Cut out any food group and your body will have a harder time digesting it if you start eating it again.
Go off bread for a while, for example, and you might end up feeling seven months pregnant when you next smash a baguette.
But if you give up dairy, the potential consequences could be more severe, with one professor claiming that you could make yourself lactose intolerant.
Many people are naturally ‘lactose maldigesters’, meaning that they struggle to digest lactose – particularly those in parts of the world where dairy plays a minimal part in the local diet.
Their bodies don’t produce much lactase – the enzyme that breaks down lactose.
As we age, our levels of the enzyme decrease, but the more dairy you eat, the more lactase your gut bacteria produce.
‘The bacteria in our colon need to be fed in order to survive,’ explains Dennis Savaiano, PhD, Meredith Professor of Nutrition Policy at Purdue University.
He tells Well + Good that whatever you feed your gut, those bacteria are going to prosper.
‘Individuals who are used to eating lactose in their diet have more lactase enzyme [than people don’t eat lactose-containing foods]—we think six to eight times more—and are more efficient at digesting it so they don’t get symptoms.’
So if you are vegan or just don’t want to consume dairy, you might want to continue supping from the plant-based cup.
If, however, you decide that you do want to start consuming animal milk, you can retrain your body to break down lactose again.