Is it possible to find the feature importance of an aggregate feature from the corresponding independent features in a linear model?

I have a model to predict energy consumption in a food processing plant. Different food products are produced in the plant. My model is given as

Energy consumption(Kwhr) =
alpha0 +alpha1(Food Item A produced in Kg) + alpha2(Food Item A produced in Kg)
+alpha3(Food Item C produced in Kg)+....+Other variables 

Since different product categories have different energy intensities, I would like to add that detail to the model. Can I derive the feature importance of the Total production on the energy consumption from this Linear model?

Total production = Food Item A produced in Kg+Food Item B produced in Kg+Food Item C produced in Kg