Frequently I see the claim that dietary guidelines are the reason we are overweight and sick. It is used to sell books, particular diet strategies, or just to inject doubt about government agencies and nutrition science. This of course rests on the assumption that people are following the recommendations. Some groups have explored the proportion of the population that meets recommendations for various food groups. A good paper is by Krebs-Smith and colleagues from 2010, who used NHANES ’01-’04 data and produced a nice table here. A point of emphasis: overall, about 80% and 89% were below fruit and vegetable recommendations, respectively. Already we know that people aren’t following the guidelines.
I used NHANES ’09-’10 data to do a similar analysis, because I wanted to see if anyone met the guidelines for all food groups, and also to see if we are anywhere close. Since this is the most recent data available, we need to use the MyPyramid recommendations, which was replaced by MyPlate in 2011. The following recommendations (which were designed to meet nutrient needs within calorie limits) were used based on calorie level, except for discretionary calories which I omitted for simplicity.
Calorie levels were estimated for each person based on age and activity. A section of NHANES asks participants about activity, so I designated active as being physically active for at least 60 minutes a day for at least 5 days per week.
The proportion of Americans achieving recommendations for fruits, vegetables, grains, meat & beans, milk, and oils: 0.098%. Yes, you read that right: it is 1/10th of 1%.
If we add in another recommendation – to make half of all grains whole - 0% of the population meets recommendations. There are additional recommendations for vegetable subgroups that aren’t even worth exploring because nobody is left.
Looking at only the proportion who meet recommendations for both fruits and vegetables, it is 5.5%. The milk group alone is 18.3%. Only 5.9% made half of their grains whole.
Are We Even Close?
To see if we are even on the right track to meet recommendations, I cut them all in half. So at 50% of the recommendations for fruits, vegetables, grains, meat & beans, milk, and oils, 3.3% of the population now reaches them. If we cut the whole grain recommendation to 25% of total grains and include this, we are back below 1%: 0.81%.
The state of the American diet is grim. I previously estimated the proportion of the U.S. population achieving recommendations for 21 micronutrients: 0.5%. The proportion of the population meeting food group recommendations is even lower, and in fact on average, it is 0%. Even being generous and cutting recommendations in half, we are still at less than 1% who meet them.
When someone says our guidelines make us sick, they simply don’t understand the science. Many studies use the Healthy Eating Index, which directly measures how closely each individual adheres to recommendations. For example, Reedy and colleagues published a paper earlier this year associating a higher Healthy Eating Index score with a reduced risk of all-cause, cardiovascular disease, and cancer mortality in the NIH-AARP Diet and Health cohort of 424,662 people. We can also infer from similar healthy consumption patterns (e.g. high fruits and vegetables, whole grains etc) that shifting toward the guidelines would improve population health. An exhaustive review is outside of the scope of this post, but for some additional references, see this nice slide set by Reijo Laatikainen.
Notes & Caveats
This analysis uses one weighted 24-hour recall from NHANES. It is known that self report food intake is not great for some things and some foods may be underestimated while others are overestimated. It would be ideal to use the NCI method to improve estimations of usual food intakes, but for simplicity I have not yet done this. I also did not explore outliers. There is no direct match for “active” as defined for the MyPyramid calorie levels in NHANES, so I used my best judgement of which to use.