Advantages of Less-Frequent, Higher Calorie Meals

Researchers compare three-meal diet to six meals/snacks: can eating fewer meals per day lead to less hunger and better control of diabetes?      

Diet and lifestyle changes are essential counseling points in patients who have been diagnosed with diabetes. Many diets have been proposed to help control diabetes. Diets are often hard to stick to, and patients frequently require increasing intervention, with many patients eventually requiring insulin. Insulin therapy frequently results in weight gain, which may increase insulin resistance, resulting in a need for even more insulin; thus, preventing weight gain is very important. One diet that has been suggested is a six-meal diet that consists of three meals with three snacks between those meals. This study argues that the evidence for such suggestions is inadequate. Previous studies have supported the idea of decreasing meal frequency to two or three meals daily, with meals earlier in the day.  

This study wished to evaluate the impact of a three-meal diet that had high energy and carbohydrate intake at breakfast. This three-meal diet was compared to a six-meal diet that had calories and carbohydrates distributed evenly throughout the day. These diets lasted for 12 weeks, with weight, glycemic control, and appetite being assessed. The 44 participants were ≥25 years old, had type 2 diabetes for ≥five years, received insulin treatment for ≥one year with a total daily insulin dose of >25 units per day for ≥three months, had an HbA1c of ≥6.5%, and a BMI of ≤45. The study was a randomized, controlled, parallel. Patients were assigned to either the three-meal or the six-meal arm by a coin flip. Participants’ adherence to the diet was assessed every two weeks by a nutritionist and they met bi-weekly with a physician to titrate insulin. The primary endpoint was the change in the total daily dose of insulin, with secondary endpoints being body weight, glycemic control, and craving scores. Both diets were calculated using the Harris-Benedict equation and subtracting 500 kcal from this. Both had the same macronutrient composition, consisting of 35% fat, 25% protein, and 40% carbohydrate. The difference was the meal timings, frequency, and calories and carbs distribution throughout the day. The three-meal diet had a breakfast of 700 kcal, a 600 kcal lunch, and a 200 kcal dinner. The six-meal diet had a 300 kcal breakfast, 375 kcal lunch and dinner, and three snacks each consisting of 150 kcal. All participants were asked to eat breakfast before 0930, lunch from 1200-1500, and dinner from 1800-2000. The six-meal diet also had snacks at 1100, 1700, and 2200.  

At the end of 12 weeks, the three-meal diet showed greater weight loss of 5.4 ± 0.9 kg (P < 0.0001) compared to nonsignificant weight loss in the six-meal diet. The BMI of those in the three-meal diet was significantly lowered versus those in the six-meal diet (P < 0.0001).The three-meal diet saw a 1.2% decrease in HbA1c (from 8.2% to 7%) (P < 0.0001), with no significant decrease in the six-meal arm (P = 0.5), resulting in a significant difference between them (P = 0.04). Fasting blood glucose was significantly decreased in both groups, with the three-meal arm having a greater reduction (P = 0.005). There was a significant increase in time spent at healthy blood glucose levels only in the three-meal arm, increasing from 14 hours 14 minutes to 20 hours 10 minutes (P < 0.01). Similarly, time in hyperglycemia decreased significantly only in the three-meal arm, from 8 hours 59 minutes to 3 hours 3 minutes (P < 0.01). Nighttime hyperglycemia was also significantly reduced in only the three-meal arm. Time spent in hypoglycemia was low at baseline and did not change significantly in either arm. Due to this decrease in glycemia, the total daily insulin dose was decreased by 26 ± seven units (P < 0.05) in the three-meal arm. In the six-meal arm, there was a nonsignificant increase in the daily insulin dose by four ± 3.7 units. Overall, the three-meal arm was treated with significantly lower insulin doses of 34 ± seven units, versus 76 ± 15 units in the six-meal arm (P = 0.001). At the end of the study, there was a significant decrease in cravings in only the three-meal arm (P < 0.01). 

Despite the significant decreases in glycemia, there were no changes in the number of hypoglycemic events, meaning the three-meal arm was a safe and effective way to help patients control their type 2 diabetes. There was no correlation seen between body weight and insulin dose, so the decrease in insulin was likely independent of weight loss. The simple change of eating fewer meals resulted in a significant reduction in HbA1c, body weight, cravings for food, time spent in hyperglycemia, and insulin doses when compared to a diet consisting of six meals per day.  

Practice Pearls: 

• HbA1c was reduced by 1.2% in the three-meal diet arm.   
• While popular, the six-meal diet failed to show any advantages when compared to a three-meal diet.  

• The three-meal diet resulted in decreased cravings and hunger when compared to a diet that consisted of six smaller, more evenly spaced meals.  
• The authors used a simple breakdown of 700 kcal for breakfast, 600 kcal for lunch, and 200 kcal for dinner. 

Jakubowicz, Daniela, et al. “Reduction in Glycated Hemoglobin and Daily Insulin Dose Alongside Circadian Clock Upregulation in Patients With Type 2 Diabetes Consuming a Three-Meal Diet: A Randomized Clinical Trial.” Diabetes Care, American Diabetes Association, 1 Dec. 2019, care.diabetesjournals.org/content/42/12/2171. 

George McConnell, PharmD. Candidate, LECOM School of Pharmacy 

See more about the role of diet and nutrition in diabetes.