What is Evidence-Based Nutrition?

By MIKAYLA JORGENSEN, MS, RD October 12, 2022

There is a lot of buzz online and in the media about nutrition and food. With all of the information available, it can be hard to know what to believe.

Pseudoscience and anecdotal evidence often get mixed into nutrition statements and health claims, but the best way to separate fact from fiction is to look for evidence-based nutrition.

Evidence-based nutrition is the practice of making dietary recommendations based on scientific evidence along with clinical experience. This means that the recommendations are based on current and reputable research published in scientific journals(1, 2).

The evidence-based approach is not new. It has been used for years in the medical field to develop treatment protocols.

What does evidence-based nutrition mean?

Evidence-based nutrition is the practice of making dietary recommendations based on the best available scientific evidence.

This approach to nutrition emphasizes the importance of rigorous scientific research in determining what constitutes a healthy diet and nutritional needs and seeks to dispel myths and misinformation about nutrition that are not supported by current scientific evidence.

This approach to nutrition is based on the principle that the best way to determine what is good for our health on a broad scale is to look at the evidence.

Systematic reviews of recent research are a core piece of evidence-based practice in nutrition. This is an organized way to collect research on a given topic or question and determine what all recent and relevant research has to say about it.

This means that rather than relying on our own personal opinions or beliefs about nutrition, we should look to the collective of the most current and reputable scientific evidence to see what the best nutritional recommendations should be.

What is evidence-based practice?

Evidence-based practice is a foundational pillar of the American Academy of Nutrition and Dietetics, which is the accreditation body for Registered Dietitians in the United States.

The phrase “evidenced-based” appears twice within the code of Ethics for the Nutrition and Dietetics Profession and comprises an entire domain for the dietetic internship that all dietitians must complete.

Evidence-based practice guidelines require professionals to translate systematic reviews to establish interventions and management for clinical conditions. These guidelines require continuous updating as new research is always developing.

Anecdotal Evidence vs. Scientific Evidence

One of the key distinctions between evidence-based nutrition and other approaches to nutrition is the importance that is placed on scientific evidence. Anecdotal evidence, such as personal experiences or stories, is not given the same weight as scientific evidence in this approach.

This is because anecdotal evidence is often not reliable. Personal experiences can be influenced by a number of factors, including personal biases, and so they are not always accurate reflections of reality.

In contrast, scientific evidence is based on rigorous and validated research and so is much more reliable.

This is not to say that anecdotal evidence is completely worthless. It can still be useful, for example, in identifying possible areas for further research. However, it should not be the only evidence used to share nutrition information or establish nutrition guidelines.

Anecdotal Evidence

Have you read clever marketing strategies like these online? "I tried this diet, and it worked great for me!" or "I know someone who tried this diet, and they lost a lot of weight!", even “what I eat in a day” videos that allude to the idea if you eat like them you will look like them.

This type of information is being even more widely distributed with the rise of influencer marketing, specifically on platforms like TikTok and Instagram, and can make finding reliable information even more challenging to find.

These claims are made all the time, but they are not based on scientific evidence. Instead, they are based on personal experiences or stories, which are not always accurate or representative of the general population.

Scientific Evidence

Nutrition information is based on scientific evidence or "evidence-based" when they have rigorous research that is reputable and published in scientific journals to support the information or claims.

This evidence is much more reliable than personal experiences or stories, and so it should be given more weight when making dietary recommendations and prescribing nutrition interventions.

When looking at the scientific evidence, it is important to consider the quality of the studies that have been conducted, as well as the quantity (3).

For example, a single small study is not going to be as reliable as multiple, large, well-designed studies. In general, the best evidence comes from large, well-designed studies that have been conducted in a variety of different populations and over longer periods of time.

While nutritional science is a growing field, like any medical field, it remains a challenging field to study. Compounding variables, including participant adherence and other lifestyle factors and family history, are difficult to isolate, monitor, and control (4).

It's difficult to identify a cause-and-effect relationship between nutrition factors and conditions when so many different factors are at play, like obesity, diabetes, and heart disease. This is why you'll often see "associated" with whatever outcome and not "causes."

When looking at the evidence, it is also important to consider the potential risks and benefits, which is the recommendation for nutrition and medical professionals to utilize critical thinking and clinical judgment.

For example, a diet that has been shown to be effective for weight loss is not necessarily going to be the best option for someone who is trying to improve their overall health.

Where to find evidence-based nutrition information (and where not to)

There are many places to find evidence-based nutrition information. A few reputable sources include Registered Dietitians, the Academy of Nutrition and Dietetics, the American Heart Association, the Centers for Disease Control and Prevention, and the NIH (the National Institute of Health).

You can also find evidence-based nutrition information on the websites of many professional organizations, such as the American Heart Association, the American Academy of Pediatrics, and the American Dietetic Association. However, you should be careful about trusting nutrition information from sources that are not reputable. For example, you should be wary of information from websites that sell supplements or weight-loss products, as this information may be biased.

To be able to determine if a source is credible, it is recommended that you seek feedback from one or more of the following sources:

Registered Dietitians

A registered dietitian is someone who has completed an accredited bachelor's degree program in dietetics, completed an accredited internship with a minimum of 1200 hours of supervised practice, and passed a national registration examination.

Dietitians or RD's work in a variety of settings, including clinical, private practice, community/public health, and for companies that utilize credentialed nutrition experts.

One of the major roles of dietitians is to stay updated on current research and help translate it into individual recommendations for clients and patients, as well as help to make nutrition information more understandable for the public.

Credible Websites

When looking for credible websites, a great place to start is with websites that end in ".gov" or ".edu." These websites are more likely to provide accurate and reliable information as they are associated with accredited organizations.

It is still important to look at the research, though, as lobbying has become a common political activity, which can influence the accuracy of the information provided by these websites.

For instance, dairy farmers in the United States have been known to lobby for changes in school lunch programs that would require students to drink milk. This is shown on websites like MyFoodPlate (run by the US Department of agriculture) which insists all meals should have a glass of dairy milk.

This is not to say there is no research behind this recommendation, but it is worth looking considering lobbying and funding when doing your own research.

The Academy of Nutrition and Dietetics (AND) is the world's largest organization of food and nutrition professionals. The AND's website provides a variety of evidence-based resources on nutrition and health, including a Nutrition Evidence Library, which contains summaries of the latest research on a variety of topics.

Also, check out:

Do Your Own Research

The best way to become an informed consumer of nutrition information is to do your own research.

When you come across a claim about nutrition, try to find scientific evidence to support or refute it or consult an expert in the field to help you with this.

A good place to start your research is the National Library of Medicine's PubMed database or the NIH database. These databases contain abstracts of scientific articles on a variety of topics, including nutrition.

It’s important to note that just because one study supports an idea does not mean that it is universally true or should be applied to the general population. For this to be done, there should be several studies from different sources that come to the same conclusion.

When searching for answers, avoid personal claims and anecdotes, as these are not scientific evidence. Instead, look for scientific studies that have been published in peer-reviewed journals. These studies have been vetted by other scientists in the field and are more likely to be accurate.

Key Takeaways

Anecdotal evidence may lead you to believe that something is fact when it actually it isn't. Because of that, it's important to be critical of your sources and look for scientific evidence to support claims about nutrition and health.

When looking for credible sources of nutrition information, look for websites that end in seeking out nutrition experts like registered dietitians and companies that utilize these experts and refer to credible and evidence-based websites.