Check energy in sweet food (4,6)
I believe the answer is:
stem ginger
'sweet food' is the definition.
(ginger tastes sweet)
'check energy' is the wordplay.
'check' becomes 'stem' (both can mean to control or stop).
'energy' becomes 'ginger' (ginger can mean energy or vitality).
'stem'+'ginger'='STEM GINGER'
'in' acts as a link.
(Other definitions for stem ginger that I've seen before include "Plant root of a pungent spice" , "spicy ingredient" , "As food" , "Crystallised root" , "Merging set (anag.)" .)