Why intermittent fasting may offer a promising alternative to calorie-restricted diets
The rates of type 2 diabetes are on the rise, affecting one in ten adults in the United States. People with diabetes are often prescribed calorie-controlled and carbohydrate-restricted diets by their physicians to help manage diabetes and promote weight loss. Unfortunately, traditional restrictive diets that cut out major food groups or require calorie counting can be unsustainable long-term. Time-restricted eating, also known as intermittent fasting, may offer a safe and effective dietary solution for weight management and better blood sugar control for individuals diagnosed with type 2 diabetes.
Intermittent fasting (IF) involves various meal timing schedules that switch between voluntary fasting and eating over a period of time. A popular IF eating schedule involves eating during an eight-hour window followed by fasting for 16 hours. Longer fasting periods, greater than 24 hours, may not be beneficial and may even be dangerous. While traditional diets emphasize what and how much to eat, intermittent fasting focuses on when to eat.
Although studies on intermittent fasting are relatively small and limited, there are reported benefits associated with time-restricted eating. Generally, IF appears to have a positive impact on body weight, blood sugar balance and lipid levels while offering anti-inflammatory effects similar to those achieved with calorie restriction.
A new University of Illinois Chicago study published in JAMA Network Open found that time-restricted eating can help those with type 2 diabetes lose weight and control blood glucose levels. Study participants who ate within an eight-hour window, between noon and 8 PM, lost more weight during a six-month period than those who were assigned to follow a diet with a 25 percent reduction in calories. Those in the intermittent fasting group had an easier time adhering to the plan compared to those on the calorie-restrictive diet.
Another small-scale study published last year in the Endocrine Society’s Journal of Clinical Endocrinology & Metabolism found that participants with diabetes were able to reduce their diabetes medication after intermittent fasting. Some participants even experienced diabetes remission for at least one year. Additional studies have shown that intermittent fasting can improve insulin sensitivity and blood sugar control, helping to prevent or delay type 2 diabetes in those with prediabetes.
Some of the appeal of intermittent fasting is that it provides structure for when to eat without limiting food options. Consistency may be more easily achieved on an IF plan compared to a low carbohydrate diet, for example, which may feel overly restrictive and daunting after just a few weeks. However, it is important to eat healthful and balanced meals on an IF eating plan to get adequate nutrition.
Intermittent fasting is not for everyone and it is important to speak with your health care provider before starting a time-restricted eating plan. Those who should avoid intermittent fasting include children and teens, people with type 1 diabetes, people who are pregnant or breastfeeding and those with a history of eating disorders. A registered dietitian can help you customize an eating plan for better blood sugar control that includes intermittent fasting.
LeeAnn Weintraub, MPH, RD is a registered dietitian, providing nutrition counseling and consulting to individuals, families and organizations. She can be reached by email at RD@halfacup.com.