Basal metabolism—the energy our body needs just to keep us alive—typically burns around 1,650–1,800 kcal a day for men and 1,300–1,600 kcal for women.

Since basal metabolism accounts for most of the calories we burn each day, helping the body rely more on fat as a fuel can have a much greater impact than simply adding another hour of walking.

And yes—even while we’re fast asleep, our body continues to burn energy because our heart keeps beating and our lungs keep working.