Oscar-winner Octavia Spencer says when she sleepwalks she heads for the fridge, and actress Anna Kendrick admits she once used her phone to make a cinematic masterpiece of a salad she put together while sleep-eating.

Sleep-related eating disorders may demonstrate how closely rest and refreshments are linked, but they're not what researchers are talking about in a study that shows "sleep is as important as food."

That statement comes from the study's senior author, who led a team that uncovered why we sleep and how it nurtures brain health.

This research published in Science Advances found that up to age two and a half, the brain is using the REM sleep stage to build new neuron connections.

After that, the brain shifts from mostly REM sleep to mostly non-REM sleep, and although some new neural connections can be made throughout life, the work that goes on nightly is focused on repairing damage and taking out the trash. Without that happening, you set yourself up for neurological diseases, diabetes, and obesity.

The repair work can't go on without good quality sleep: seven to eight hours nightly, in a dark, cool, quiet room with no digital devices.

If that eludes you, upgrade your food choices (no added sugar or too many saturated fats) and manage your tension.

You can use a self-massager, get a shoulder rub from your partner, or meditate for 10 minutes before bedtime.

A new study in Scientific Reports says such short-term treatments can effectively reduce psychological and physiological stress. Then sleep can follow — and your brain can start housekeeping.