A variety of dietary approaches may help people with type 1 diabetes lose weight without increasing the risk of hypoglycemia or adversely affecting glycemic control, new data from pilot studies suggest.
Results from the first 3 months of the Advancing Care for Type 1 Diabetes and Obesity Network (ACT1ON) randomized trial were published online in Diabetes, Obesity & Metabolism by Daria Igudesman, PhD, postdoctoral researcher at the AdventHealth Translational Research Institute, Orlando, Fla., and colleagues .
Although overweight and obesity are commonly associated with type 2 diabetes, more than two-thirds of adults with type 1 diabetes are now also overweight or obese. That proportion has more than doubled over the past three decades, with obesity escalating from 3.4% in 1986-1988 to 36.8% in 2018, particularly among people with type 1 diabetes. And, like people with type 2 diabetes, people with type 1 diabetes have a significantly higher risk of cardiovascular disease than people without diabetes.
“It is important to control weight in people with type 1 diabetes for many of the same reasons as it is important in type 2 diabetes. Being overweight may counteract the cardiovascular benefits of intensive insulin therapy,” Igudesman told Medscape Medical News.
Still, very little research has been done on dietary approaches to weight loss in type 1 diabetes. Any such study must address the special considerations in type 1 diabetes, including the need to avoid hypoglycemia, hyperglycemia, and diabetic ketoacidosis while continuing exogenous insulin therapy. Other challenges include the need to consume carbohydrates when hypoglycemia occurs and the fear of hypoglycemia as a barrier to exercise.
In the ACT1ON pilot, three different types of diets—a hypocaloric low-carb diet, a hypocaloric Look AHEAD (moderately low-fat) diet, and a non-restricted calorie Healthy Mediterranean diet—all promoted weight loss at 3 months without adversely affecting A1c elevations risk of hypoglycaemia.
Igudesman suggests that physicians who treat patients with type 1 diabetes who are overweight or obese “should certainly take a moment to ask patients if and how they would like to talk about their weight, since it’s natural.” is a very sensitive topic for many people. If open to this discussion, then referral to a dietician or specialist in diabetes care and education [formerly known as a diabetes educator] can help develop a personalized strategy.”
3 diets All promoted weight loss, none increased A1c or hypoglycemia
The pilot study was to last for 9 months, with participants randomized to sequences of each of the three diets for 3 months each. The protocol was intended to allow re-randomization at months 3 and 6, but COVID-19 restrictions necessitated a change after the first 3 months and therefore these are the only data in the current report. Full results will be released at a later date, Igudesman said.
The participants were between 19 and 30 years old, had type 1 diabetes for at least one year and had a body mass index of 27 to 39.9 kg/m2. All were monitored with blinded continuous glucose monitoring (CGM) while also using their usual personal methods of monitoring and insulin adjustment.
After 3 months, all three diet groups lost weight: 2.4 kg (5 lb) on the low-carb diet, 1.3 kg on the Look AHEAD low-fat diet, and 2.4 kg on the Mediterranean diet. The adjusted total weight change was 2.7 kg (p<0.0001 from baseline), with no significant differences between the three groups (p=0.34). Overall, women lost significantly less weight than men (p=0.02).
A1c decreased significantly with the low-fat Look AHEAD diet (by 0.65 percentage points, P=0.027) but not with the other diets. After adjusting for multiple factors, including baseline A1c, gender, race, and ethnicity, overall A1c decreased by 0.91 percentage points (p=0.005) and was not different between diet groups (p=0.09). The percentage of time spent in the glucose range of 70-180 mg/dl was consistent with the A1c in increasing numerically but not reaching statistical significance (P=0.09), nor did it differ between diet groups (P=0.46).
The percentage of time spent with glucose levels below 70 mg/dL increased overall from baseline at 3 months (P=0.25) or in neither diet group. However, the absolute percentage of time under the range was higher in the low-carb diet group (9.1%) than with the low-fat Look AHEAD diet (3.1%) or the Mediterranean (3.3%) diet (p=0, 04). The percentage of time below a glucose level of 54 mg/dL was only 0.82% overall and did not change significantly from baseline in either group.
“Weight loss and glycemic management are not intrinsically at odds in the clinical management of [type 1 diabetes]and … a variety of dietary approaches — including those that do not require explicit calorie restriction — can be effective in meeting these equally important goals,” Igudesman and colleagues write.
Next steps will likely include another uninterrupted pilot study, followed by a full-power randomized clinical trial that includes greater standardization of aspects such as insulin dosing and activity, with the goal of predicting weight loss in people with type 1 diabetes to determine. Ultimately, the goal is to develop weight management guidelines that allow for personalized approaches.
Igudesman said, “We plan to continue this work long-term because there’s a lot more evidence that we need… in order for us to comply with these guidelines.” This is really a long-term endeavor.”
The research was funded by the National Institutes of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health. Igudesman was supported by the NIH Global Cardiometabolic Disease Training Grant awarded to the Department of Nutrition at the University of North Carolina at Chapel Hill.
diabetes obesity metab. Published online October 31, 2022. Abstract
Miriam E. Tucker is a freelance journalist based in the Washington, DC area. She is a regular contributor to Medscape, and other work appears in The Washington Post, NPR’s Shots blog, and Diabetes Forecast magazine. She is on Twitter: @MiriamETucker.
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