In people with prediabetes or type 2 diabetes and excess weight, a personalized lower-calorie diet (based on continuous blood sugar monitoring, gut microbiome data, and more) led to no lower long-term blood sugar levels (hemoglobin A1c) and no fewer blood sugar spikes over six months than a one-size-fits-all lower-fat, lower-calorie diet.

What to do

To curb blood sugar, cut calories to lose excess weight and fill half your plate with vegetables, not refined carbs.