By Kathleen Doheny
When women skipped the morning meal, they experienced insulin resistance, a condition in which a person requires more insulin to bring their blood sugar into a normal range, explained lead researcher Dr. Elizabeth Thomas, an instructor of medicine at the University of Colorado.
This insulin resistance was short-term in the study, but when the condition is chronic, it is a risk factor for diabetes, Thomas said. She is due to present her findings this weekend at the Endocrine Society's annual meeting in San Francisco.
Diabetes has been diagnosed in more than 18 million Americans, according to the American Diabetes Association. Most have type 2 diabetes, in which the body does not make enough insulin or does not use it effectively.
Excess weight is a risk factor for diabetes.
The new study included only nine women. Their average age was 29, and all were overweight or obese.
Thomas measured their levels of insulin and blood sugar on two different days after the women ate lunch. On one day, they had eaten breakfast; on the other day, they had skipped it.
Glucose levels normally rise after eating a meal, and that in turn triggers insulin production, which helps the cells take in the glucose and convert it to energy.
However, the women's insulin and glucose levels after lunch were much higher on the day they skipped breakfast than on the day they ate it.
On the day they did not eat breakfast, Thomas explained, "they required a higher level of insulin to handle the same meal."
"There was a 28 percent increase in the insulin response and a 12 percent increase in the glucose response after skipping breakfast," she said. That's a mild rise in glucose and a moderate rise in insulin, she noted.
Because this study was presented at a medical meeting, the data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.
"Their study doesn't prove causation," said Dr. Joel Zonszein, a professor of clinical medicine at the Albert Einstein College of Medicine and director of the Clinical Diabetes Center at Montefiore Medical Center, in New York City.
The study found only a link or association between breakfast skipping and higher insulin levels. More research is needed for confirmation, another expert said.
"This is a small, but very interesting, study," said Dr. Ping Wang, director of the University of California, Irvine, Health Diabetes Center. "The findings will have to be verified with larger studies."
Whether the effect is short-term or long-term is not known, Wang said.
Zonszein recommends against either skipping meals or eating very frequent meals, the so-called nibbling diet. "Studies done in Europe have shown that a large meal in the middle of the day is better than a large meal at dinner," he said.
However, he acknowledged that pattern is more of a habit in Europe than in the United States. Even so, he advises his patients to eat a good breakfast, a good lunch and a lighter dinner.