Did you ever notice you have to fill the tank of your car with gas from time to time?The engine creates energy to propel the car. Where else does the energy come from?
More labour doesn't mean more energy consumption. And producing the chemicals requires energy to.Environmentally friendly food production methods would require more labour as you would not be using chemicals to do the work for you.
If your formula were true:GDP = income = expenditure + savings.
Increased savings result in less economic activity thus slowing GDP growth or even reducing it.
GDP = expenditure + savings. If savings increase, then GDP increase

Increase savings would result in less economic activity only if you put your banknotes in a big hole and don't use it. But the money is used.