KEY POINTS

  • Changes to defining "moderate drinking" could have real negative consequences, including undermining Americans' trust in nutrition and health guidance.
  • Americans deserve science-based nutrition guidance on all aspects of diet, including alcohol.
  • Men may just ignore these new guidelines if they don’t think they can trust the science behind them or women will now think they can drink as much alcohol as men.

If a man has two beers at a family cookout, is he no longer a moderate drinker?

Incredibly, some researchers say yes -- and they're poised to incorporate their irrational definition into official federal guidance. That'd be a huge departure from current federal guidelines, which since 1990 have defined "moderate drinking" as two drinks for men and one for women.

This change could have real negative consequences, including undermining Americans' trust in nutrition and health guidance.

Every five years, an independent committee of experts reviews the current body of research and submits an advisory report to help the federal government determine the latest "Dietary Guidelines for Americans." These guidelines serve as the standard for healthcare professionals and influence everything from doctors' advice to school lunches.

This July, the advisory committee made its official recommendations for the 2020-2025 guidelines, including the misguided proposal to change the decades-long definition of moderate drinking. The U.S. Department of Agriculture and Department of Health and Human Services will determine whether to officially implement the DGAC's recommendations by year's end. 

Given the wide-ranging authority of these guidelines, the committee is required to assess a body of evidence. Yet to justify its alcohol recommendation, this committee cited only one study that even compared one versus two drinks. This directly contradicts the committee's charter, which states that its recommendations must be based on a preponderance of evidence.

On top of that, the single study has been decried by health experts for its flawed methodology. It compared two groups of drinkers -- one versus two drinks -- but made no comparison to a control group of non-drinkers. This goes against widely accepted scientific protocol. 

Furthermore, although the committee had access to relevant studies spanning from 2000 to 2020, it only reviewed studies from 2010 through 2020. According to Dr. Eric Rimm, a 2010 committee member of the DGAC and professor at Harvard's T.H. Chan School of Public Health, 80 percent of the rigorous alcohol studies were conducted between 2000 and 2010  -- a period the committee chose to ignore. Dr. Rimm notes that well-designed studies of alcohol and health can require 20 to 40 years of follow-up and that recent studies may not necessarily be the strongest.

Further, it makes zero sense to apply the same single-drink "moderate drinking" guidelines to both men and women. Ignoring the differences in how men and women handle alcohol is irresponsible, since they metabolize alcohol in very different ways. A woman who consumes the same amount of alcohol as a man is likely to reach a higher concentration of alcohol in her blood due to differences in physiology. According to Harvard Women's Health Watch, "one drink for a woman is roughly equivalent to two drinks for a man."

And as the DGAC discussed in its scientific report, there are both potential risks and benefits to consuming alcohol. In fact, the DGAC reviewed numerous studies that found that moderate drinking was associated with reduced risk of all-cause mortality compared with never drinkers.

As I advise consumers, if someone doesn’t drink alcohol, there is no reason to start. But if they do drink alcohol, they should have unbiased, evidence-based information so they along with their doctor or health professional can evaluate what is best for them.

Adopting unrealistic guidelines that suggest that men who have a second glass of wine at dinner are problem drinkers could backfire. As a registered dietitian nutritionist, I fear men will just ignore these guidelines if they don’t think they can trust the science behind them or that women will now think they can drink as much alcohol as men.

While the committee’s recommendations may be well-intentioned, Americans deserve science-based nutrition guidance on all aspects of diet, including alcohol.

Kathleen Zelman, MPH, RDN, LD, is a registered dietitian nutritionist. She is the owner of No Nonsense Nutrition, LLC. and serves as a nutrition advisor to the Distilled Spirits Council.