Researchers assigned 32 healthy adults to eat a breakfast containing two servings of a high-carbohydrate cereal, with either 1 cup of commercial milk that contained 12.4 grams of protein, or 1 cup of milk mixed with a whole-milk protein concentrate or a whey protein powder that boosted protein intake to 28 grams. The participants then had their blood sugar levels measured.
After two to three hours, the participants ate a high-carb lunch and had their blood sugar checked again. Later, everyone’s appetite was assessed with a questionnaire. The researchers found that people who consumed extra protein at breakfast had lower blood sugar levels and reduced appetite later in the day compared with those consuming less protein.
Protein takes longer to digest than carbohydrates do, which explains why it can suppress appetite, but the study also suggests that the more protein you consume, the longer the effect may last. This could be helpful for people who fight afternoon cravings or who need help to lose and manage their weight. Although this study used milk and whey protein powder, the researchers added that it’s conceivable that any protein source would work as well.
Source: Harvard Medical School