Over the Christmas and the New Year period I was thinking a lot about the abundance of nonsense nutritional information out there. I was feeling frustrated by how misleading this information can be, which leaves a lot of people feeling confused about what nutritional advice to believe. So inspired by Carl Sagan’s “Baloney Detection Kit” and the more recent version by Michael Shermer I decided to put together a similar tool to help people filter out misleading and false nutrition claims. Read on to find how ☺
Step One: Is the Source Reputable?
There is a big problem with the “everyone is a nutrition expert” complex.
This includes airbrushed celebrities promoting fad diets, unaccredited nutritionists providing misleading information and journalists with no training in nutritional science basing sensationalist headlines on misreported research.
In most countries “Dietitian” is a legally protected term for a qualified health professional that “assesses, diagnoses, and treats dietary and nutritional problems at an individual and wider public-health level”. Dietitians must adhere to a code of professional conduct which includes acting ethically and staying up to date with the latest research and evidence based guidelines1.
There are registers of Dietetic Bloggers who sign up to specific disclosure guidelines to blog with integrity, declare conflicts of interests and strive to provide accurate information. Click on the following links to access the disclosure guidelines for the UK and USA , you can see my own disclosure policy here.
“Nutritionist” isn’t a protected term so unfortunately anybody can call themselves a Nutritionist whether they have been to university or not; which is confusing for the public and frustrating for qualified Nutritionists. However there are voluntary registers for Nutritionists in most countries to highlight accredited nutritionists who meet specific “training, competence and professional practice criteria”2-4. See this post by Gemma from Dietitian Without Borders for further information about the registration standards of dietitians/nutritionists around the world.
There are also “Nutritional Therapists” who may have a university degree, but in the UK these degrees are accredited by complementary and alternative healthcare groups5, therefore the advice and treatments offered are often based on complementary “medicine” and an evidence base that isn’t recognised by mainstream established science2.
As with any claim it is important to think about whether the author could have a specific agenda, conflict of interest or whether their personal beliefs rather than good quality evidence could be driving their claims.
Step 2: Look Out for Nutritional Nonsense Red flags
There are specific types of nutritional nonsense, usually related to fad diets, which should scream out CAUTION when we read them!
Here are some of the main red flags to look out for:
Obsessive focus on specific foods or nutrients
e.g. Cabbage diet, juice diets, raw diet
e.g. 7 day fasting diets, cutting out food groups such as advising avoidance of dairy/gluten without a medical reason
e.g. Lose 2 stone in 1 week, drink this milkshake to burn stomach fat
Magic bullet solutions that sound too good to be true
e.g. “Secret” or “magic” minimal effort weight loss solutions without making longterm lifestyle changes
e.g. Tea detox diet, juice detoxes etc (the body’s organs have its own system to remove toxins, a detox diet won’t impact on this!)
One diet fits all advice
Not taking into consideration specific medical conditions, psychological and social factors.
e.g. The dairy industry/big pharma are out to get us so don’t listen to any main stream nutrition advice
e.g. Promote diets rather than medical treatments such as the alkaline diet rather than cancer treatment (which can have devastating consequences)
Based on complementary “medicine”
e.g. Colonic irrigation, kinesiology for faux allergy testing, hair mineral analysis
Encouraging megadoses of vitamin and mineral supplements
e.g. Cocktails of vitamins or minerals for “optimum nutrition” without a specific medical reason.
Focus on appearance rather than health
e.g. “Wrinkle fighting smoothies”
Pressure to buy something
e.g. Books, supplements, subscriptions etc
Recommending eating non-food substances
e.g Charcoal diet, cotton wool diet
Demonizing certain foods
e.g. #cleaneating suggests that all processed foods are not “clean”, whereas there are plenty of healthy processed foods such as tinned chickpeas or frozen vegetables
Step Three: “Extraordinary Claims Require Extraordinary Evidence” – Marcello Truzzi
Even a reputable source can make false claims so examining the actual evidence itself is the most important step in ruling out the nonsense!
This is a skill that can take a bit of practice to develop but it is such a powerful tool in understanding what is actually being claimed. For UK based headline’s NHS Choices has an excellent resource called “Behind the Headlines” which challenges the evidence of the headlines and summarises this in a very accessible way.
If you want to examine the research yourself, here are some of the main points to check:
Does the media headline actually match the findings of the evidence it is reporting about?
For this you can look up the author’s results and conclusion. It is especially important to check whether the results were statistically significant or not (this can be a complicated area if it is new to you, check out this blog post by the Minitab Blog for further information).
Is the story reporting the results of just one study?
It would be rare for a single study to contain enough evidence to change nutritional advice, so it is important to look at the wider context of research to see where the study fits in.
What type of study was it?
Different types of studies have different advantages, disadvantages and strengths of evidence (see image below for main types of studies).
Click here for a diagram of the scientific method
In general randomised control trials (RCTs) are the best direct studies to show whether a result is due to a specific intervention, because of the use of a blinded control group (i.e. the participants don’t know if they are in the intervention or control group). The evidence is stronger if the researchers also don’t know which participants are in which group (i.e. a “double blind” RCT) as this further reduces possible bias. For robust evidence the results also need to be able to be replicated by others, and there needs to be the possibility that the claim can be proven false (i.e. falsifiable).
The strongest evidence to prove an overall claim comes from studies called systematic reviews which summarise the main body of evidence in relation to a specific question (for example: are there any health benefits to drinking alcohol?) in a methodical way, this is then analysed using a statistical method called a meta-analysis.
How big was the study?
Larger studies produce more statistically reliable results.
Was the study carried out in petri-dishes, in animals or in humans?
Although research conducted in petri-dishes and animals can produce useful preliminary results, we are unable to directly translate this evidence to apply to humans. So generally specific nutrition claims need to be tested in humans (where this is ethically possible).
What are the limitations?
Often for ethical or practical reasons studies related to dietary intake can have limitations, for example self-reported intake of what a person has eaten in a day; which can often be inaccurate.
Also, as nobody lives in vacuum there can be many confounding factors involved; for example if a study showed that women who consume soya products have specific improved health outcomes, this could also be related to other factors such as also exercising more, living in a different part of the world, also eating more fish etc.
Sometimes markers for diseases (e.g. blood pressure or cholesterol levels) rather than actual diseases (e.g. heart disease) will be used as the end points in research. However as these markers don’t always develop into the disease in question this type of evidence doesn’t tell the whole story.
I really hope that this toolkit will be useful in helping you to avoid some of the nutritional nonsense that we are bombarded by, because this is not only confusing but can cause real harm in some cases (For more on this potential harm see this informative blog post by the nutrition guru and chef “Everyone’s a Nutrition Expert”, or my post on “10 Reasons to Avoid Fad Diets”).
Distinguishing between credible advice and nutritional crap isn’t always easy to do, as Michael Shermer says with science there are varying scales from “probably true to probably not true”. Using critical thinking from a skeptical point of view and checking out the actual evidence behind the claims is the best way of getting to the bottom of it.
“Science is the best tool ever devised for understanding how the world works” (Michael Shermer); so if we apply this to the world of nutrition we can avoid all of those false nutritional claims and lead healthier, happier, nutritional nonsense-free lives!
Maeve 😀 xx
- Michael Shermer Balony detection kit https://www.youtube.com/watch?v=aNSHZG9blQQ