Yeah, while scientifically calories matter, realistically and applied they often times do not.
The problem is the body is adaptable and a calorie while a calorie is not used/transported the same way.
I’ve found those who eat meat, eggs, cheese, and/or milk tend to require caloric restriction and calorie counting (watching sugars and fats) while if you have soylent or other plant-based foods, assuming they’re not disgustingly refined garbage, you can eat till you’re stuffed and generally stay at a healthy weight.
Studying into this gave me reasons for this, and it’s excessively complicated and in short it’s due to hormones, not particularly in the food, but what your body behaves like with different foods, compounds, and ratios.
While I do not personally like high-fat, which is one reason I veered away from soylent for some time, there’s nothing wrong with it unless it’s rancid or grouped with excessive protein or sugar.
For soylent, since you drink primarily it it sounds like, as long as you don’t go and drink some soda everyday the fat will have no real affect. On the other side of the coin, me, who has low-fat and soylent as <20% of my diet I can have copous amounts of sugar, including from refined foods, and have no issue due to the way blood sugars levels behave in relation to fat/protein.
It’s a shame more people don’t listen to their bodies though. If you feel tired, NEED caffeine, feel weak, etc, there’s likely nothing wrong with your diet its-self but rather you not eating enough of it.
To clarify though, if you do high intensity activities, like cycling for sport or running long distances above 5.5-6mph then you may need a little more carbohydrates than soylent provides, however if this is the case you’ll definitely notice as you’ll get extremely fatigued all of a sudden and lose performance, then the moment you eat you’ll perk up. To have this issue you usually have to be eating 4000+ calories a day to supplement the exercise though, so it likely doesn’t apply.