We get questions asking "Is [this foodstuff] healthy/unhealthy?"


Such questions may be overly broad, vague and problematic. What additional criteria should such questions meet?

Note: I am ignoring the prescriptivist healthy vs. healthful debate.


2 Answers 2


I think we should allow questions that present a notable claim and ask "is that true?"

The problem with many of your examples is that they don't provide an example of a notable claim to be examined. Those that do provide a notable claim are actually good questions if you get past the vague title, which is really just supposed to be shorthand anyway. This site is for examining notable claims.

Alternative solutions to the problem examples you listed. Seems to me all could be solved by just requiring a quote of a notable claim.

  • Is the 'Subway diet' healthy?
    • There is no notable claim that the subway diet is healthy. The actual claim is that Jared Fogle lost weight on such a diet.
  • Is Soy bad for you?
    • There is no example of the claim quoted. Perhaps Tim Ferriss had a much more narrow and specific claim about the healthiness of soy in his book.
  • Do oxygen bars provide health benefits to a normal person?
    • There is no example of the claim quoted. Wikipedia has several very specific claims that are could have been challenged rather than the vague question that was actually asked.
  • Do people need to drink 8 glasses of water a day?
    • There is no example of the claim quoted. In most sources of the 8-cups-a-day claim that I could find right now, they qualify it as being about fluid, or just a guideline, etc. Had the asker provided an example of the claim, it would have come along with useful clarification.
  • Is water or tea dangerous for young infants?
    • This question's title might be vague, but the actual claim being challenged is clear: "In rare cases, a baby who drinks too much water can develop a condition known as water intoxication, which can cause seizures and even a coma." The answer addresses that claim directly. It is a good question.
  • Are raw button mushrooms unhealthy (especially carcinogenic)?
    • The title might be vague, but the actual claim being challenged is clear: "The list of edible mushrooms considered safe for raw consumption is quite short. Even species commonly eaten raw, especially the ubiquitous button mushroom, Agaricus bisporus, have their drawbacks. Buttons, and many other edible mushrooms contain various hydrazines, a group of chemical compounds generally considered carcinogenic." The answer addresses this directly. It is a good question.
  • Should a healthy adult take a daily multi-vitamin?
    • No notable claim is quoted. Of the examples I found when searching for one, most were narrower than "a healthy adult should take a multi-vitamin". They said things like "A daily multivitamin, and maybe an extra vitamin D supplement, is a good way to make sure you’re getting all the nutrients you need to be healthy."
  • Are chemically treated/heavy foods bad for you?
    • No notable claim is quoted.
  • Does an "apple a day keep the doctor away"?
    • The title asks a different question than any of the four questions in the question body. Only the title of the question challenges a notable claim. This question is too broad.
  • Is mycoprotein (Quorn) safe for human consumption?
    • While the title is vague, the claims being challenged are clear: "CSPI claimed in 2003 that it "sickens 4.5% of eaters". The manufacturer disputes the figure, claiming that only 0.0007% (1 in 146,000) suffer adverse reactions". These are mutually exclusive claims. The asker asks which is true. It is not a vague claim about healthiness.
  • Is decaffeinated coffee bad for health?
    • No notable claim is quoted. Had the asker chosen one of the claims from the Wikipedia section he linked to, he could have chosen "Consumption of decaffeinated coffee appears to be as beneficial as caffeine-containing coffee with regard to all-cause mortality", or "In women, consumption of decaffeinated coffee significantly decreases all-cause mortality with an odds ratio of between approximately 0.8 to 0.9 with a consumption of 1 cup to approximately 6 cups per day, compared to those who drink less than one cup per month", or "In men, these beneficial effects are not as great, yet show a tendency toward significantly less mortality for those that drink more than 2 cups per day compared to those that drink less than one cup per month", and many others.
  • Do "probiotics" have health benefits?
    • While the title is vague, the claim being challenged is clear: "Consuming certain probiotics can help strengthen the body's natural defenses by providing a regular source of “friendly”bacteria to the intestinal tract, helping to correct an imbalance of the intestinal microflora and optimizing the functioning of the digestive tract’s immune system and intestinal lining", and the accepted answer addresses this directly. This is a good question.
  • Is eating eggs bad for me?
    • The title is vague, and while the actual question is more specific, no notable claim is quoted.

I think the following additional criteria should be considered when looking at these questions:

Specific Illness/Benefit

Generally studies look at a particular condition. For example, they might examine whether cucumber triggers asthma. As such, it is very difficult to prove that cucumber is healthy - but easier to show there is no evidence it causes a particular disease. (Yes, epidemiological studies could point to high cucumber consumption as being correlated with higher mortality but it is difficult to show causality.)

We should accept claims that specify a particular medical condition that the foodstuff is said to cause or cure, but should consider closing questions that leave it open-ended as "healthy" or "unhealthy".

The Dose Makes The Poison

Without a clear indication of how much of a substance is being consumed, it is largely meaningless to say it is healthy. We should accept claims that specify how much (e.g. 8 glasses of water per day), but should consider closing questions that are open ended (e.g. is eating beetroot healthy?)


Compared to a balanced diet, eating exclusively hamburgers is likely to increase mortality. Compared to starving, eating exclusively hamburgers is likely to decrease mortality.

For people with cardiovascular risks, eating sodium-rich foods is dangerous. For youths, it may be fine.

Salted roasted peanuts may generally be considered harmless...

... unless you have an allergy

... or cardiovascular risks

... or obesity

... or they has been contaminated

... or they have been burnt

... or they are being served by a bar to encourage overconsumption of alcohol

... or they are not being consumed in moderation as part of a balanced diet.

It isn't appropriate to declare peanuts to be unhealthy (unless there is another risk I am unaware of) but nor is it appropriate to declare them healthy.

We should only accept claims that specify the audience the advice is aimed at, and it is clear what the food is replacing in the diet - i.e. what would the 'control' diet be?

Note: Good answers should address the size of the risks to allow better decision making. I accept that chocolate cake is not the healthiest choice on the menu; I consume it in moderation after accepting these risks.

  • 1
    I disagree. Food agencies determine if foods are safe for human consumption as a day-to-day thing. Surely they provide a good reference to answer these question decisively (even without specifying the disease, the dose, etc.)
    – Sklivvz
    Sep 6, 2013 at 18:33

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .