise class. Would you say that a woman who’s raising a family and succeeding in her career, not to mention one who routinely drags herself out of a warm bed on dark, cold mornings to do squats and lunges, has no willpower?

After reading “Willpower: Rediscovering the Greatest Human Strength,’’ a book by psychologist Roy F. Baumeister and science journalist John Tierney, published this fall, I wonder if I’ve been thinking about this all wrong. The authors argue that willpower isn’t something you have or don’t have — or, as in Martha’s case, something you have in one sphere and lack in another. Neither is it moral virtue or mental fortitude, as philosophers, theologians, and psychologists through the ages have conceived of it. Rather, say Baumeister and Tierney, willpower is a normal human brain capacity that can be strengthened or tired out like a muscle, and that requires adequate glucose to function properly.

It makes sense, from an evolutionary perspective, that humans acquired the ability to defer gratification, persist in difficult or tedious tasks, and resist appealing but dangerous behaviors — all forms of willpower. Our primitive ancestors were, no doubt, more likely to survive if they could wait for berries to ripen before eating them, stand guard for hours over a campsite, and keep their hands off their neighbors’ mates.


In the 1960s, a famous experiment in which 4-year-olds were given the choice between eating one marshmallow right away or two marshmallows 15 minutes later suggested that, in modern times, willpower still confers certain advantages: The kids who held out for the larger treat grew up to be more popular, earned higher SAT scores and bigger salaries, and were less likely to be obese or abuse drugs.

Baumeister and Tierney point out that while some people — those very patient 4-year-olds, for example — have more innate willpower than others, willpower can be increased with repeated use. In one experiment, a group of college students instructed to focus on standing up straighter for two weeks did better on tests requiring persistence and self-discipline than peers who had not worked on improving their posture.

Willpower, though, is not only a skill that can be sharpened, but also a commodity that can be depleted. Many studies have shown that when people try for too long and too intensely to control themselves, or control themselves in too many different ways at once (quitting smoking and dieting at the same time, for example) their willpower tends to wane. This is particularly true when blood sugar levels are low.

Dieters — or a doctor sitting in front of a cookie platter after a busy morning’s work — face what Baumeister and Tierney call “the perfect storm’’ of willpower challenge. By perpetually resisting food we’ve told ourselves we can’t have, we’re depleting our willpower — and increasing our craving for the sugar that fuels our brain’s willpower efforts. It’s no coincidence that when we break our diets we’re more likely to reach for chocolate than equally caloric prime rib.

The situation isn’t hopeless, though. Forgoing overly restrictive diets, planning occasional indulgences, stabilizing blood sugar levels by eating frequent small meals, limiting quickly metabolized refined sugar and flour, and avoiding exhaustion and excess stress all help maintain our willpower stores and make it easier not to overeat.


These ideas about willpower have not gone unchallenged. Soon after the publication of Baumeister and Tierney’s book, two Stanford psychologists wrote an editorial in The New York Times arguing that willpower is less about brain activity and glucose and more about belief. Their research supports the idea that people have willpower when they think they do. This may be so. All I can tell you, as you pack up the holiday decorations and start writing lists of resolutions, is that on Tuesdays when I’ve had a good breakfast and a mid-morning snack, and especially when my workload is a bit lighter, those cookies don’t seem quite as irresistible.

Dr. Suzanne Koven is a primary care internist at Massachusetts General Hospital. She writes a monthly column about the uncertainties, dilemmas, and stories that patients and doctors share in practice. Read her blog on She can be reached at