Slow digested meals while keep eating

Question

I'm not sure if this is the correct site to ask this

Let's say that I take a casein protein shake in the morning let's say 8 am, this will be slowly digested so I will have nutrients during several hours

I have a medium-fast metabolism

So the casein shake it's supposed to last for 8 hours

So I take my second breakfast at 10 and then my lunch at 12

So by the time I have my second breakfast and lunch the casein protein is supposed to be in the process to be digested

So what happens?

Does my body need to wait until the casein protein is fully digested to be able to digest something else?

or

Does my body can start digesting my breakfast and lunch like at the same time while the casein protein is till being digested?

In other words does digestion work like a Queue in such a way that it has to digest the first meal before digesting the next meal or can it be digested in parallel

(Yeah I'm a geek developer jaja)

I'm asking this because since I'm taking the casein protein in the morning I feel less hungry than before and this scares me because I feel I wouldn't be able to reach my calories goal

Answer 1

No, your stomach is not like a queue-dequeue data structure.

As food enters your stomach it gets disolved and decomposed by a number of enzymes that all work on micro- and macro-nutrients in different ways. Depending on the size, structure, and in some cases your genetic make-up these will all be processed at different speeds in different ways.

On top of this, some nutrients are absorbed in different places throughout your digestive tract. So, while they might be broken down in the stomach, they won't be absorbed until they are in the small intestine after other enzymes and digestive fluids have been secreted.

Your body takes between 24-48 hours to excrete the waste from a meal, so given two meals eaten within a few hours of each other, it is very difficult to say which will be digested first.

If you need to meet a caloric goal, and are having trouble, look for easy to inject, high-calorie options. Drinks are especially good as they can be high-calorie, with relatively little bulk. Whole-fat milk, juice and protein drinks are all good options for high-cal drinks, depending on your macro requirements.