Areas › Your body › Food, caffeine and fuel
Caffeine buys about half an hour of sharper focus and takes the payment out of your sleep. It is a decent tool for a particular hour, and using it in place of treatment usually leaves you worse off across the day.
Four cups a day and upwards starts producing insomnia, irritability, tremor, an unsettled stomach and a racing heart, and a few people go sleepy on it rather than alert. In anyone whose sleep is already fragile, the attention lost tomorrow costs more than the alertness bought today. It is a particularly poor swap for a child's medication, since children can end up in withdrawal.
Qur’an and Sunnah
Do not be extravagant: God does not like extravagant people (Quran 7:31). The same verse permits eating and drinking, so what is warned against is the amount rather than the cup.
۞يَٰبَنِيٓ ءَادَمَ خُذُواْ زِينَتَكُمۡ عِندَ كُلِّ مَسۡجِدࣲ وَكُلُواْ وَٱشۡرَبُواْ وَلَا تُسۡرِفُوٓاْۚ إِنَّهُۥ لَا يُحِبُّ ٱلۡمُسۡرِفِينَ
Children of Adam, dress well whenever you are at worship, and eat and drink [as We have permitted] but do not be extravagant: God does not like extravagant people
Qur’an 7:31read it in the library
Translation: M.A.S. Abdel Haleem, The Qur'an, Oxford University Press, 2004.
What the research says
As a short term aid it does have decent evidence. A Cochrane review found caffeine reduced errors and injuries in shift workers compared with no intervention. Notice what that does and does not say: it helps performance through a stretch of unavoidable tiredness, and it says nothing about treating a condition or about what it costs your sleep afterwards.
Ker K, Edwards PJ, Felix LM, Blackhall K, Roberts I. (2010). Caffeine for the prevention of injuries and errors in shift workers.. The Cochrane database of systematic reviews doi
Strength of evidence: one line of research. A single study, or a theoretical account.
Why it works
Caffeine blocks the signal that tells you you are tired, which is not the same as improving attention, and the sleep it costs comes off tomorrow.
When not to
Stopping suddenly after heavy use brings headaches and low mood, so taper over a week or two rather than quitting dead.
This one is still a draft. It is waiting on a scholar and a clinician to read it before it is published.
Near this one
Very low vitamin D produces fatigue, low mood and a flatness that looks exactly like depression, and it is not part of routine bloods in most places. If you have never had it measured, it is a fair thing to ask for.
The studies linking pesticide levels to ADHD are tangled up with income, since families least able to buy organic differ in plenty of other ways too. If organic food is affordable for you, fine. If it is not, you are not failing your child.
Most eating advice quietly assumes a budget. Fresh food is expensive and does not keep, so a household relying on food assistance ends up buying what lasts, and what lasts comes in tins and packets.