We often talk about willpower as if it were a moral muscle: all you have to do is learn to say no, then do it again the next day. But that image may miss the essential point. Refusing a desire is not only about preventing an action. You also have to keep the object of desire out of the center of attention. Repeated for long enough, that operation can become mental work in its own right.

Food restriction offers an especially revealing case. Sarah Berg says she began monitoring her diet at age 11, in a world where products such as fat-free SnackWell’s cookies already promised a socially acceptable way to want less. Her account is personal, not a clinical study. But it describes a precise experience: when hunger becomes chronic, food keeps returning to thought until it blurs a conversation and dissolves the thread of attention.

Restriction does not eliminate desire: it reserves a place for it

That is the paradox. The more we try not to think about eating, the more we have to monitor what we eat, what we could eat, what we just refused and what we will still have to refuse. Deprivation therefore does not necessarily erase the object of desire. On the contrary, it can reserve a constant share of the mental stage for it.

The Minnesota starvation study conducted at the end of the Second World War offers an extreme version. Thirty-six male volunteers, brought close to starvation, suffered severe physical effects, including a 40% slowdown in metabolism. But the mental effects also struck observers: food-related thoughts became intrusive, to the point of occupying almost the entire psychological life of some participants.

This result does not allow experimental starvation to be equated with an ordinary diet. It shows something else, more general: when an essential resource is scarce, the mind does not remain neutral. It reorganizes its priorities around that lack.

A review published in Nutrition Reviews synthesized 33 studies on continuous calorie restriction and fasting in healthy humans. Its very existence reflects a genuine scientific concern: benefits observed in animals for health and longevity are not enough to guarantee the absence of cognitive costs in humans. Restrictive eating disorders also provide worrying signals, even if they cannot be equated with restriction practiced by healthy people.

For women, the issue is not only biological

The female case adds a social layer. Berg argues that many women learn very early to manage their appetite as if managing a potential fault: do not want too much, do not take too much, do not show too clearly that you want. This point goes beyond food. A study of more than 750,000 news articles shows that female politicians receive more coverage about their appearance than male politicians, and that discussing that appearance, even positively, reduces the competence voters attribute to them.

It would be excessive to conclude that aesthetic pressure mechanically produces a measurable cognitive deficit in all women. The work available here does not describe a neuroscientific mechanism specific to women. It does, however, allow a more precise political and psychological question: what does it cost to have to constantly monitor a desire that your environment asks you to make invisible?

The answer may lie in an expression popularized by Sendhil Mullainathan and Eldar Shafir: mental bandwidth. Their theory of scarcity proposes that a major shortage — of food, money, time or relationships — captures part of the mental resources available. This bandwidth includes attention, working memory, executive control, persistence and long-term planning.

Their book Scarcity even proposes a very large cognitive “tax,” potentially reaching one standard deviation of effective intelligence or willpower in some poverty experiments. This figure must be handled with caution: the scarcity framework has been subject to replication attempts that have not all succeeded, and one critical source places only limited confidence in this estimate. The general idea remains interesting; its exact magnitude is much less solid.

The real cost of self-control may be immobilized attention

This is where hunger becomes a useful metaphor. The problem may not simply be that we “lack willpower.” It may be that part of our attention is immobilized by the need to resist.

For money, the parallel is directly embedded in scarcity theory: having too little forces constant recalculation, trade-offs, delays and renunciations. For time, the same logic applies: every minute becomes a decision. For relationships, absence itself can occupy the mind. In all these cases, scarcity is not only an external condition; it becomes a recurring internal object.

Can the same idea be applied to social media, tobacco or procrastination? The work cited here does not demonstrate that. We therefore have to speak of an analogy, not an established scientific result. But the analogy deserves to be tested: when someone spends the day telling themselves “don’t look at your phone,” “don’t smoke,” “don’t put this task off,” they are not merely exercising discipline. They are also keeping in memory precisely what they are trying to avoid.

In other words, some self-control strategies may have a design flaw: they require desire to remain visible in order to be fought.

Resist less, organize better

The practical consequence is not to abandon all limits. It is to reduce the number of limits that have to be mentally renegotiated at every moment.

  • Turn repeated decisions into simple rules. A stable rule may require less attention than a trade-off repeated twenty times in a day.
  • Create margin. If scarcity taxes bandwidth, then “slack” — a little time, money, available food or flexibility — is not just comfort. It may be protection against mental saturation.
  • Change the environment rather than lecture the individual. Moving a temptation away, automating certain decisions or simplifying a path can be more effective than demanding permanent vigilance.
  • Judge failures of self-control cautiously. A person whose attention is already captured by scarcity may have less room to absorb a mistake without sliding into another unfavorable decision.

This logic also applies to public policy. If aid, a form, an obligation or support is designed for people already under constraint, adding choices, tight deadlines and repetitive procedures can consume precisely the mental resource they have least of. This is not a quantified result provided by the cited research, but a reasonable consequence of the scarcity framework: a policy can fail not because its beneficiaries “do not want to,” but because it asks too much attention from them at the wrong moment.

Willpower is not free

Perhaps the most unsettling point is this: our culture readily admires self-mastery without accounting for what it mobilizes. We see the visible refusal — not eating, not spending, not giving in — but not the inner conversation required to maintain that refusal.

Hunger makes this cost impossible to ignore because it concerns a fundamental biological resource. When it takes hold, it can colonize attention. Scarcity theory suggests that other shortages may do something comparable. And women’s social experience reminds us that a person can be pushed to turn this struggle into daily discipline, then be judged on their performance as though that discipline consumed nothing.

Perhaps the question should therefore shift. Instead of constantly asking “why didn’t you resist?”, we should also ask: how much attention had you already spent resisting up to that point? It is a less spectacular way of talking about willpower. But probably a more useful way to design our habits, environments and expectations.