Opinion | Diet Culture Is Unhealthy. It’s Also Immoral.

Such examples proliferate in philosophy too: The standard example of the much-studied phenomenon of akrasia, weakness of the will, is succumbing to a cookie. The natural human appetite for rich and sugary foods is thereby derided as not only contrary to reason but also something to be tamed, shunned, even shamed. The constant deprivation and, sometimes, sheer hunger of someone who sticks to a rigorous diet is envisaged as an unambiguously good thing and as an achievement, even a virtue.

Is it, though? As someone who recently dieted with some success (“success”), it is obvious to me that I’ve set a bad example for my now 2-year-old daughter — one that will only become more problematic over time, as she becomes more and more aware of what I am or am not eating. I have contributed in a small way to a society that lauds certain bodies and derogates others for more or less arbitrary reasons and ones that lead to a great deal of cruelty and suffering. (The most common basis for childhood bullying is a child’s weight.) I have denied myself pleasure and caused myself the gnawing pain and sapping anxiety of hunger.

These are all things we usually think of as straightforward ethical ills. Almost all versions of the family of moral theories known as consequentialism hold that pleasure is morally good and pain and suffering are morally bad. Even if this is not the whole truth of ethics, it is plausibly part of the truth.

And it has the superficially surprising implication that dieting inflicts real moral costs, real moral harms, ones we largely impose on ourselves (albeit under the influence of potent social forces). If the chances of long-term weight loss (and the supposed benefits and pleasures that conveys) are vanishingly small, then why do we keep doing it? I suspect the answer is not only habit and a false sense of obligation but also the lure of aspiration: a dieter’s perpetual sense of getting somewhere, getting smaller and thus becoming more acceptable, more reasonable, as a body.

But while philosophy in its current form may fetishize thinness, it also has within it the power to challenge these ideas and even to reconfigure our moral relationship to them entirely.

We are at a moment during the year when many people will try, and even regard themselves as duty bound, to go on a diet. But if dieting is a practice that causes a great deal of harm — in the form of pain, suffering, anxiety and sheer hunger — and rarely works to deliver the health or happiness it has long advertised, then it is a morally bad practice. It is plausibly not only permissible but obligatory for individuals to divest from it, to condemn it and not to teach it to our children, either explicitly or by example.

Instead, we might strive within ourselves to meet new and better “liberating duties,” to borrow a notion from Joseph Raz. In this case, the duty — for those of us fortunate enough to have the resources — is simply, or not so simply, to eat when we are hungry.