I came across the following list. "Top 10 biggest brain damaging habits". Although they're all interesting "food" for skepticism, I will focus on #1, because I find this a peculiar claim. Some other claims are already on this site, e.g. about working your brain during illness (unanswered though!).

"Top 10 biggest brain damaging habits"

  1. No breakfast. People who do not take breakfast are going to have a lower blood sugar level. This leads to an insufficient supply of nutrients to the brain causing brain degeneration.

This question is also about breakfast, but does not specifically address the issue of the brain.

  • 2
    yeah i saw that in my feed. commented: "citations or it didn't happen"
    – DForck42
    Jan 22, 2013 at 21:31
  • 21
    Suprising that "Reading list of Top Ten things" does not rate as a "brain damaging habit". Jan 22, 2013 at 22:28
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    Taking cocaine and drinking huge quantities of alcohol are two habits that would be clearly worse than skipping breakfast. My point is that nobody takes lists like this as being scientifically proven ordered lists of the absolute worst things. It's not even clear that the list is intended to be in order. Jan 22, 2013 at 22:59
  • 4
    I like that "Air Pollution" is listed as a habit.
    – Kip
    Jan 23, 2013 at 19:36
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    @Kip I'm a habitual breather :)
    – Tacroy
    Jan 23, 2013 at 23:20

1 Answer 1


This question is hard to answer because it includes the wrong assumption that dietary calorie restriction damages the brain. This assumption forms the basis for the assertion that "lack of breakfast" is "brain damaging".

So I would answer it in two steps.

Step 1. Is dietary calorie restriction detrimental?

Much to the contrary, there is ample evidence suggesting that calorie restriction (CR) increases general health, and lengthens life.

I quote the paper below on studies with humans:

This evidence consists of the finding that risk factors for atherosclerosis and diabetes are markedly reduced in humans on CR. Humans on CR also show some of the same adaptations that are thought to be involved in slowing primary aging in rats and mice. These include a very low level of inflammation as evidenced by low circulatory levels of c-reactive protein and TNFα, serum triiodothyronine levels at the low end of the normal range, and a more elastic “younger” left ventricle (LV), as evaluated by echo-doppler measures of LV stiffness.

From the same paper, some anedoctal evidence:

Okinawans, because of poverty, were so severely calorie restricted that their growth was stunted. However, public health measures and quality of the diet on Okinawa were sufficiently good to prevent the high prevalence of nutritional deficiencies and infectious diseases present among the poor in many third world countries. It is interesting, relative to the possible effects of CR on human longevity, that there are more centenarians per 100,000 people in Okinawa than in other parts of the world including the USA and Western Europe (Chan et al., 1997).

And from the one on brain effects of CR:

These beneficial effects also extend to the maintenance of brain cognitive functions at later age and to the prevention, at least in rodents, of brain senescence and associated neurodegenerative disorders.

Step 2. Is skipping breakfast detrimental?

Yes, but not because calorie restriction is generally bad. Some studies (see below) suggest that skipping breakfast might lead people to overeat later in the day, which in turn would cause obesity.

On whether this is bad for the brain,

The evidence indicates that breakfast consumption is more beneficial than skipping breakfast, but this effect is more apparent in children whose nutritional status is compromised.


Based on this evidence, I believe there is no direct causal relationship between skipping breakfast, low blood sugar and brain degeneration (as the original statements implied).

  • 1
    Welcome to Skeptics!. In the final sentence, you are making a big assumption that begs the question. Even if you are on a calorie-restricted diet, it is plausible that consuming those calories at the start of the day makes a difference. See this answer for an example study showing this.
    – Oddthinking
    Sep 4, 2013 at 0:46
  • @Oddthinking, I made a major edit to address skipping breakfast directly. I am not aware of studies that test calorie restriction at the start of the day, though. The study you quote is about excess dietary fat, while my answer refers to decreased dietary calorie intake. Results from either studies are not directly comparable, and I believe yours is not relevant to this question.
    – dmvianna
    Sep 4, 2013 at 2:19
  • Thanks for the edits. I think they have improved the answer. I agree that the study I quoted doesn't undermine the benefits of a restricted calorie diet. I quoted it to demonstrate that, yes, the timing of calorie consumption can affect physiology. Merely calorie-counting doesn't cover everything. The study I quoted isn't sufficient to answer the question, but justifies its plausibility.
    – Oddthinking
    Sep 4, 2013 at 5:52
  • Can I suggest something for you guys to consider? This article seems to claim that skipping breakfast is not good in all aspects: ncbi.nlm.nih.gov/pubmed/15883552 Thanks for your answer, btw! Mar 18, 2015 at 9:54
  • @LuccaMordente, the question is about permanent brain damage, not about cognitive performance. Obviously hunger does not help concentration.
    – dmvianna
    Mar 18, 2015 at 10:05

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