What is the fine-grained topic of the following text: A recent review of 10 commercial weight loss programs by researchers at Johns Hopkins published in the June issue of Obesity Reviews Journal ‡, found that only those individuals with type 2 diabetes following the Jenny Craig program reduced hemoglobin A1c — a three-month average of blood sugar concentrations — more than weight loss counseling at 12 months. Only return the topic.
Effectiveness of Jenny Craig program on Type 2 diabetes patients' blood sugar levels.