From the Guidelines
Eating late at night can be harmful, particularly if it leads to consuming additional calories beyond daily needs, disrupts sleep quality, or causes acid reflux and indigestion, and it is recommended to finish dinner at least 2-3 hours before bedtime to minimize these risks. The timing of your last meal matters less than your overall daily caloric intake and the quality of food you consume, but eating large meals close to bedtime can have negative effects on your health. According to a recent study published in Clinical Nutrition in 2024 1, late-night eating may play a role in contributing to impaired glucose metabolism, and extending the overnight fasting period can lead to a decrease in fasting glucose concentrations. Another study published in the same journal in 2024 1 found that glucose concentrations are higher at night than during the day, and that an increased risk of diabetes is associated with glucose values above the normal threshold at 4 pm but not at 8 am.
Some key points to consider when it comes to eating late at night include:
- Eating large meals close to bedtime can cause acid reflux or indigestion as lying down can allow stomach acid to flow back into the esophagus
- Late-night eating might disrupt sleep quality, particularly if you consume caffeine, alcohol, or spicy foods
- For those managing weight, nighttime eating can be problematic if it leads to consuming additional calories beyond daily needs, as metabolism naturally slows during sleep
- If you must eat late, choose lighter options like yogurt, nuts, or fruit rather than heavy, high-fat meals
- Your body's individual response matters most—some people experience no issues with late meals while others may benefit from finishing dinner at least 2-3 hours before bedtime
A study published in Current Obesity Reports in 2022 1 found that eating timing interventions, such as time-restricted eating, can improve insulin sensitivity, reduce glycemic excursions, and increase fat oxidation, and that an 8-hour time-restricted eating window can be more effective for weight loss and lowering body fat than a prolonged eating window. However, the ability to adhere to meal-timing recommendations is an important practical consideration, and shifting intake earlier in the day may prove to be challenging based on apparent preferred eating windows and/or social jetlag characteristic of adolescence.
Overall, while eating late at night is not inherently harmful, it can contribute to health issues for some people, and it is recommended to be mindful of the timing of your last meal and to prioritize overall daily caloric intake and the quality of food you consume.
From the Research
Harmful Effects of Eating Late at Night
- Eating late at night, particularly before bed, has been proposed as a factor that can negatively impact health and body composition 2.
- Consuming large mixed meals at night has been shown to have negative outcomes, including increased risk of overconsumption and weight gain 3, 4.
- However, eating small, nutrient-dense, low-energy foods before bed may not be harmful and could even be beneficial for muscle protein synthesis and cardiometabolic health 2.
Factors Influencing Late Evening Eating
- Internal signals, such as feeling hungry in the evening, can contribute to late evening eating 3.
- External and situational factors, like work schedules and a food-rich environment, can also influence late evening eating 3.
- Social factors, including interactions with family, and behavioral and emotional factors, such as personal preferences and negative feelings, can also play a role in late evening eating 3.
Impact on Cardiometabolic Health
- Late eating has been associated with cardiometabolic risk traits, including higher BMI, triglycerides, and lower insulin sensitivity 4.
- Eating at night may negatively affect postprandial lipemia, which can increase the risk of cardiovascular disease 5.
- Late eaters may also experience impaired weight loss and have higher odds of having weight-loss barriers 4.