When healthy young adults eat a low-carbohydrate diet high in protein for seven days, their blood insulin levels rise more after a meal than when they eat a low-carbohydrate diet high in fat.

When healthy young adults eat a low-carbohydrate diet that is higher in protein instead of higher in fat, their blood glucose levels after eating are lower two hours later.

In adults with type 2 diabetes, eating a diet with less carbohydrate and more protein for six weeks leads to lower blood glucose levels after meals and throughout the day, even without losing weight.

For overweight people with type 2 diabetes, eating fewer carbs and more protein for 6 weeks makes it more likely their blood sugar will dip low without them feeling it—82% had low readings compared to 70% on a normal diet—but no one passed out or had a medical emergency.

When you eat a high-protein diet with no carbs but lots of fat, you feel less hungry and more full than when you eat the same amount of protein but with some carbs.

If you're overweight, eating a lot more protein — especially from whey — for a month won't help your body use insulin better unless you're also losing weight.