Fresh Vegetables in Porto

Vegetarian Hype in Pursuit of a Noble Purpose

Last week, health reporters treated us to a steady stream of headlines claiming that “a vegetarian diet is twice as effective for weight loss.” At best, these claims are vegetarian hype. From a more skeptical view, these are deceptive claims made to serve what their source believes is a noble purpose.

The Source of This Hype

The source of this hype is a study published six years ago. It was a randomized, controlled study of a vegetarian diet compared to a more conventional diabetic diet. Through creative publication planning, the authors extracted another publication from the same study all these years later. The first publication focused on insulin sensitivity and visceral fat loss. This year’s re-publication focused on thigh fat.

It’s an interesting study, but it’s a rehash presented to the media as a new finding. This is how we build a bias of familiarity. It’s also a short-term study – only six months – with only 37 subjects in each group.

The Facts of Plant-Based Diets

This one small, short-term study does nothing to refute a rather large body of evidence for the efficacy of a variety of healthy dietary patterns. Multiple systematic reviews lead us to conclude that one size does not fit all when it comes to dietary patterns. A healthful vegetarian diet can be a perfectly good option for weight and diabetes management. Many others provide equally good outcomes. In a 2013 JAMA commentary, Sherry Pagoto and Bradley Applehans explained this point:

The time has come to end the pursuit of the “ideal” diet for weight loss and disease prevention. The dietary debate in the scientific community and reported in the media about the optimal macronutrient-focused weight loss diet sheds little light on the treatment of obesity and may mislead the public regarding proper weight management. Numerous randomized trials comparing diets differing in macronutrient compositions (eg, low-carbohydrate, low-fat, Mediterranean) have demonstrated differences in weight loss and metabolic risk factors that are small (ie, a mean difference of <1 kg) and inconsistent.

The bottom line is that good health outcomes result from a healthy dietary pattern that you enjoy and can follow for the long term.

The source of this vegetarian hype is the Physicians Committee for Responsible Medicine. This organization has an earnest commitment to plant-based diets because of its concern about animal welfare. Sustainability concerns are another reason to favor plant-based diets. Meat production, as we’ve noted here before, has a serious impact on the health of the planet.

But advancing the cause of animal rights and environmental sustainability does not require hype. Facts and truth are more persuasive in the long term.

“Fiction is a lie that is told in the service of truth.” – Tim O’Brien

Click here for the latest publication used to support this hype and here for a systematic review of different dietary patterns for type 2 diabetes. For a review of the merits of different dietary patterns in weight management, the best source is the 2013 AHA/ACC/TOS guidelines, published here.

Fresh Vegetables in Porto, photograph © Ted Kyle / flickr

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June 20, 2017

One Response to “Vegetarian Hype in Pursuit of a Noble Purpose”

  1. June 20, 2017 at 9:31 am, Phyllis said:

    Thank you. I’m tired of the guilt because I do not feel well on a vegetarian diet.