What’s the best diet if you have prediabetes or type 2 diabetes?

Researchers assigned 33 people with prediabetes or type 2 diabetes to eat a “Well-Formulated Keto Diet” or a “Mediterranean-Plus Diet” for 12 weeks each, in random order.

Both diets were rich in non-starchy vegetables and low in added sugars and refined grains. The Mediterranean diet included beans, fruits, and whole intact grains. The Keto diet had none, except for small amounts of some berries.

Hemoglobin A1c (a long-term measure of blood sugar) fell by about 8 percent on both diets. LDL (“bad”) cholesterol was higher on the Keto diet than on the Mediterranean diet, though triglycerides were lower. After 36 weeks, both groups had lost about 15 pounds. Each cut about 250 to 300 calories a day.