Supper

Every night your body repairs itself, for free. It starts once your stomach is empty.

Two or three hours between supper and sleep is enough.

What the empty stomach starts

Digestion takes work. While food is coming in, your body sends blood to the gut, raises insulin and gets on with breaking the meal down. The repair work has to wait its turn.

In 1992, in a laboratory in Tokyo, Yoshinori Ohsumi starved yeast cells and watched them under a microscope. Inside them, rubbish was piling up in the vacuole, which is the cell's own bin, and something was taking it apart. He had found the machinery. In 2016 he won the Nobel Prize in Physiology or Medicine for it.

He called it autophagy, which means self-eating. Cells take apart their own worn-out parts and build new ones from the pieces. This is how your body keeps replacing itself.

Autophagy works best when no food is coming in. Nobody knows yet exactly how many hours it needs in a person, so treat any precise number you read with caution.

The hours between supper and breakfast are the night shift. Your body stops being a kitchen and becomes a repair shop, clearing the day's wreckage cell by cell. Give it an empty stomach and it has all night to work.

Same food, different clock

Nothing has to come off your plate. It is the hour that matters, and one experiment shows it clearly.

A team at Brigham and Women's Hospital in Boston fed the same volunteers twice. Every meal was weighed to the gram. Sleep, light and exercise were kept the same. The only difference was that the second time, every meal came four hours later.

Eating earlier kept their appetite steadier. Two hormones run hunger: ghrelin asks for food, leptin says you have had enough. On the early schedule those two stayed in better balance.

The early schedule did two more things: people burned more of their food during the waking day, and their fat tissue was busy breaking fat down rather than storing it. Autophagy was one of the processes that shifted.

The study came out in Cell Metabolism in 2022. Everyone in it was overweight, so we do not know yet whether it holds for everybody.

Morning helps in the same direction. Your body handles sugar better early in the day, so the same plate is easier work at eight in the morning than at ten at night.

None of this is fasting. Twelve hours between supper and breakfast is how most of Europe ate for centuries, before kitchens had electric light.

How to close the kitchen

Three things, and none of them cost anything.

• Move the meal, keep the meal. The same supper, one hour earlier. Eat all of it. You are only changing the time.
• Eat well at that meal. Enough protein and fat at supper keeps you full all evening. Then the gap afterwards is easy. What I eat is in the food principles, and the packaged things worth trusting are in the Forbidden Fruit directory.
• Let tea close the evening. Herbal tea with nothing in it, or a glass of water. A warm cup is a nice way to end the day.

If nine o'clock is the only time you can eat, two hours is plenty. Pick the gap you can actually keep.

You will know it has worked when you wake up hungry.

It works best alongside the other three: darkness, air and a cool room.

So close the kitchen two or three hours before bed, let the last thing of the evening be tea or water, and let the dark hours do the work they were built for. You are not skipping a meal. You are booking the oldest spa treatment there is, the one your own body performs on itself, for nothing, every night you allow it.