Dietary Fat: Beyond the Headlines
Based on the work of Gary Taubes, a science journalist and author
Gary Taubes is a science journalist and author who has spent decades investigating nutrition science, obesity, diabetes, low-carbohydrate diets, and the history of dietary advice.
He argues that the media helped turn the idea that dietary fat causes heart disease into accepted wisdom before the scientific evidence justified that degree of certainty.
Taubes is particularly critical of the way complicated nutrition research gets reduced to simple messages such as “fat is bad.” His work has made me more skeptical of nutrition headlines—and more interested in asking a basic question: How strong is the evidence behind the advice?
How Fat Became the Villain
Taubes traces much of the modern fear of dietary fat to research beginning in the mid-20th century, including the influential work of Ancel Keys and the Seven Countries Study.
Keys' research supported an association between diet, cholesterol, and heart disease and helped shape subsequent thinking about saturated fat. Taubes argues, however, that the evidence was less conclusive than the public was led to believe.
In his view, scientists, public-health authorities, and journalists gradually transformed a hypothesis into something often presented as established fact.
The Media's Role
One of Taubes' main criticisms is that nutrition science is frequently oversimplified.
The relationship between diet and health is extraordinarily complicated, yet media coverage often reduces it to easily understood messages: fat is bad, cholesterol is bad, or a particular food is either healthy or unhealthy.
Taubes argues that contradictory evidence has often received too little attention and that journalists do not always examine the weaknesses of nutrition studies carefully enough.
The Problem With Nutrition Research
Nutrition science is difficult.
Researchers can't easily control what thousands of people eat for decades. Instead, many studies rely on people reporting their own diets while researchers observe what happens to their health.
Such observational studies can identify associations, but they cannot by themselves establish cause and effect.
Someone who eats more vegetables, for example, may also exercise more, smoke less, receive better medical care, or differ in many other ways from someone who eats fewer vegetables.
Taubes believes journalists too often report these associations as though they demonstrate causation.
What Replaced Fat?
Beginning in the late 20th century, Americans were repeatedly encouraged to reduce dietary fat. Food manufacturers responded with thousands of products marketed as low-fat or fat-free.
Removing fat, however, often meant replacing it with sugar or refined starches to maintain taste and texture.
Taubes argues that the resulting increase in refined carbohydrates may have contributed to obesity, insulin resistance, and Type 2 diabetes.
The timing alone doesn't prove causation. Many aspects of American diets and lifestyles changed during the same period. But Taubes believes the experience should make us question whether the low-fat approach produced the health benefits that were expected.
Evidence That Didn't Fit
Studies examining saturated fat and cardiovascular disease have not always produced consistent results.
Some systematic reviews and meta-analyses have questioned how strongly saturated fat intake, considered by itself, predicts cardiovascular disease. Other researchers emphasize that the health effect depends importantly on what replaces saturated fat in the diet.
Taubes' larger criticism is that this scientific uncertainty has not always been communicated clearly to the public.
Sugar and Refined Carbohydrates
As Taubes investigated obesity and nutrition, his attention increasingly shifted toward sugar and refined carbohydrates.
His book The Case Against Sugar examines the history of sugar consumption and the evidence connecting excessive sugar intake with obesity and metabolic disease.
There is broad agreement that excessive added sugar, particularly from sugar-sweetened beverages, is undesirable.
Taubes goes further. He argues that sugar and refined carbohydrates have played a larger role in obesity and metabolic disease than conventional nutrition advice has acknowledged.
Industry Influence
Taubes has also examined the influence of the food industry on nutrition research and public opinion.
Historical investigations have documented instances in which the sugar industry funded research and public-relations efforts that emphasized dietary fat and cholesterol while minimizing concerns about sugar.
For Taubes, this illustrates another reason journalists should examine who funded research and whether financial interests may have influenced the questions being asked or the way results were presented.
Is Nutrition Science Ever Settled?
Taubes is skeptical when complicated questions in nutrition are described as completely settled.
Scientific consensus matters, but science also advances when researchers test and challenge existing explanations.
Once an idea becomes incorporated into medical advice and government policy, Taubes argues, it can become difficult to reconsider. Researchers build careers around prevailing ideas, organizations issue guidelines based on them, and journalists repeat them.
He believes good science requires continuing to ask whether the evidence supports those assumptions.
What Should Health Journalism Do Better?
Taubes argues that health journalists should critically evaluate the quality of research rather than simply report its conclusions. They should distinguish association from causation, avoid sensational headlines, explain uncertainties and conflicting evidence, and investigate potential conflicts of interest.
Conclusion
I find Taubes convincing—not necessarily because every conclusion he reaches will ultimately prove correct, but because of the question he keeps asking:
What does the evidence actually demonstrate?
That is especially important in nutrition, where confident recommendations have sometimes changed as the evidence has evolved.
After reading Taubes, I became much less interested in asking, “What does everybody say I should eat?”
I became more interested in asking:
“What is the evidence?”
Learn More
Books by Gary Taubes
Good Calories, Bad Calories; The Case Against Sugar; The Case for Keto; Rethinking Diabetes, and other books.
Uncertainty Principles
Gary Taubes's newsletter on nutrition science, health research, and how scientific evidence is interpreted.
In Defense of Bad Health Journalism
Taubes discusses health journalism and the difficulties of accurately reporting nutrition science.
As Obesity Rates Skyrocket, Dietary Guidelines Go From Being Pro-Vegetable to Anti-Meat. How'd That Happen?
Taubes examines the history and evolution of American dietary recommendations.
The “One of Us Stinks” Problem: LDL, the Lipid Hypothesis, the AHA, and Humphrey Bogart
An examination of LDL cholesterol, heart disease, and the history of the lipid hypothesis.