It seems you'd get much less carotenoids from Soylent than just eating one tomato and one carrot per day.

Early recipe, and practically speaking, I don't know what the effects of one tomato & carrot a day would be! Rhinehart and the others have been on Soylent for, what, a year now? That's a long time for stuff to slowly accumulate. Most people don't eat a single vegetable that routinely. During the summer I eat 1 tomato a day (we grow ours) without glowing, but then I don't eat any tomatoes during spring/winter, which is disanalogous.