Acute Insulin Resistance after Skipping Breakfast

A recent study suggests that overweight women who forego breakfast experience acute insulin resistance, a condition that is a risk factor for diabetes when chronic.

Elizabeth Thomas, MD, endocrinology fellow at the University of Colorado School of Medicine in Aurora, reported her team’s findings at ENDO 2013: The Endocrine Society’s 95^th Annual Meeting and Expo in San Francisco on June 16, 2013.

According to Thomas, approximately 10-20% of the population skips breakfast regularly, and this number appears to be higher among obese people. Epidemiological studies have shown associations between skipping breakfast and poor overall diet quality, higher body mass index (BMI), increased hunger, decreased satiety, and weight gain. Longitudinal studies have also found an associated increased risk of diabetes. Causal relationships have not yet been clearly established.

Previous studies have suggested that skipping breakfast for two weeks in healthy, lean women may lead to unfavorable lipid profiles and decreased insulin sensitivity. Thomas and colleagues aimed to evaluate the effects of skipping breakfast on glucose, insulin, and triglyceride levels in overweight women.

The study participants were nondiabetic women with an average age of 29.4 and an average BMI of 31.4. On two separate study dates one month apart, the women were randomized to receive either a standardized, mixed meal for breakfast or water. A standardized dinner was provided the night before, and fasting measurements were obtained the following morning before breakfast. These included glucose, insulin, free fatty acid, and triglyceride levels. All subjects received the same lunch four hours later. Repeat laboratory measurements were taken every 30 minutes after lunch for three hours.

Results showed higher peak insulin levels in subjects who did not receive breakfast, and this was sustained for over 100 minutes. Glucose levels were also significantly higher in these subjects and remained so for 180 minutes. Free fatty acids and triglycerides were higher just before lunch in the no breakfast group, as was expected, and there was no significant difference after the meal.

The authors concluded that in obese women, skipping breakfast resulted in relative insulin resistance and elevated levels of FFA. This finding is important because “it’s possible that insulin resistance over time may lead to further metabolic derangements,” said Thomas. The research team plans to extend its study to include more participants.

This study was funded by the Endocrine Fellows Foundation, the National Institutes of Health, and the Colorado Nutrition Obesity Research Center.