Say it isn’t so… A study of dietary fat and blood sugar suggests I might need to bolus for fat! According to a Joslin study whose findings appeared in the April issue of Diabetes Care, dietary fat can affect blood sugar levels and insulin requirements for people with type 1 diabetes. There goes my theory that I can eat mozzarella by the pound without a budge in blood sugar. And what about my almond butter? Are all those spoonfuls of nut butter screwing with my blood sugar? Not according to my glucometer, but yes according to Joslin researchers:
In reviews of continuous glucose monitoring and food log data from adult patients with type 1 diabetes, Joslin clinicians observed that “several hours after eating high-fat meals, glucose levels went up,” says study lead author Howard Wolpert, MD, Senior Physician in the Joslin Clinic Section on Adult Diabetes and the Director of the Insulin Pump Program at Joslin. “We wanted to determine the underlying cause of these unexplained fluctuations.”
In Dr. Wolpert’s study, seven participants (adults with type 1 diabetes with an average age of 55) spent two days at Beth Israel Deaconess Medical Center eating carefully controlled meals and having their glucose and insulin levels monitored.
“All breakfasts and lunches featured identical low-fat content. The two dinners had identical carbohydrate and protein content but one was low-fat and the other high-fat. For two 18-hour periods beginning before dinner, participants had their insulin automatically regulated by a closed-loop system and their glucose and plasma insulin levels tested at frequent intervals.
Study results showed that participants required more insulin after eating the high-fat dinner than the low-fat dinner (12.6 units compared to 9 units). In contrast, the two breakfast meals required similar insulin doses. Despite the increased insulin, participants had greater hyperglycemia after the high-fat dinner with insulin levels elevated five to ten hours after the meal. The average increase in insulin was 42 percent with significant individual differences.”
So what does this mean? According to Dr. Wolpert, “These findings highlight the limitations of basing mealtime insulin dosing for type 1 diabetes solely on carbohydrate intake.”
Mike always boluses for protein as well as carbohydrate, but neither of us thinks much about fat. In fact, to my mind it’s pretty much a free food. This study makes me very curious about the ketogenic diet and type 1 diabetes. I’ve never eaten low carb enough to consider myself on a ketogenic diet, but I don’t skimp on fat, and as long as I don’t eat carbs, my blood glucose is usually in the normal range.
Apparently another study is planned “to assess whether reducing fat intake would optimize glucose control.” And, “in the coming months, Dr. Wolpert also anticipates developing new guidelines for clinicians and patients to enable them to determine whether high-fat foods are a factor in glucose control and make appropriate nutritional changes.”
Meanwhile… I guess I’ll eat more cucumbers.