Public Guide to Nutrition Studies in Media, News and the Internet
Whether you're reading an article from a famous newspaper, listening to a celebrity or influencer on social media, watching a YouTube video, or simply talking to your friends or co-workers, food and nutrition can be very confusing and downright scary! In this article, we will explain the different types of studies you will see in nutrition and how you can simply find relevant information. Just like how you take your driving test before driving your car, you can think of this guide as a way to navigate the waters online! This article is written after talking to experts and researchers in this field. This is what you need to do:
- Ask for or look at the study.
- Evaluate against the evidence diagram below
Whether you're reading an article from a famous newspaper, listening to a celebrity or influencer on social media, watching a YouTube video, or simply talking to your friends or co-workers, food and nutrition can be very confusing and downright scary! In this article, we will explain the different types of studies you will see in nutrition and how you can simply find relevant information. Just like how you take your driving test before driving your car, you can think of this guide as a way to navigate the waters online! This article is written after talking to experts and researchers in this field. This is what you need to do:
- Ask for or look at the study.
- Evaluate against the evidence pyramid
Let us now explain what everything means, starting from the weakest forms of evidence.
- Anecdotes, opinions, influencers, celebrities, diet books, articles, co-workers, and social media groups and accounts: Normally, this starts as "I tried XXX and I got XXX." This is merely a personal observation and you should not be using this as a lifestyle or dietary change for yourself. These kinds of observations are confounded and without proper scientific rigor, these are misleading and generate lots of bad information which can have drastic consequences. The entire internet landscape is dominant in this source of thinking.
- Cell culture or vitro study: If you look at the study, you may notice, upon closer scrutiny, that it may not even be in human beings. When scientists want to isolate a certain mechanism, they use cell cultures or Petri dish studies to see what may be going on. These studies may not translate into humans or may not be substantial enough to be something worth being concerned about.
- Animal or Vivo studies: Next up from cell studies are animal studies which can be good models for certain things like the toxicology of a substance or may further study a mechanism while still not causing any harm to human lives. Usually, mice and pigs are used and these studies are usually to be taken with a grain of salt when it comes to humans.
- Case Reports: Sometimes, in a clinic or research setting, unique outliers or cases are studied to see what may be going on. In such settings, an individual is studied in a controlled environment. Though these studies have a human subject, due to the low sample size, these studies are usually used as a thought process to generate a hypothesis for further human studies.
- Cohort, Observational or Epidemiological studies: These studies compare different populations or follow a population to see what is going on. These studies will follow thousands of people using questionnaires and regular meetings with the scientists in the study. These studies are usually very confounded since associations don't equal causation and serve as a starting point to further high-quality human studies. However, a strength of these studies is that they may be good at ruling out a certain factor or mechanism. In short, they may serve as a good check for something that may be going on but they aren't good at finding cause and effect unless they do meet the Bradford Hill criteria which is an advanced set of criteria where something starts approaching a cause and effect.
- Randomized Controlled Trials: These are high-quality human studies that can be used to get a very good understanding of what may be going on in humans.
- Meta-analysis or systematic review: Scientists pool several papers together and then evaluate them all together using certain criteria. Depending on the criteria, these studies can be exceptionally strong pieces of evidence or be very poor with confounders.
- A double-blind placebo-controlled study: These studies have both the experimenter and the subjects blinded to whatever intervention is being carried out and the subjects are also given a placebo so that there is as little bias as possible in such studies. These can be the most powerful form of study.
A note on diet-based studies: Diet-based studies, though can be good starting points or excavate interesting mechanisms, are usually confounded by many variables within the foods. Additionally, consumers have a very different interpretation of the kind of diet the experimenters may be using in their study. Therefore, diet-based studies are relatively weak and confounded.