"A high-calorie protein breakfast, medium-sized lunch and small dinner is a proven successful strategy for weight loss, improved satiety and reduced glucose spikes throughout the day in people with obesity and Type 2 diabetes," said lead study author Daniela Jakubowicz, MD, professor of medicine at Tel Aviv University.
"However, the benefits of high protein content at breakfast also depend on the protein source and quality," Jakubowicz said. "Whey protein powder, which is a byproduct of milk during cheese production, induced greater satiety and reduction of glucose spikes after meals compared to other protein sources, such as eggs, soy or tuna."
Jakubowicz and her colleagues investigated whether in overweight and obese people with Type 2 diabetes, whey protein for breakfast is more effective than other proteins for weight loss, satiety and reduction of glucose spikes and HbA1C (glycated hemoglobin) levels.
They randomly assigned 48 overweight and obese participants with Type 2 diabetes who were, on average, 59 years of age, to one of three diets that contained the same number of calories.
For 23 months, all participants ate a large breakfast, medium-sized lunch and small dinner, but the breakfast composition, amount and source of proteins differed among the groups.
One group ate breakfast containing mostly whey protein such as whey protein shakes, the second group ate breakfast containing other proteins including eggs, soy and tuna, and the third ate breakfast high in carbohydrates or starch.
After 12 weeks, the group on whey protein lost the most weight: 7.6 kg (16.7 pounds), compared to 6.1 kg (13.4 pounds) for those on the other proteins, and 3.1 kg (6.8 pounds) for those in the carbohydrate group.
Whey protein diet participants were more satiated and less hungry throughout the day, with lower glucose spikes after meals compared to the other two diets, and their HbA1C also decreased more than with the other two diets.