Large, I am having diet cooked and restricted (7)
I believe the answer is:
limited
'restricted' is the definition.
(similar in meaning)
'large i am having diet cooked' is the wordplay.
'large' becomes 'L' (eg in clothes sizes).
'i am' becomes 'I'm' (contraction).
'having' means one lot of letters go next to another.
'cooked' indicates anagramming the letters (letters cooked into a new form).
'diet' with letters rearranged gives 'ited'.
'l'+'im'+'ited'='LIMITED'
'and' is the link.
(Other definitions for limited that I've seen before include "Restricted in extent" , "Narrow" , "Constrained" , "Confined within bounds" , "Finite - type of company" .)