Omitting Breakfast Impairs Insulin Sensitivity & Leads to Weight Gain

Deleterious effects of omitting breakfast on insulin sensitivity and fasting lipid profiles in healthy lean women. This aim of this study by Nottingham researchers was to ascertain whether eating breakfast or omitting breakfast affects energy intake, energy expenditure, and circulating insulin, glucose, and lipid concentrations in healthy women.

In a randomized crossover trial, 10 women with a mean BMI of 23.2 underwent two 14-day eating breakfast or omitting breakfast interventions separated by a 2-week interval. In the eating breakfast period, subjects consumed breakfast cereal with 2%-fat milk before 0800 and a chocolate-covered cookie between 1030 and 1100. In the omitting breakfast period, subjects consumed the cookie between 1030 and 1100 and the cereal and milk between 1200 and 1330. Subjects then consumed 4 additional meals with content similar to usual at predetermined times later in the day and recorded food intake on 3 days during each period. Fasting and posttest meal glucose, lipid, and insulin concentrations and resting energy expenditure were measured before and after each period.

They found: “Reported energy intake was significantly lower in the eating breakfast period (P = 0.001), and resting energy expenditure did not differ significantly between the 2 periods. Omitting breakfast was associated with significantly higher fasting total and LDL cholesterol than was eating breakfast (3.14 and 3.43 mmol/L and 1.55 and 1.82 mmol/L, respectively; P = 0.001). The area under the curve of insulin response to the test meal was significantly lower after eating breakfast than after omitting breakfast (P < 0.01).”

The researchers concluded: “Omitting breakfast impairs fasting lipids and postprandial insulin sensitivity and could lead to weight gain if the observed higher energy intake was sustained.” Further: “Breakfast consumption is recommended, despite inconclusive evidence of health benefits.”

American Journal of Clinical Nutrition, Vol. 81, No. 2, 388-396, February 2005.