Ensure / fortisip / Optifast (as seen in the video in the submutted link, where the doctor tells him that liquid total food replacements have been available for decades) / etc etc etc.

Here's Abbott Nutrition http://abbottnutrition.com/

Here's Nutricia https://www.nutricia.co.uk/fortisip//

It's frustrating that this question is asked, and answered, every single time Soylent is mentioned, and people then dishonestly say that these products are somehow not meant to be used as a sole source of nutrition, even though that's how they're regulated and sold.

Yep. My mom got all her nutrition from Ensure for a couple months after stomach surgery. She lived.

Thanks, I'm going to try some Ensure.

I've also been drinking Carnation Breakfast Essentials occasionally but I'm not sure how much different it is from drinking a glass of chocolate milk and a multivitamin.