“Metabolic diseases are on the rise globally, with type 2 diabetes and obesity as leading concerns in human health,” Dr. Goff and team said. “Thus, there is impetus to develop dietary strategies for the risk reduction and management of obesity and diabetes to empower consumers to improve their personal health.”
In this randomized, controlled, double-blinded study, the team examined the effects of increasing protein concentration and increasing the proportion of whey protein in milk consumed with a high-carbohydrate breakfast cereal on blood glucose, feelings of satiety, and food consumption later in the day. Digestion of the whey and casein proteins naturally present in milk releases gastric hormones that slow digestion, increasing feelings of fullness. Digestion of whey proteins achieves this effect more quickly, whereas casein proteins provide a longer lasting effect.
Although the team only found a modest difference in food consumption at the lunch meal when increasing whey protein at breakfast, they did find that milk consumed with a high-carbohydrate breakfast reduced blood glucose even after lunch, and high-protein milk had a greater effect. Milk with an increased proportion of whey protein had a modest effect on pre-lunch blood glucose, achieving a greater decrease than that provided by regular milk.
According to Dr. Goff and colleagues, “This study confirms the importance of milk at breakfast time to aid in the slower digestion of carbohydrate and to help maintain lower blood sugar levels. Nutritionists have always stressed the importance of a healthy breakfast, and this study should encourage consumers to include milk.”
The study is available online at https://doi.org/10.3168/jds.2018-14419.