Digestion

Can you explain what happens to food after we eat it?

I would just look at it very simply.

When you eat food, the process of digestion breaks food down into it's respective nutrients as we discussed before. Carbohydrates into monosaccharides (single units of sugars), protein into amino acids and fats into fatty acids. This process starts when you actually chew the food, the food then travels down into the stomach through the esophagus where it is liquified.   When it reaches your small intestines, this is where the fun begins. Most of the digestion and absorption of the food occurs here in your small intestine. Digestive enzymes called lipase, amylase and protease act on fats, carbohydrates and protein to break them down into their nutrients for absorption.

Once the food has been broken down into their simple units, they are then absorbed into the blood stream for further chemical changes to make other compounds that the body needs, or for use around the body. Water and small lipids (fats) cross the
intestinal wall easily.   Some nutrients such as water and fat soluble vitamins need a carrier to take them across the wall. Other nutrients such as proteins and glucose move across the wall and into the blood stream by themselves but use energy to do so.

Once we've eaten the right types of food, does that mean that we always absorb it's nutrients?

Once the processes I've just talked about have been completed, your body has digested and absorbed the food. However, before the nutrients have actually entered the blood stream, the nutrients are not actually considered to have entered your body. So you can actually eat a whole lot of good food without absorbing it's nutrients.

You can ensure that you absorb the maximum amount of nutrients through a number of ways, but the major concerns would be to limit caffeine and alcohol intake, as alcohol can reduce the secretion of digestive enzymes that help to break
down food and caffeine can reduce your body's absorption of iron. Stress can also play a role in not allowing your body to absorb all the nutrients available to it. So if you want your body to absorb the maximum amount of nutrients, keep caffeine and alcohol intake to moderate levels. You can probably still have your morning coffee, but make sure that it is spaced at least an hour away from breakfast.