Healthy living

Where to start, if you change only one thing

Sleep. It is the lever with the fastest and widest effect: mood, appetite, concentration, tolerance of stress, the wish to move — all of it depends on sleep. One extra hour, regularly, does more than any supplement.

Three traps recur across all of them. The first is the over-ambitious goal, abandoned within a fortnight. The second is trusting whatever is being sold: a supplement, a device, a course, a diet named after its inventor. The third is treating the symptom without looking at what produces it — caffeine for tiredness, a screen for boredom, a diet for anxiety. The Drugs and addiction section deals with that last point.

The pages in this section

These subjects are handled together because they hold together: sleeping badly disturbs appetite, not moving degrades sleep, eating anyhow is tiring, and the skin records everything else. Acting on one lever gives disappointing results; acting on two is often enough to change everything.

What the advice going round is actually worth

These four areas share one feature: they are saturated with contradictory recommendations, and it helps to know where a claim comes from before following it. Three simple markers sort most of it.

• A solid recommendation rests on trials, not on a mechanism. “This molecule acts on that receptor” is not evidence that a supplement works in humans: the great majority of plausible mechanisms do not survive a clinical trial.
• Be wary of advice that comes with something to sell. When the same page recommends a practice and offers the product that goes with it, the recommendation is not independent.
• A spectacular effect announced on a small sample almost always disappears when the study is repeated at scale. That is as true of diets as of exercise programmes.

Three expensive misconceptions

“I will catch up on sleep at the weekend.” You recover part of the debt, not all of it: alertness returns, but the effects on metabolism and mood persist. A regular bedtime does more than a lie-in.

“It only counts if you sweat.” The best documented benefits start very low, around a daily brisk walk. Regularity beats intensity for most people, because it lasts.

“It is natural, so it is safe.” St John's wort cancels the pill, grapefruit multiplies the concentration of several medicines, a slimming infusion can damage the liver. Tell the doctor prescribing for you about every supplement and herbal product.

Where to start, week by week

One change at a time, held for three weeks, beats five resolutions held for four days. An order that often works: first a fixed bedtime, then a daily walk, then either a real breakfast or an end to sugary snacking depending on which weighs more, and finally the dental check-up that has been put off for two years.