Potatoes in a Yellow Dish

Have U.S Dietary Guidelines Done Anything to Help with Obesity?

Up front, we want to say that the Dietary Guidelines for Americans are incredibly important and we are very grateful for the diverse and talented experts who are working on scientific input for the 2025 edition. They offer a framework for healthy nutrition that guides U.S. (sometimes even global) food policy in ways that are both subtle and important. But do these dietary guidelines provide a template for overcoming obesity? Could they ever? We have our doubts.

A new study in The Journal of Nutrition adds to our reasons to believe this. Evan Cohen, Dennis Bier, and Matthew Martinez found that from 1980 to 2011, following dietary guidance to limit cholesterol, saturated, and total fat “had little, if any, effect in mitigating population-wide BMI increases.”

Observational Research

Of course, this is observational research. It can neither prove nor disprove that dietary guidance to limit fat and cholesterol had a positive or negative effect on obesity prevalence. But for a while now, we’ve heard some experts adamantly claiming that low-fat diets were a disastrous mistake.

“Despite eating less fat, we are fatter than ever before,” says David Ludwig.

Cohen, Bier, and Martinez are making no such claims. They merely examined the data they had from the Nurses Health Study and concluded that it “calls into question whether there is a meaningful relationship between individual fat proportion levels and BMI and obesity outcomes.”

Obesity Comes from More Than Diet

Our conclusion from all of this is simple. Nutrition is important. Sound dietary guidance is, too. But we should stop making excessive promises about what it can do. It has not and likely will not, by itself, solve our problems with obesity.

Click here for the study by Cohen, Bier, and Martinez. For perspective on the inadequacy of food policy as a substitute for obesity policy, click here .

Potatoes in a Yellow Dish, painting by Vincent van Gogh / WikiArt

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November 28, 2023

One Response to “Have U.S Dietary Guidelines Done Anything to Help with Obesity?”

  1. November 28, 2023 at 10:01 am, David Brown said:

    In this age of hyper-specialized scientific investigative activity, motivated reasoning seems to be a major roadblock for obesity researchers. The so-called top experts who control the diet/disease narrative are not paying attention to arachidonic acid research and commentary. For example, when I confronted one of them with evidence that current average intakes of linoleic acid and arachidonic acid pose a toxicity problem, he said, “Dear Dave, The evidence in humans does not support this hypothesis, which is largely based on animal models. In large observational studies, biomarker studies, and controlled trials, LA is consistently beneficial in humans. Unfortunately I do not have the bandwidth to engage further in one on one dialogue on this topic. I hope the articles I shared are useful.”

    They weren’t.