How Two Historic Health Myths Shaped Today's Obesity Crisis — and How We Can Fix It
In science and medicine, the most dramatic explanations often grab headlines – but they can sometimes be wrong. Two classic examples are the mid-20th-century diet-heart hypothesis and early psychoanalytic theory. In the 1950s–60s, researchers convinced the world that saturated fat was the villain behind heart disease, leading governments and food makers to push low-fat diets. Meanwhile, Sigmund Freud's psychoanalysis – with its emphasis on childhood trauma and unconscious drives – dominated psychology, sidelining Alfred Adler's more future-oriented ideas.
The Fat Fallacy: Keys, Low-Fat Diets, and the Obesity Surge
In the post-war era, heart disease was skyrocketing. A 1951 survey called body fat "America's 'primary public health problem'." In 1952 President Eisenhower's heart attack made heart disease a national crisis. Nutritionists scrambled to explain why. In 1958 Ancel Keys launched his famous Seven Countries Study and emerged as the loudest voice blaming saturated fat.
Keys famously concluded that "fat was to blame" for heart disease and that only a low-fat diet would reverse the trend. By the 1960s–70s, the idea "fat = bad" had won the day: public health guidelines and doctors told everyone to slash butter, eggs and meat fat out of their diets. The food industry rushed to replace fat with cheap carbs; low-fat products were sweetened heavily with sugar to taste good.
Over the same decades, obesity and related diseases exploded. US obesity rates more than tripled since the 1960s. By 2016 some 650 million adults (≈13% of the world's population) were obese. In the US today roughly 42% of adults are obese, up from ~13% in the early 1960s.
Modern Evidence
A 2023 review notes that clinical trials "could never establish a causal link" between saturated fat and heart attacks, and in fact concluded that saturated fats have "no effect on cardiovascular disease" or mortality. In other words, decades of guidelines capping fat intake are being re-evaluated.
Freud's Empire and the Overlooked Adlerian Way
At roughly the same time diet fads were taking hold, psychology was under the sway of another grand narrative. Sigmund Freud founded psychoanalysis and became one of the century's most famous thinkers. His revolutionary idea was that unconscious drives and childhood experiences – especially repressed sexual and aggressive impulses – shape all behavior.
But Freud was not alone. Alfred Adler co-founded the Vienna Psychoanalytic Society with Freud, but in 1911 he broke away to form "Individual Psychology." Adler rejected Freud's emphasis on sexual drives and inner conflict. Instead, he saw people as primarily goal-directed and motivated to achieve significance and social connection.
Lessons Learned: The Peril of Single-Cause Thinking
These two historical episodes share a common pattern. In each case, early scientists gravitated toward a simple, dramatic cause for complex problems, and it caught on in the public imagination. By focusing on one flashy factor, both fields overlooked other critical pieces of the puzzle.
The consequences were real. The low-fat craze may have left us with a generation that consumed more sugar and refined carbs, arguably making the obesity and diabetes epidemics worse. The history wasn't a conspiracy of ignorance – though industry influence played a role.