Supposedly it takes anywhere from 30 minutes to 4 hours to digest food(depending on what you’re eating) so why does sugar give you an almost instantaneous surge of energy?

Question

Does it absorb straight away? Could it be the dopamine rush?

In: Biology

Answer 1

Food takes a while to digest because it’s not readily absorbable. Protein needs to be broken into its constituent parts (amino acids and short peptides) before it can be absorbed. Fat needs to be broken down in the stomach and further so in the intestine, as well as solubilized to facilitate absorption. Starch also broken down starting with your saliva, but sugar is even simpler. It comes in a much more ready to absorb manner (e.g. Sucrose is just two units linked together, glucose and fructose, and one enzymatic step is all it takes to break down, and it’s in your saliva). So it’s all about how complex the food is (fish for example has protein, fat and many other things, they need to be homogenized and digested through many steps before absorption) and where in your gastrointestinal tract it’s digestion and absorption begins. Some things like sugar and alcohol start digestion and absorption in the mouth. Others start digesting in the stomach and the intestine and get absorbed largely in the intestine (like fat). More enzymatic steps = more time. Further down the tract = more time (stomach takes time churning food around before releasing it to the intestine for example).