Skipping Breakfast Worsens Glycemia in Type 2 Diabetes

Miriam E Tucker

August 04, 2015

Skipping breakfast increases postmeal blood sugars after lunch and dinner in people with type 2 diabetes, new research suggests.

Results of the randomized crossover study were published online July 28, 2015 in Diabetes Care by Daniela Jakubowicz, MD, of the Diabetes Unit Wolfson Medical Center and professor of medicine at Tel Aviv University, Israel.

"In type 2 diabetes, postprandial hyperglycemia or glycemic peaks after meals are strongly associated with rapid decline in beta-cell function and with accelerated development of cardiovascular complications….Therefore, mitigating glycemic peaks is the most important target in the treatment of diabetes," Dr Jakubowicz told Medscape Medical News.

The current study, in which patients were fed breakfast vs no breakfast followed by identical lunches and dinners, shows that "by avoiding the omission of breakfast and eating most [daily] carbohydrates in the morning, when insulin is more efficient and the peaks of glucose are the smallest, will lead to significant decrease of glucose excursion [throughout] the day, [thereby] preventing the cardiovascular risk associated with high glycemic levels," she added.

The "Second-Meal Phenomenon"

Study subjects were 22 patients with type 2 diabetes whose disease was controlled with diet alone or diet plus metformin. Seven patients were also taking antihypertensive drugs. Each underwent two separate all-day meal tests with 2 to 4 weeks between test days.

On one of the days, they were given three identical standard meals — containing about 700 calories, 20% fat, 54% carbohydrate, and 26% protein — at 8:00 am, 1:30 pm, and 7:00 pm. On the other test day, they were just given the second and third meals. Blood samples were taken at all the same time points for each.

As expected, areas under the curve at 0 to 180 minutes were significantly higher following breakfast for glucose, insulin, C-peptide, and intact glucagonlike peptide-1 (GLP-1) than following no breakfast (P < .0001), as were plasma levels of those four glycemic response components before lunch (P < .0001).

However, on the no-breakfast day, plasma glucose peaks were 39.8% higher after lunch and 24.9% higher after dinner compared with the breakfast day (P < .0001). The actual values for the glucose peaks were 269 mg/dL after lunch and 294 mg/dL after dinner on days they skipped breakfast, vs 192 mg/dL and 235 mg/dL after eating an identical lunch and dinner on days they ate breakfast.

Areas under the curve at 0 to 180 minutes for glucose were 36.8% and 26.6% higher, respectively, when the subjects skipped breakfast (P < 0.0001).

Following suit, plasma insulin levels after lunch and dinner were 17% and 7.9% lower, respectively, on the no-breakfast vs breakfast-eating days (P < .0001) and peak insulin levels at 30 and 60 minutes after lunch and dinner were 24.7% and 10.8% lower, respectively (P < .0001). Values for C-peptide mirrored those of insulin after lunch and dinner.

Skipping breakfast also led to higher levels of glucagon and free fatty acids and to reduced levels of intact GLP-1 after lunch and dinner, whereas eating breakfast resulted in the reverse, Jakubowicz and colleagues report.

Authors of a previous study that showed reduced glycemia and enhanced insulin secretion after lunch with prior consumption of breakfast coined the term "second-meal phenomenon," explained by enhanced beta-cell responsiveness at the second meal after a first meal just hours earlier, when the beta-cell "memory" is stronger. This is the first study to show the phenomenon extending through dinner, the authors note.

Dr Jakubowicz told Medscape Medical News that she was a bit startled by the magnitude of the difference. "We [had] theorized that the omission of breakfast would not be healthy, but it was surprising to see such a high degree of deterioration of glucose metabolism only because the participants did not eat breakfast."

Asked what doctors should recommend to patients to eat for breakfast, she said that including protein along with carbohydrate in the breakfast is a good idea for patients with type 2 diabetes, especially if they are overweight or obese. "We know that…increasing the content of proteins [such as] tuna, salmon, cheese, chicken, or turkey will lead to decrease of hunger."

The study authors have no relevant financial relationships.

Diabetes Care. Published online July 28, 2015.Abstract


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