Why Does Nutrition Advice Contradict Itself?

Home » Nutrition » Why Does Nutrition Advice Contradict Itself?

One day coconut oil is a cure-all, the next it will kill you. Coffee is good! No, it’s bad. Carbs are evil and then they are a necessity. Why is there so much contradiction when it comes to nutrition advice? It results in confusion and mistrust. Therefore, I thought it appropriate to write a post on why these contradictions occur and what you can do to make sure you are getting the most accurate information possible.

The Media

Most people obtain their nutrition information from a media source. When it comes to getting views and clicks, the more sensational the headline, the better. The media is prone to use hyperbole when reporting on scientific studies. For example, when a study found that butter had a neutral effect on cardiovascular disease risk when compared to other foods, the TIME magazine headline read, “Butter is Back!” Hey, there are magazines to sell! (Read more about this in my post on Saturated Fat.)

When the media overstates results of studies, this lends to the confusion that consumers experience. One day butter will kill you, and the next day it will save you. When you read the actual studies behind the headlines, the authors are much more reserved in their analysis.

The Nature of Evidence-Based Advice

Often the media will take one small study and run the result as if it is absolute fact. However, the way that good evidence-based advice is formed takes time and a multitude of studies. In this way, a good case can be built for giving a nutrition recommendation.

The types of studies also matter. There is a hierarchy of scientific evidence that classifies which study designs are strongest. For example, a randomized clinical trial holds much more weight than a case study. Unfortunately, study design is not always taken into account.

Finally, recognize that nutritional science is constantly evolving. Evidence builds upon itself, and nutrition advice sometimes needs to be clarified, modified, or completely changed based on the progression of evidence.

When taking nutrition advice, whether it be from a professional or a media outlet, be sure that it is built on sound scientific evidence. Confirm that supporting references point to peer-reviewed literature. Ask critical questions about supporting studies, including their type and reproducibility.


Bias exists in most all situations. To arrive at good nutrition advice, we do our best to eliminate as much bias as possible. For example, good scientific studies try their best to eliminate bias on the part of the researchers. Researcher are human after all, and can be biased towards a particular result, or perhaps influenced by a funding source.

In addition, most all of us have some level of “confirmation bias.” This means that we tend to favor evidence that upholds our preexisting beliefs and ignore evidence that contradicts them. When we become aware of this quality of human nature, we can approach life with a more open mind. Be aware that your own bias affects your ability to accept and process nutrition advice as well. (This goes for RDs, especially! We can also get entrenched in some rigid views of food, weight, and health).


In the age of “fake news” it can be difficult to discern which sources to trust. Most anyone can label themselves a nutrition expert and share advice. It’s pretty easy for anyone to start a blog, Facebook page, or Twitter account and start handing out advice.

Be wary if the source of the information is also trying to sell you something (even if they are a professional). For example, Dr. Oz dishes advice that is credible on one segment and out of left field on the next. Even though he is an MD, he is in entertainment and the producers of his show are looking for television that will sell. (Sorry to bash your beloved Dr. Oz, Mom!)

Seek out nutrition information from sources that strive to be unbiased and based on scientific evidence. One example is The Academy of Nutrition and Dietetics. Academic institutions are also usually reliable sources.


It’s up to us to be responsible consumers of nutrition advice. Here’s a summary of tips to do so:

  • Obtain nutrition information from reliable, evidence-based sources.
  • Be wary of any source that is trying to sell you something, despite their credentials.
  • Look past the headlines and scrutinize the strength of the research being reported on.
  • Consider bias that might exist from everyone involved: the researchers, authors, and even yourself.

Leave a Reply

Your email address will not be published. Required fields are marked *

Best Nutritionists in Phoenix

For your health and well being.