Nutrition
What should you eat? There are lots of claims about what you should and should not eat. For example, there are claims that chocolate causes acne, that it stimulates sexual desire, and that it is good for your heart. How can you know which of these claims are trustworthy? And how should you decide when to act on claims about what foods, drinks, diets and nutrition supplements are good or bad for your health?
A “nutrition intervention” is any action related to foods, drinks, diets and nutrition supplements that intend to improve health, including treatment, prevention, or management of a health problem. For example, eating vegetables and fruit daily, not eating a lot of junk food, or taking a vitamin supplement. It can also be something that we do for the health of a community — for example, making sure that water is safe to drink, making sure everyone has access to healthy foods, or making sure that mothers are informed about the benefits of breastfeeding.
An “effect” of a nutrition intervention refers to the result or consequence of that intervention—like making overweight people lose weight, making people constipated, making people more or less likely to have a heart attack or a stroke, or restoring the levels of iron in pregnant women’s blood.
A “claim” is a statement that something is true that could be right, but could also be wrong. People make lots of claims about the effects of nutrition interventions. How can we tell which claims are right or wrong? To do this, you need to look at what supports their claim – its basis. For example, someone’s personal experience is not a good basis for a claim about what is good for your health. This is because we don’t know what would have happened if that person had done something else.
To know if a nutrition intervention (like eating chocolate) causes an effect (like sexual desire), the nutrition intervention has to be compared to something else (like not eating chocolate). Researchers compare a nutrition intervention given to people in one group with something else given to people in another group. These comparisons of interventions provide evidence – information used to support a conclusion about whether a claim is right or wrong. For these comparisons to be fair, the only important difference between the groups should be the specific nutrition intervention they received.
A good choice is one that uses the best information available at the time. For nutrition choices, this includes using the best available evidence of effects of nutrition interventions. Good choices don’t guarantee good outcomes, but they make good outcomes more likely.
The key concepts for nutrition are only relevant for questions about nutrition interventions that can be best answered by fair comparisons of interventions. There are other questions that are best answered using other types of studies.
Many claims about the effects of nutrition interventions are not trustworthy. Often this is because the basis for the claim is not trustworthy. The first (pink) group of guides are things you should watch out for when you hear or read a claim about a nutrition intervention – foods, drinks, diets and nutrition supplements that intend to improve health.
It is always a good idea to question what evidence there is to support a claim. Evidence about the effects of nutrition interventions comes from comparisons of interventions. The second (yellow) group of guides can help you decide how trustworthy that evidence is.
Knowing how trustworthy the evidence is can help you make good nutrition choices. But there are other things you need to think about when you decide what to do and what not to do for your health. The third (blue) group of guides can help you make good choices.
There are endless claims about nutrition interventions in the media, advertisements, and everyday personal communication. This includes claims about the effects of specific foods and drinks; claims about diets and lifestyle changes; claims about nutrition supplements; claims about public health nutrition and environmental interventions; and claims about changes in how nutrition care is delivered, financed and governed.
Some of these claims are true and some are false. Many are not supported by trustworthy evidence: we do not know whether they are true or false. Claims about the effects of foods, drinks, diets and nutrition supplements that are not supported by trustworthy evidence often turn out to be wrong. Consequently, people who believe and act on these claims waste resources and suffer unnecessarily by doing things that do not help and might be harmful, and by not doing things that do help.
We developed the Informed Health Choices (IHC) Key Concepts as the first step in a research project with the aim of helping people make informed health choices. This website includes all of the IHC Key Concepts (guides). The IHC Key Concepts are the starting point for developing learning resources, such as this website.
The website and the poster can be used in different ways. For example, finding nutrition claims in the media and – using the guides – thinking critically and discussing how trustworthy these claims are and what you would do.
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We are an international group with decades of shared experience in health research, medicine, public health, design, education, communication and journalism. You can find out more about us here.
This website has been developed by the Centre for Informed Health Choices at the Norwegian Institute of Public Health, InfoDesignLab, and the Epistemonikos Foundation.
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