Milk and dairy products contain significant amounts of nutrients that contribute to optimal health – nutrients like calcium, vitamin D, and high-quality protein. Fermented milk products or fermented dairy products are foods that have been fermented with certain bacteria. Yogurt is a fermented dairy product containing millions of beneficial bacteria. In this study, we will look at the effect of milk (a non-fermented dairy product) and yogurt (a fermented dairy product) supplementation on bone health and the amount of fat and muscle mass in Canadian young adults over a 24-month period. While dairy products contain significant amounts of nutrients, we do not know the impact of long-term supplementation of fermented (i.e., yogurt) or non-fermented (i.e., milk) dairy food consumption on bone health and the amount of fat and muscle mass in young adults. To fill this knowledge gap, we will recruit participants with low calcium intake and assign them to three different groups: 1) milk (intervention) group; 2) yogurt (intervention) group; and 3) control group. We will ask the participants in the milk group to drink 1.5 servings (375 mL) of milk per day for 24 months. Participants in the yogurt group will consume 2 servings (350 g) of yogurt per day for 24 months. Those in the control group will continue their usual diets. Using a randomized controlled trial design, we will measure bone health parameters, hormonal indices related to bone metabolism, body composition (e.g., muscle mass, fat mass), and the number and composition of bacteria living in the gastrointestinal (GI) tract. The data will provide valuable information for developing targeted health initiatives and marketing strategies regarding the benefits of fermented and non-fermented dairy product consumption.