I think you could rather drink a mixture of a protein, vitamin, oil, enzymes, etc, shake today - and get the same effects, than wait for your enhanced meat product.
The energy limitation was also a leap, when apes (or whatever) started eating meat, and later humans (or whatever) started using fire to cook their foods. And then bigger, more thoughtful, brains could be sustained.
There really is nothing more to improve on that will give you better than marginal results from this point in time. And even then, you'd have to wait for evolution to take its course and produce (well, perpetuate) whatever DNA is required to produce a bigger brain over a millennium or even longer... Assuming that's even a trait that is capable of producing more offsprings than in those that don't have that trait.