I used the Keto Fuel soylent for all my food for about four months on keto. It's much more delicious than Soylent (chocolate, cinnamon, vanilla). You add MCT oil and heavy whipping cream to it for the fats needed. Strongly recommended and you can even do local pickup in SF.
> Is something like Ensure allowed on keto? Its awfully convenient mid day.
A regular Ensure looks to have around 15g of sugars per serving, so it would not be conducive to a keto-type diet. For similar convenience there is a product called Ketochow - https://www.thebairs.net/ which I've found quite tasty.
15 grams of sugar is above the daily recommended sugar intake for adults. Recent research indicates that 10 grams daily is a more realistic limit for maintaining health.
You want to maintain a healthy amount of fat, usually 50-70% of calories from fat. If you eat too much protein, it is converted to glucose and you won't reach higher levels of ketosis.
Protein is a big scale that varies a lot - if you're working out or need it to sustain your muscle mass, then it's fine. It's the leftover protein that becomes a problem.
I have no affiliation with them and don't drink it often but I can tell you that it tastes awesome.