Weight works with a connected weight scale, if it's not connected...then it's a bit meh.
Calories and caffeine are even harder to track, almost everything's manual and nothing's really standardized. If you eat from a fast food restaurant, especially a franchise, then calories and caffeine, if provided, would be somewhat reliable, but if you make your own food, especially your own coffee and tea then it gets quite pointless, for example HK style milk tea, widely popular in SE China and among immigrants from those regions, could be stronger than espresso, but it greatly varies with the recipe and I doubt if Samsung Health has a proper entry for this.
Seems to have been a gimmick all along.