Eating Two Larger Meals a Day (Breakfast and Lunch) Is More Effective Than Six Smaller Meals in a Reduced-Energy Regimen for Patients With Type 2 Diabetes: A Randomised Crossover Study

Study Questions:

Are two meals per day (breakfast and lunch) better for body weight, hepatic fat content, insulin resistance, and beta cell function compared to six meals per day?

Methods:

This was a randomized, open, crossover study, which included 54 patients (ages 30-70 years) with type 2 diabetes. All were treated with oral hypoglycemic agents, had body mass index (BMI) between 27-50 kg/m2, and glycated hemoglobin 6-11.8% (42-105 mmol/mol). Subjects were randomized to 12 weeks of either six meals per day (breakfast, lunch, dinner, and three snacks) or two meals per day (breakfast and lunch). Composition of the diets followed Association for the Study of Diabetes guidelines, with the same caloric restriction of 500 kcal/day, based on each subject’s resting energy expenditure. The diets derived 50-55% of total energy from carbohydrates, 20-25% from protein, and <30% from fat, with 30-40 g/day of fiber. All meals were provided to half of each group, while the other half prepared their own meals. The primary outcomes included BMI, hepatic fat content (measured with proton magnetic resonance spectroscopy), insulin resistance, and beta cell function.

Results:

The intention-to-treat analysis included all participants (n = 54). Body weight decreased in both regimens (p < 0.001), but was more pronounced in the two meals/day group (−2.3 kg; 95% confidence interval [CI] −2.7 to −2.0 kg for six-meals/day group vs. −3.7 kg; 95% CI, −4.1 to −3.4 kg for two meals/day group; p < 0.001). Hepatic fat content decreased in response to both regimens (p < 0.001), more for two meals/day group (−0.03%; 95% CI, −0.033% to −0.027% for six-meals/day group vs. −0.04%; 95% CI, −0.041% to −0.035% for two meals/day group; p = 0.009). Fasting plasma glucose and C-peptide levels decreased in both regimens (p < 0.001), more for two meals/day group (p = 0.004 and p = 0.04, respectively). Fasting plasma glucagon decreased with the two meals/day regimen (p < 0.001), whereas it increased (p = 0.04) for six-meals/day regimen (p < 0.001). Oral glucose insulin sensitivity increased in both regimens (p < 0.01), more for two meals/day group (p = 0.01). No adverse events were observed for either regimen.

Conclusions:

The investigators concluded that eating only breakfast and lunch reduced body weight, hepatic fat content, fasting plasma glucose, C-peptide, and glucagon, and increased oral glucose insulin sensitivity more than the same caloric restriction split into six meals. These results suggest that, for type 2 diabetic patients on a hypoenergetic diet, eating larger breakfasts and lunches may be more beneficial than six smaller meals during the day.

Perspective:

These data suggest that the number of meals per day has clinical impact on diabetic control. Further research in a larger cohort, including research on the mechanisms for such a difference, is warranted.

Keywords: Meals, Glycated Hemoglobin A, Eating, Diabetes Mellitus, Type 2, Breakfast, Lunch


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