 There's substantial evidence, not only from observational studies, but also from intervention trials that dairy products can help reduce weight or reduce weight gain with time. The most successful intervention studies have been those that are looking at weight loss diets and putting dairy as part of a weight loss diet seems to be able to enhance the effects of weight loss. So in Framingham study, we looked at over 3,000 individuals and followed them for over 12 years and we were able to see that overall dairy products did reduce weight gain in that cohort by over 50% over that time period. We also saw that it also reduced the rate of gain in waste circumference by about 15% over that same time period. Yogurt is a really, you can think of it as a condensed form of dairy where we're really enhancing the levels of protein, calcium and magnesium and potassium relative to other dairy products. So it's a very nutritionally dense food. So conceptually we have a good idea of what nutrient density means and what nutrient dense foods are. Operationally it can be very difficult though because there's many different ways of operationalizing nutrient density trying to define, you know, how you characterize a food as nutrient dense and the debate over energy and obesity that we really want to focus on foods that are nutrient dense, that they have a high levels of nutrients of need relative to the caloric content of the product. So it's not only nutrient dense food, it's also a nutrient dense food that provides nutrients that we really need that are short in our diet.