The method of doubt has already delivered the verdict that I can't be sure I have a body, and nothing in the cogito undermines this conclusion. This leaves what Descartes calls
' the attributes ... assigned to the soul' (Descartes, Meditations, 2; Cottingham, Descartes - Selected Philosophical Writings, Cambridge, 1988, CUP, p.81.) e-text
Surprisingly, he lists among these nutrition and movement. The understanding is presumably that movement is the power to initiate movement. Descartes thought this was not in the body as body. I.e. mechanical things cannot originate action.
Likewise nutrition is the power to assimilate material from the environment so as to permit growth and repair in an organism. This power is not in 'body', thinks D: it is in what is associated with body in an organism, namely the soul (without saying anything else about the soul at this point).
Both nutrition and movement serve the body, however, - as the powers to move, and to grow. Without the body they don't make sense. So neither belong to the 'I' that is left after the programme of doubt.
[Notice here the Cartesian concept of body.]
Something similar applies to sense-perception. Descartes says simply that 'this surely does not occur without a body'. (Descartes, Meditations, 2; Cottingham, Descartes - Selected Philosophical Writings, Cambridge, 1988, CUP, p.82.) e-text
END