I've been researching this and found it is quite complicated. The amount of air in the finished product (overrun) is determined by several factors, the fat structure, emulsifiers, and stabilizers in the mix as well as the machine itself and how it whips the mix during freezing. It's also important that the air cell wall is strong enough to last until consumption. Most all home machines have no way to control the mechanics of the whipping or the speed so it's all about the mix you put in. Things you have control over that affect this are:
- temperature of the mix
- the type and quantity of fat
- emulsifiers - egg yolk solids, buttermilk solids, nonfat dry milk, other chemical names you likely don't use at home
- stabilizers - gums and such that you likely don't use at home
The goal is for water, fat and air cells in the finished product to be as small as possible. Big ice crystals taste gritty, big globs of fat separate and make it seem greasy, large air cells make it seem too foamy.
My conclusion: Unless you plan to study the chemistry of ice cream making (take the PSU week long short course), get a good recipe, follow it to the letter and make adjustments in very small increments. It does not take much to affect the molecular interactions. If your machine seems to be making the ice cream too foamy or too thick, find another recipe because it's a combination of the machine and the recipe that affect overrun an there is likely an ideal recipe for your machine.
The good news is all the trial and error involved is yummy.