Meal timing and obesity: interactions with macronutrient intake and chronotype

Area of Science:

• Nutrition science
• Chronobiology
• Obesity research

Background:

• Meal timing's role in obesity is debated due to inconsistent methods.
• Previous studies often overlook chronotype and macronutrient impact on meal timing-obesity links.

Purpose of the Study:

• To investigate meal timing relative to sleep/wake patterns and its association with body mass index (BMI).
• To examine how chronotype influences the relationship between meal timing and BMI.
• To assess the impact of macronutrient timing on obesity risk.

Main Methods:

• 872 middle-to-older adults provided six 24-hour dietary recalls over one year.
• Meal timing was categorized into four windows relative to sleep: morning, night, and two midday periods.
• Body mass index (BMI), chronotype, and dietary intake data were collected.

Main Results:

• Higher energy intake during the morning window correlated with lower odds of overweight/obesity, particularly for early chronotypes.
• Increased energy intake during the night window was linked to higher odds of overweight/obesity, especially in later chronotypes.
• Carbohydrate and protein timing showed stronger associations with obesity than fat intake timing.

Conclusions:

• Dietary intake timing relative to sleep influences BMI, with variations based on individual chronotype.
• Timing of carbohydrate and protein consumption is significantly associated with obesity.
• Considering sleep-wake timing is crucial for understanding meal timing's impact on obesity and metabolic health.