Janny discovers how much sugar we unknowingly consume and what that does to our brain. Brace yourself, because the results are shocking. Especially the amount of sugar that young people consume these days. To make them aware of this, Janny gives the teenagers from year 4 HAVO at the Alkwin College in Uithoorn a lesson in reading labels. And she shows how to make a delicious mayonnaise, without sugar.

• Janny van der Heijden