In Ayurveda - the human body is called as 'Sarira'.
If you see the root meaning of the word 'Sarira', it goes like
"that which keeps dying every moment" 
or "that which keeps eliminating waste every moment".
By going with this definition, it means 
The efficiency of your waste elimination 
is the efficiency of your health and your body.
If there is a block in the flow of elimination of waste 
then there is a block in your energy levels.
So Ayurveda says there are two types of diseases.
Disease because of Over Nutrition 
and disease because of Under Nutrition 
And what it says is disease because of 
over nutrition is more difficult to treat
than the disease of under nutrition,
because eliminating waste is more difficult than 
giving/providing nutrition to the body.
and thats why Ayurveda came up with a 
treatment methodology called as Panchakarma 
which specailizes in waste elimination intensively from our body 
in a cellular level.