HOUSTON — Considering macronutrient composition and meal timing when dieting may prevent weight regain in obese patients by curbing diet-induced compensatory changes in hunger, cravings and ghrelin suppression, according to Daniela Jakubowicz, MD.
Jakubowicz, of E. Wolfson Medical Center at Tel-Aviv University in Israel, and colleagues conducted two studies examining whether adding a high-carbohydrate and high-protein breakfast would counteract these changes that may result from caloric restriction.
One study was composed of 193 obese men and women aged 47 years with sedentary lifestyles and without diabetes. They were randomly assigned to a low-carbohydrate breakfast or an isocaloric diet with a high-carbohydrate and high-protein breakfast.
Weight, height, fasting blood glucose, insulin, ghrelin, lipids and craving scores were measured every 4 weeks. Researchers also performed breakfast meal challenges to assess hunger, satiety, insulin and ghrelin responses at baseline, after a 16-week diet intervention period and after a 32-week follow-up period.
“At week 16, both diets worked the same. Weight loss was similar between the low-carbohydrate diet and enriched-breakfast diet groups,” Jakubowicz said.
The low-carbohydrate and enriched-diet groups lost 15.1 kg and 13.5 kg, respectively. However, the low-carbohydrate study arm regained 11.6 kg from weeks 16 to 32, whereas the enriched-diet arm lost an additional 6.9 kg, Jakubowicz reported. Further data indicated that ghrelin levels decreased by 45.2% after breakfast in the enriched-diet group vs. 29.5% in the low-carbohydrate group. Researchers also noted significant improvements in satiety, and reductions in hunger and craving scores in the enriched-diet group compared with the low-carbohydrate group.
Effects of meal-timing
In a similar study also led by Jakubowicz, researchers evaluated the influence of meal timing (increased caloric intake in the morning vs. evening) on weight loss, ghrelin suppression, lipid levels and appetite scores.
Jakubowicz and colleagues randomly assigned 73 obese women, aged 46 years to one of two isocaloric (1,400 calories) diets during a 12-week period. Dietary composition was the same for both groups, but meals were administered at different times.
The high-calorie breakfast diet included a 700-calorie breakfast (50% carbohydrates, 30% protein and 20% fat), a 500-calorie lunch (20% carbohydrates, 45% protein and 25% fat), and a 200-calorie dinner (13% carbohydrates, 40% protein and 47% fat).
The high-calorie dinner diet included a 200-calorie dinner (13% carbohydrates, 40% protein and 47% fat), a 500-calorie lunch (20% carbohydrates, 45% protein, 25% fat), and a 700-calorie dinner (50% carbohydrates, 30% protein and 20% fat).
After 12 weeks, the high-calorie breakfast group lost 8.7 kg compared with 3.48 kg in the high-calorie dinner diet group.
Moreover, the high-calorie breakfast group experienced a 61% greater weight loss than the high-calorie dinner group (P<.05), a 35% greater reduction in waist circumference (P<.06) and a 17% greater reduction in body fat. Ghrelin levels decreased after breakfast by 46.2% in the high-calorie breakfast group and 18.5% after dinner in the high-calorie dinner group (P>.005).
Results also revealed improved satiety and significantly decreased hunger and craving scores in the high-calorie breakfast group compared with the high-calorie dinner group (P>.005).
Average serum triglycerides decreased by 44% in the high-calorie breakfast group. However, there was a 6.3% increase in the high-calorie dinner group (P>.005). No significant differences were noted in total cholesterol, HDL and LDL between groups.
The researchers concluded that isocaloric diets with different meal timing comparatively influenced weight-loss rate, ghrelin, appetite and lipid levels.
In conclusion, Jakubowicz said that a diet including a high-calorie breakfast with reduced caloric intake at dinner may result in enhanced weight loss and increased ghrelin suppression.
“It might be useful for the management of obesity,” Jakubowicz said. – by Samantha Costa
For more information:
Jakubowicz D. Abstract: MON-85.
Jakubowicz D. Abstract: SUN-LB3. Both presented at: the Endocrine Society’s 94th Annual Meeting & Expo; June 23-26, 2012; Houston.
Disclosure: The researchers report no relevant financial disclosures.