If you look at pictures from when you were a baby and you look at yourself now, you will see a few changes. The main change being that you grew.
We tend to think that we are born with a body and that is the same body that you will one day grow old in, just older and bigger, but still the same but the truth is that parts of your body 'renews' itself every now and then.
Most of the cells in your body would have died and new ones would have formed in their place, so if you do not look after yourself, your body will 'rebuild' itself but in a worse version of the body you had. If you eat healthy and stay fit, the new cells will be healthy and you will have a 'new' healthy body.
It is your decision if you want to 'rebuild' your body by eating junk food or sweets and cake or if your want to do it by eating healthy foods like fruits and vegetables.
It is so much easier for the body to repair itself if it has enough vitamins and nutrients and that you will only get from a healthy lifestyle.
If you cut your finger and after a day or two the cut heals, that is proof that new cells 'regenerated' (were formed) to fix the cut. In the same way in many places in your body the cells will regenerate to form different cells and organs. Lets have a look at a few:
The liver, stomach and brain are all very important organs that we need to keep us alive. Even though your brain cells lasts a life time, there are some new nerve cells that will form.
The liver is an organ that you can give half of it away while you are still alive to somebody that needs a liver transplant. The wonderful thing about the liver is that it grows again and in a short period of time it would have totally 'regenerated' itself. The main function of the liver is to remove the toxins from the body and if your liver never grew new cells, you would end up with a very dirty liver that would stop working very soon.
The lining of the stomach can easily be damaged by the food you eat and the hard work it does to digest the food, but if you just give it a chance it will heal itself.
The skin is not only the largest organ of the body, but it is also the one part of the body the 'regenerates' very fast. Have you ever burned in the sun and then your skin starts peeling off? Luckily we do not have to worry that we will be walking around without a skin, because underneath the top layer, the new skin has already formed.
The red blood cells are very important in our bodies, because it is that little thing that carries the oxygen through our body. They do not live forever and after about 4 months the old red blood cells are send to the liver, where the iron will be taken out and placed into the newly formed red blood cells and just like that you have new blood in your body.
If you have ever broken a bone in your body you would know that it took a few weeks in a cast or a 'moon boot' so that it can heal. Again the reason why the broken bone will grow together again is because of new cells that are formed. Even if you have not broken a bone, it still 'regenerates' and produces new bone tissue.
There is a lot of pollution like smoke around us. We inhale gasses that we cannot see and a lot of them are poisonous. The lungs has a very important work, because what other organ will inhale oxygen for our bodies?
The 'bubbles' in the lungs where the oxygen and carbon dioxide is taken to during breathing is called the 'alveoli' and they are important and luckily we also get some new ones every year or so and the outside of the lungs will renew every couple of weeks.
Don't you think it is wonderful how we were created and how our bodies work? So take some time and realize that to keep your body in a good working condition and making the whole process of making new cells easier, the best thing that you can do for your body is make sure it gets enough vitamins and nutrients and live a healthy life.
Resources and for extra information
http://www.nytimes.com/2005/08/02/science/your-body-is-younger-than-you-think.html
https://livelovefruit.com/how-your-body-rebuilds-itself-in-less-than-365-days/
