Question: What food takes the longest to digest?

Rachel Edwards-Stuart answered on 13 Mar 2013:

Foods that are made up of long chains of molecules, or have complex structures, take the longest time to digest. A simple sugar molecule is very small and easy to digest, so it provides you with energy quickly. Starches are made up of long chains of sugar molecules, and these sugar molecules need to be broken down first before they can be absorbed by the blood, so they release energy more slowly. This is why having porridge for breakfast gives you a slow release of energy, but keeps you feeling fuller for longer. With sugar for breakfast you get an instant energy hit, but it also disappears quickly leaving you hungry. Fibre is such a complex molecule that it is never broken down – it passes through you without being digested at all. That’s why it is important to have lots of fibre in your diet – to keep everything moving through your gut.