BUENOS AIRES — Lux Moreno is an Argentine philosopher, writer and activist of the so-called fat-acceptance movement. In Argentina, it is the Fat Movement (Movimiento Gordo), written this way to appropriate a word that is often used as an insult.

Born in 1986, Moreno has recently published her autobiographical Gorda vanidosa: Sobre la gordura en la era del espectáculo (Fat and Vain: Girth in the Age of Spectacle). She was a fat child who became an anorexic teenager, then an overweight adult until she resorted to gastric bypass surgery on a doctor's advice. "Nobody warns you that bariatric surgery to reduce weight is not magic, but a major intervention," she told Clarín. People are not informed, she says, that "it's not advisable for fertile women, that you could have menstrual bleeding or thrombosis the first month, that you must exercise five days a week. That you have a lifelong contract with taking vitamin and iron pills."

Few reading Gorda Vanidosa will fail to find common ground with Moreno. Who has not felt they had to lose weight at least once in their lives? Or the dread of having to pick a larger size in clothes or the approach of summer, knowing you're overweight? Clearly these fears pertain more to women than men, as their bodies are more likely to be commodified. Amid debates in Argentina on abortion, says Moreno, now "there's a possibility people will stop and question and think about the body they want to have. Or have some idea about the body itself."

It is now a "duty" to be thin.

The fat-acceptance movement first appeared in the late 1960s amid a wider struggle then for the rights of minorities, and had a resurgence in the 1980s and 90s. Today, eight years after the World Health Organization (WHO) declared obesity to be a global epidemic, we may need a new critique of what fatness means. Moreno describes in her book how the obesity epidemic was "fabricated." The first step was to impose the BMI (Body Mass Index, which gauges the relative proportions of body and height) as measuring index. This is "supposedly a universal measurement" that defines one's wellness regardless of "age, ethnicity, geographical origin or any other factor, and justifies all types of interventions," says Moreno. WHO, she adds, has also lowered its BMI limits on weight excess, immediately making half the world's population obese. The BMI has in the past 20 years been the basis of healthcare policies designed to eradicate weight excesses.

Moreno says it is now a "duty" to be thin according to a hegemonic medical model that transfers itself into "judgemental gazes." That then permeates fat people's views of themselves. Being thin is the norm, she says, so being overweight is abnormal. The "presentable" employee or candidate is never fat, she observes, while excess weight is perceived as related to such qualities as weak will power, inefficiency, ugliness. Even the rich and famous will find it hard to escape these social prejudices. She cites the British singer Adele, who has shed weight while ascending to international stardom.

Another group fighting fat persecution locally is AnyBody, which has pressured retailers to stock all sizes in shops. Its slogan was "Beauty Comes in All Sizes," though Moreno points out that Argentine laws on sizing are not being respected. She thinks the retail argument heard about the higher cost of creating clothes for bigger people is really "an excuse."

Moreno adds that surgery is a drastic measure that has overtaken dieting, thanks to the pressures of a "neoliberal world." The message, she says, is "there is no time to lose. "I don't have three years to diet and lose weight, I have to lose it now"."

In the Platonic tradition, she says, beauty is "unattainable... it is the ideal. Beauty is what is good and real." But today, she observes, beauty has become "a source of pain and illness: it is the dangling carrot we are all chasing."