Your body

Put an actual number on it: how many coffees, teas, energy drinks and colas in a normal day. Without that number, your sleep problems, your anxiety and how well a medication is working are all being read against an unknown.

People underestimate this, partly because it feels embarrassing and partly because a large takeaway cup is often two or three servings. Count across…

Stimulants sharpen focus in almost anyone, so responding well to one does not confirm you have ADHD. The diagnosis comes from your history and how you function, not from a trial of tablets.

This cuts both ways. Someone can be handed a diagnosis on the strength of a good response, and someone else can be doubted because their response was…

Food and movement are powerful, and hardly anyone keeps them up as prescribed. So the question is not what works best on paper. It is what you will still be doing in six weeks.

Roughly a third of people follow a prescription exactly as it is written, and keeping to a diet or an activity plan goes worse than that. Which means…

Pick one small change and leave the rest alone. A full overhaul asks the most of you at the point when you have the least to give, and it usually collapses in the second week.

One change, small enough to be almost boring, kept for a month. Then another. It feels slow while you are in it, and it is the version that tends to…

Working out what you have comes before choosing what to take. The right remedy for the wrong condition is still the wrong remedy, however good the remedy happens to be.

The health food shop route usually starts with a self diagnosis, and that first step is the one worth slowing down. St John's wort will do nothing…

Supplements are regulated as food rather than as medicine. Nobody checks strength or purity before a product goes on sale, and the main rule is that the packet cannot claim to treat a disease.

Most people assume the opposite, that anything on a pharmacy shelf has been through some kind of approval. Regulators here generally act only once a…

When researchers ran DNA testing on 13 herbal products, only 2 contained the plant on the label. Three had none of it at all, and several were padded out with rice, soy or wheat that nobody had declared.

The obvious problem is paying for something you did not get. The quieter problem is the undeclared filler, which matters a great deal if you avoid…

A second study, this time of 44 products, found only about half were authentic. Roughly six in ten were mislabelled, three in ten contained a substituted ingredient, and one in five held contaminants or fillers.

One study of this kind is a story about some bad batches. Two independent studies finding the same thing is a description of how the market works.…

If you are going to buy supplements, look for an independent verification mark: USP Verified, NSF, or a product tested by ConsumerLab. It is the nearest thing available to the check that regulators do not carry out.

Those schemes test identity, strength, purity and how a product was made, and manufacturers pay to take part voluntarily. There are different tiers,…

St John's wort can cut the effectiveness of the contraceptive pill by around a third. If you take both, that is worth knowing today rather than finding out later.

It speeds up the way the liver clears certain drugs, so the pill is not the only thing affected. Warfarin, some HIV medicines, ciclosporin and a…

Several herbal products change how fast the liver processes medication, which can leave a prescribed drug either weaker or stronger without a single change to the dose.

This is often why a supplement looks like it caused a relapse or a sudden run of side effects. Nothing about the prescription changed, so the pattern…

Two to be careful with in particular. Yohimbe reliably ramps anxiety up, so much so that it has been used in research to bring panic on, and kava is a sedative that stacks with alcohol and with sedating medication and has damaged livers at higher doses.

Kava has been restricted or banned in several countries over liver harm, which tells you how seriously that risk is taken. Yohimbe is a poor choice…

You cannot patent a plant, so there is little commercial reason to fund expensive trials of one. When you read that a herb has no evidence, that often means nobody paid to look rather than that somebody looked and found nothing.

Both halves of that need saying. No evidence is not proof of no effect, and it is also not permission to assume one. It leaves you with an open…

Some of these do have real evidence behind them. St John's wort has repeated support in mild to moderate depression, SAMe and methylfolate have reasonable backing as additions to treatment, and omega-3 has looked weaker in the larger and better run trials.

That last part is worth sitting with, because it is what usually happens. An early promising effect shrinks as trials get bigger and better…

If you want to use herbal remedies, two things carry most of the risk. Make sure whoever prescribes for you knows what you are taking, and buy from a source that has been independently tested.

That is a short list on purpose. Nearly all the harm in this area comes from an interaction nobody knew about or a product that was not what it…

Herbal products are rarely covered by insurance and they add up quickly. That cost belongs in the decision, particularly when you cannot be sure the capsule holds what it says.

Money spent here is money not spent elsewhere, and often the alternative is a treatment that is covered and has been tested. Nobody is telling you…

What you feel does not stay in your head. Emotional states register in the body's immune signalling too, which is one reason a long stretch of unspoken distress can leave you physically run down.

This is not a claim that you can think yourself well or ill. It is closer to saying the body keeps a tally. If you have been carrying something heavy…

Water, sleep, food and digestion are not the boring preamble to the real work. When those are running badly, everything else you try has less to work with.

It can feel almost insulting to be asked about breakfast when what you carry is so much bigger than breakfast. But a body short of sleep and short of…

Health advice usually assumes a kitchen, a fridge and money for the week. If you are working with less than that, the answer is not to try harder at the advice. It is to shrink the plan until it fits what you actually have.

A plan you cannot keep does more than fail. It quietly adds to the pile of evidence that nothing you do makes any difference, and that pile is heavy…

A physical symptom is not a free floating fact. Read it next to what your life has actually held, the early parts included, and it often makes more sense than it does on its own.

This works in both directions. It stops you treating a body complaint as something random that landed on you, and it stops you treating it as a…