When people with type 2 diabetes and obesity follow a low-carb diet for 12 weeks, it lowers a specific protein in their blood that's linked to better health.

People with obesity, prediabetes, or type 2 diabetes tend to have higher levels of a hormone called FGF-21 in their blood compared to healthy-weight people, and the more severe the metabolic issue, the higher the level seems to go.

Blocking a hormone called FGF21 in fasting mice doesn’t really change their blood sugar, energy levels, or liver fuel stores — meaning this hormone might not be essential for how their bodies adapt to not eating for a short time.

Some people who are obese but still respond well to insulin have higher levels of a hormone called FGF21 in their blood compared to obese people whose bodies don’t respond as well to insulin—even though they weigh about the same.

When mice don't have enough of a protein called FGF21 during fasting, their livers store more fat because they burn less fat and take in more from the blood — but this doesn't affect how the body overall uses energy.

A special low-carb diet for 12 weeks helps overweight people with diabetes lose fat from their liver, making their liver healthier.