Concentrated High-Calorie Goo

While the idea of the Food Pills has been banished to Zeerust, the idea of ultra compact food lives on in more recent science fiction. Since writers have woken up to the fact that humans are biologically conditioned to like eating (and in fact need a certain amount of "bulk" to their food), the "all in one" meal is no longer treated a luxury of modern technology, but as an unpleasant necessity. Now the "food" of the future takes the form of a goo or gel that's either colored a dull grey or disgustingly artificial bright primary or secondary color, and its taste is either non-existent or poor. If Concentrated High-Calorie Goo fulfill moisture needs as well depends on the work, though it generally will not.

In Dystopian settings, this bland gruel may be the only thing humans (or, at least, those of lower status) have ever eaten in their lives. In less dystopian settings, such goo can still show up, but it will be as emergency rations, for situations with minimal storage space, or part of the diet of aliens with minimal, different, or no sense of taste.

The unholy spawn of Future Food Is Artificial and If It Tastes Bad, It Must Be Good for You.

Anime and Manga

 * The Super Gel Dero Doro Drink from Needless is an energy drink that contains 5000 kilocalories. Eve often drinks this beverage due to how her Fragment uses a massive amount of calories as a drawback.
 * Crayon Shin-chan Gaiden: Alien vs. Shinnosuke has a delicious goo dispensed in a specific chamber that when digest can fatten up the prisoners.

Comic Books

 * The Kymellians of Power Pack (which later issues reveal are in a self-created dystopia of spiritual and empathetic decadence) eat a rainbow-colored dust as their primary substance, and their sapient ships can provide it in ample quantity. While all Kymellians insist it's fine, humans can only describe eating it as comparable to trying to consume "sawdust".

Fan Works

 * For most parts on Astral Journey: It's Complicated, Emma was fed some kind of goo via feeding tube connected to her stomach. This is justified as she wasn't able to eat while she was in a coma and after waking up because of her jaw was wired, as it healed.

Film

 * The various varieties of Soylent in the film Soylent Green are basically this, ostensibly made from soybeans and lentils (hence the name). In the original Harry Harrison novel Make Room! Make Room!, on the other hand, soylent was just a variety of textured plant protein used to make mock meat products, instead of a paste-like ration.
 * There are two different goos within The Matrix series that have different sources. The first would be how the people in pods are fed recycled biomatter made from human corpses. The second is rations that the resistance consumes that's a white and semi-translucent slime made of a single cell of protein, vitamin, and mineral.

Live-Action TV

 * In Travelers, the future has people survive on some chunky goo for sustenance due to how Earth's environment couldn't sustain proper life from disasters in the past.

Tabletop Games

 * The various Star Wars RPGs have at least one type of rations described this way.
 * Starfinder has future MREs in its core book, but also has "field rations" that weigh a seventh as much, cost a seventh the price, and take up a seventh the space, but are described as unpleasant to survive on.
 * Among Warhammer 40,000's dystopian hive cities and the Imperial Guard, one of the most prominent foodstuffs is Soylens Viridians, which is, indeed, composed of people and whatever other random biomass they have. Space Marines primarily eat Triglyceride Gel and Amino-Porridge.

Real Life

 * Fameal is a ground mixture of grain, bean, sugar, oil, vitamins and salt that is used for food aid and animal feed. It is edible raw and typically looks like a finely ground grain, but it can be made into a porridge, which is a perfect match for the goo description, or a bread with relatively little work.