Fast Take: A Recent Study in JAMA vs. the Dietary Guidelines

Hardly a month goes by without a new nutrition research study capturing headlines. March is #NationalNutritionMonth, so, of course, another nutrition study (Micha et al.) is in the spotlight. It’s published in the Journal of the American Medical Association (JAMA) and examines the associations between intakes of specific foods and nutrients on cardiometabolic health outcomes including heart disease, stroke, or type 2 diabetes. In addition, these findings are making waves because the paper and certain media outlets are including recommendations on specific amounts and proposing that some foods be eliminated from the diet completely. We address that clearly below, but—spoiler alert—the recommendations and guidelines presented in the JAMA study are not aligned with other expert guidelines.

Luckily for us, recommendations for how these foods can be a part of a healthy eating pattern already exist in the form of the 2015-2020 Dietary Guidelines for Americans (DGAs). Since we’re food nerds and are all about digging into the science weeds, we thought we’d take this Fast Take one step further and also compare how the JAMA study findings compare with DGA recommendations.

First things first. The study estimated the association between the intake of 10 specific foods and cardiometabolic mortality. These foods included fruits, vegetables, nuts/seeds, whole grains, unprocessed red meats, processed meats, sugar-sweetened beverages (SSBs), polyunsaturated fats, seafood omega-3 fats, and sodium. The study's authors used a risk assessment model, taking data from two National Health and Nutrition Examination Surveys (1999-2002 and 2009-2012) with over 16,000 respondents to establish and link specific foods and eating styles with cardiometabolic-associated deaths in 2012.

As with nearly every scientific study, this research also has some significant limitations. For example, the authors state that their findings did “not prove that changes in these dietary habits reduce disease risk.” Additionally, in an accompanying editorial to this research, Noel T. Mueller, PhD, and Lawrence J. Appel, MD, urge that “several aspects of the study methods and findings require careful evaluation.”

But media conversation surrounding the study hasn’t been quite so careful. Some of the coverage has gone so far as to state that some of the foods included in the study do not have a place (like, at all) in our diets. Last time we checked, we rely on large bodies of research (not single studies) and guidelines such as the DGAs to support these types of statements.  

Because of this, we thought it would be interesting to directly compare recommendations stemming from the JAMA study (which are based on mortality risk) to recommendations from the DGAs (which provide guidance for choosing a healthy diet and focus on preventing the diet-related chronic diseases).

It should be pretty easy for you to see where the differences are and how you should regard the recommendations from a single study versus the recommendations from a large body of evidence.

Recommendation Source

JAMA study

DGA Healthy U.S.-Style

DGA Healthy Mediterranean-Style

DGA Healthy Vegetarian

Calorie reference

No daily calorie reference given

2,000 calories/day

2,000 calories/day

2,000 calories/day

Sodium

<2,000 mg/day

<2,300 mg/day

<2,300 mg/day

<2,300 mg/day

Nuts/Seeds

>5 oz/week

5 oz/week of nuts, seeds and soy products.

5 oz/week of nuts, seeds and soy products.

14 oz/week of nuts, seeds and soy products.

Processed Meat

0 grams/day

Processed meat can be included as long as sodium, saturated fats, added sugars, and total calories are within limits in the resulting eating pattern.

Processed meat can be included as long as sodium, saturated fats, added sugars, and total calories are within limits in the resulting eating pattern.

No meat included

Omega-3 from Seafood

>250 mg/day

8 oz/week of a variety of seafood for an average of 250 mg/day of EPA and DHA omega-3 fatty acids

15 oz/week of a variety of seafood for an average of 250 mg/day of EPA and DHA omega-3 fatty acids

No seafood included

Veggies

>8 cups/week

17.5 cups/week

17.5 cups/week

17.5 cups/week

Fruits

>6 cups/week

14 cups/week

17.5 cups/week

14 cups/week

Sugar-Sweetened Beverages (SSB)

0 grams/day

SSB can be included within overall calorie limits if <10% of total calories come from added sugars.

SSB can be included within overall calorie limits if <10% of total calories come from added sugars.

SSB can be included within overall calorie limits if <10% of total calories come from added sugars.

Whole Grains

>125 grams/day

≥48 grams/day

≥48 grams/day

≥56 grams/day

PUFA replacement of Carbs/Sat Fat

>11% of calories

20-35% of calories from total fat, with emphasis on unsaturated varieties (e.g., PUFA/MUFA). <10% of total calories from saturated fat.

20-35% of calories from total fat, with emphasis on unsaturated varieties (e.g., PUFA/MUFA). <10% of total calories from saturated fat.

20-35% of calories from total fat, with emphasis on unsaturated varieties (e.g., PUFA/MUFA). <10% of total calories from saturated fat.

Unprocessed Red Meat

<1/2 oz/day or 3.5 oz/week

26 oz-equivalents/week of meats, poultry, and eggs. No specific guidance on unprocessed red meat.

26 oz-equivalents/week of meats, poultry, and eggs. No specific guidance on unprocessed red meat.

3 oz-equivalents/week of eggs. No meats or poultry included.

So in case this study has got your feathers all ruffled about what foods you should eat and what foods you should avoid, focus instead on establishing a healthy dietary pattern that works for you and your preferences. This includes a dietary pattern that is higher in vegetables, fruits, whole grains, low- or non-fat dairy, seafood, legumes, and nuts; moderate in alcohol (if you’re an adult who chooses to drink); lower in red and processed meat; and low in sugar-sweetened foods/drinks and refined grains.

Resources:

New Dietary Guidelines: What Changed & What Stayed the Same
How Much Salt?  New Guidelines for Healthy Living
More than 'Meats' the Eye: Beefing Up on the Facts on Red Meat
Making Sense of Sugars

 
 

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