Does eating after 8 pm contribute to weight gain?

Does Eating After 8 PM Contribute to Weight Gain?

The evidence regarding eating after 8 PM and weight gain is mixed, with no conclusive evidence that the specific time of 8 PM is a critical cutoff for weight gain in adults or children. 1

Current Evidence on Meal Timing and Weight

• Studies examining the relationship between evening meal timing and weight status show inconsistent results, with some suggesting associations between later eating and weight gain while others show no significant effect 1

• In a UK study of 1,620 children aged 4-18 years, researchers found that consuming the evening meal after 8 PM did not increase the risk of overweight or obesity compared to eating between 2 PM and 7:59 PM 1

• A 7-year prospective study of 8-12-year-old girls found that eating later in the day (between 5 PM and 6 AM) was associated with a small but significant increase in BMI z-score 1

• In adults, a cross-sectional study showed that individuals who consumed ≥33% of their daily energy intake in the evening were twice as likely to have overweight or obesity, though this association was not significant when controlling for accurate energy reporting 1

Proportion of Calories vs. Specific Timing

• Research suggests that the proportion of total daily calories consumed in the evening may be more important than the specific clock time of eating 1:

  • Individuals who consume a greater percentage of their daily calories in the latter part of the day may have higher body weight 1

  • In children ages 6-11, a greater proportion of daily energy consumed later in the day was associated with higher body weight 1

• No significant differences were found between the proportion of energy consumed between 8:00 PM and midnight and weight status in several studies 1

Potential Mechanisms

• Late-night eating may disrupt circadian rhythms that regulate metabolism, potentially leading to metabolic inefficiency 2, 3

• Sleep-restricted adults with late bedtimes may consume more total daily calories, with a higher percentage of calories from fat during late-night hours (22:00-03:59) 4

• Evening intake of protein, carbohydrates, and fat after 8:00 PM has been associated with higher BMI and greater total caloric intake in some studies 5

Important Considerations and Caveats

• The mere consumption of an evening meal after 8:00 PM may not result in the same level of metabolic disruption as more substantial shifts in eating patterns (e.g., shift work schedules) 1

• Total caloric intake and dietary quality remain the primary determinants of weight management, regardless of timing 1

• Time-restricted eating interventions (limiting eating to an 8-10 hour window) have shown mixed results for weight loss:

  • Some studies suggest benefits for weight management and metabolic health 1

  • A randomized clinical trial found that time-restricted eating (12:00 PM-8:00 PM eating window) was not more effective for weight loss than eating throughout the day 6

• Individual factors such as sleep patterns, chronotype, and daily schedule may influence the impact of meal timing on weight 4, 3

• Most dietary guidelines continue to focus on caloric intake, diet composition, and portion size rather than the specific timing of meals 1