The BSD does not make a specific recommendation for carbs (although you’re likely to get specific recommendations in this thread). The closest they come is a recommendation to “minimize the starchy white stuff”, and “Think of them more as a side dish than a staple, and try to find alternatives.” The diet recommends, quinoa, bulgur, whole rye, whole barley, wild rice, buckwheat, oatmeal, lentils beans, and peas (and other legumes). All of these are relatively high in carbs, but also in fiber.
Because my goal is to put diabetes into remission, I started using the meal tolerances I was already aware of that manage my diabetes well. For me, that was 20 net carbs in a 2 hour period. That is NOT part of the BSD, but an added limitation I imposed, so I would be comfortable that following it would not undo the hard work I’d previously done on tight control.
Most of the meals (but not all) fall within that range. After I’d been on the BSD for a while, in an effort to move it closer to the Mediterranean ideal Mosely preaches, I tried some of the higher carb meals (made from the list of foods above – e.g. the Chickpea and Hazelnut Salad – 26 net carbs when prepared according to the recipe). I found I was able to tolerate carbs in larger quantities than I had previously been able to tolerate them.
Currently (on the BSD or not), I tend to consume between 60 and 100 net carbs (total less the fiber). Usually on the lower end.
(For reference, I’ve lost 69.5 lbs (most of it low carb-moderate protein + a calorie cap). My diabetes is under tight control, and 6 weeks of the BSD moved me from diabetic to prediabetic based on an oral glucose tolerance test, and increased my carb tolerance by about 25%).