How light is light? Have you consulted a doctor?
They will come good in their own time. 7 months is still very young. Don't be under stress to compare your child with other children.
I have two children. The older one hated all kinds of food including milk and was super skinny until he started upper primary, while the younger one will accept anything we put in his mouth even at 6 months old.
Each child is different. Feeding should never be a growth milestone.
There is a kind of hunger called child not hungry but mother father very hungry.
As long as your baby is active doing baby things, don't worry about their feeding unless they are grossly under-weight and become lethargic.