Hello everyone, is it true that to make milk more nutritious you need …

Hello everyone, is it true that to make milk more nutritious you need to eat a lot and drink more milk? The child drinks milk well, we only give Gv, formula is not given at all, and here they keep telling me to eat a lot, a lot, a lot of food so that there is a lot of milk produced. If you eat little, will there be less milk? Is this true? I just want to eat less so that I get in shape, from the thought that I have to eat a lot for milk, I constantly feel like eating. ? And a flat stomach also wants to.