The diet in early-life can affect our physiology in later-life, with important consequences for metabolic health. This is nutritional programming. While we know that the period of transition between lactation and solid foods is important for nutritional programming, little is known on the role of specific nutrients, especially carbohydrates. This knowledge is essential to optimize nutrition for this critical period. We are particularly interested in carbohydrates (sugars), because this is the period when different types and forms of carbohydrates are introduced to the infant.