I love yogurt, and understand that the bacteria in yogurt break down the lactose from milk into glucose and galactose, and then break down those two sugars into lactic acid. In theory, there should be no remaining sugar in plain yogurt, so long as the bacteria have been given a chance to do their work. I also understand that the carbs listed on the nutrition label of yogurt containers are calculated using the “difference method”, and are based on the macro-nutrient makeup of the input milk ingredients before the bacteria have their little nibble on the sugars - this may be different in some countries, but nonetheless there are plenty of carbs listed on the label which may in theory not be there at all after fermentation.
However, even if all the sugars are fermented, I am having trouble finding info on what the body does with the resulting dietary lactic acid in yogurt. Is this a source of energy, and is it converted into glucose by the liver or in some other process, perhaps in a similar way lactate is converted into glucose by the liver during intense exercise?
This of course only applies to plain yogurt, and not the many products with sugars added. I also understand that plain Greek yogurt may have less unfermented sugar, as Greek yogurt is drained to achieve that lovely thickness and often the sugars depart with this liquid.
So what is the verdict on plain yogurt and lactic acid - is it keto-friendly?