Sep 26, 2022
We know that what you eat affects your blood sugar, but what about when you eat? Or how often? And what’s happening to your blood sugar when you’re not eating? Let’s dig into how your meal schedule impacts your metabolic health.
Meal timing can make a big difference when the goal is to keep blood sugar levels stable throughout the day.
Several studies have shown that eating carbohydrate-containing meals later in the day causes a higher blood sugar response compared to consuming the same meal earlier in the day.(1,2,3) The absolute worst for your metabolism seems to be eating in the middle of the night, as shown by studies with shift workers.(4)
Being more tolerant of carbohydrates in the morning seems to be because of our internal biological clock. Many of our bodily functions developed to follow the natural light-dark or awake-sleep cycle. Metabolism is no exception.
Our gut processes food faster in the morning,(5) while the secretion of many metabolic hormones also follows the same rhythm.(6) These observations suggest that our body is just simply more efficient at processing food during the early hours.(7)
Makes sense, as energy is mainly needed during the day when we are meant to be more active, while our bodies are programmed to rest and recover during the night.
On top of when, another thing that you should be paying attention to is how often.
Our metabolism is designed to store energy from meals. That energy is then released and used between the meals. This way we don’t have to be constantly eating to keep our engines going, which is quite convenient. Fuel up, and you're good to go until the next meal.
But one of the modern world problems is that many of us ARE eating constantly, either in the form of solid snacks or sugary drinks. As it turns out, this meal pattern might actually be very bad for our health.
With constant snacking, our metabolism gets bombarded with food constantly, with no breaks in between. Our bodies were designed to alternate between feeding and fasting. The breaks between the meals also gives our metabolism a break from processing food. Our current eating habits, however, puts our metabolism under constant and unnecessary metabolic stress.
Many of us follow very inconsistent meal times throughout the week. Being inconsistent and irregular with the number of daily meals and mealtimes has been suggested to cause “metabolic jetlag”—throwing our internal biological clock out of balance. This may contribute to feeling less energetic and even sleep problems.
The mainstream health messages are often to eat 5–6 times a day. Breakfast, lunch, and dinner, accompanied by a morning and afternoon snack. Adding snacks between your main meals is often promoted for better appetite control.
Following a fixed meal schedule of 3 main meals and 3 snacks instead of having an irregular meal frequency with the number of meals alternating anywhere between 3 and 9 meals was shown to result in a more modest blood sugar response after meals just in 2 weeks! These people also experienced being less hungry before the meals and more full afterwards. (8)
But more recent findings suggest that eating even less frequently might bring some extra benefits.
Emerging research suggests that eating only 3 meals a day is more beneficial to metabolic health compared to eating more frequently, such as 6 meals a day.(9, 10) Eating less frequently, especially when timing the largest meals toward the early hours of the day may also prevent weight gain.(10)
When we think about the practical side of this approach, eating only 3 meals a day instead of 6 takes a lot less planning, making it easier to be consistent with making nutritious meal choices that support health and wellbeing.
You might have also heard about intermittent fasting, an eating pattern where all daily meals are eaten within a specific time window.
The 16:8 pattern has gained the most attention during recent years. Consume all your daily meals within an 8-hour time window, while fasting for 16-hours.
In practice, there are a couple of ways to do this, by either skipping breakfast and starting your day with lunch, or starting your day with breakfast and finishing with a very early dinner.
The metabolic magic seems to lie in the fact that a longer fasting period gives our metabolism a well deserved longer break from processing food. Intermittent fasting has been shown to lower metabolic stress and improve especially carbohydrate metabolism. And if you are trying to shed some extra pounds, intermittent fasting has also been linked to more successful weight loss.
Research suggests that following an intermittent fasting schedule where the daily eating window is timed towards the morning might have slightly more health benefits compared to a late eating schedule (11). If the 16:8 pattern sounds a bit too challenging, which it might be for some individuals due to work or family life, there is still some good news.
You don’t have to commit to an intense fasting schedule. Metabolic health can be improved even with more modest alterations. A study showed that when people delayed their breakfast and advanced their dinner for 1.5 hours each from their usual meal schedule, they were able to improve their daily fasting blood sugar and lose weight.(12)
If you decide to jump from eating more frequently to eating less frequently, avoiding low blood sugar is the key to feeling fueled and energized, even if the time between two meals grows longer. When eating only three meals a day, your meals most likely have to be slightly bigger to provide you with enough energy throughout the day—just remember to watch out for those blood sugar spikes.
The bigger the meal, the more mindful you should be about the composition of that meal. Not being mindful of your carbohydrates and how you pair them with other foods can cause unnecessary spikes and dips, making it harder to keep the brain fog and uncalled cravings at bay.
But the most important thing that should not be forgotten:
We are all individuals. What works for someone else might not be the best approach for you. And that’s where Veri comes in. With the ability to track your blood sugar throughout the day and pick up on patterns before and after your meals, you’ll gain the knowledge to design a schedule that works best for you.
1. M Takahashi et al. “Effects of Meal Timing on Postprandial Glucose Metabolism and Blood Metabolites in Healthy Adults”, 2018, Published in Nutrients. URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6266071/
2. C Morris et al. “Endogenous circadian system and circadian misalignment impact glucose tolerance via separate mechanisms in humans”, 2015, Published in Proceedings of the National Academy of Sciences. URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4418873/
3. C Bandin et al. “Meal timing affects glucose tolerance, substrate oxidation and circadian-related variables: A randomized, crossover trial”, 2014, Published in International Journal of Obesity. URL: https://www.nature.com/articles/ijo2014182
4. S Al-Naimi et al. “Postprandial metabolic profiles following meals and snacks eaten during simulated night and day shift work”, 2004, Published in Chronobiology International. URL: https://www.tandfonline.com/doi/full/10.1081/cbi-200037171
5. R Goo et al. “Circadian variation in gastric emptying of meals in humans”, 1987, Published in Gastroenterology. URL: https://pubmed.ncbi.nlm.nih.gov/3609660/
6. J Qian et al. “Differential effects of the circadian system and circadian misalignment on insulin sensitivity and insulin secretion in humans”, 2018, Published in Diabetes, Obesity and Metabolism. URL: https://dom-pubs.onlinelibrary.wiley.com/doi/abs/10.1111/dom.13391
7. C Morris et al. “The human circadian system has a dominating role in causing the morning/evening difference in early diet-induced thermogenesis”, 2015, Published in Obesity. URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4602397/
8. M Alhussain et al. “Irregular meal-pattern effects on energy expenditure, metabolism, and appetite regulation: a randomized controlled trial in healthy normal-weight women”, 2016, Published in American Journal of Clinical Nutrition. URL: https://academic.oup.com/ajcn/article/104/1/21/4633920
9. H Kahleova et al. “Meal Frequency and Timing Are Associated with Changes in Body Mass Index in Adventist Health Study”, 2017, Published in Journal of Nutrition. URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5572489/
10. A Paoli et al. “The Influence of Meal Frequency and Timing on Health in Humans: The Role of Fasting”, 2019, Published in Nutrients. URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6520689/
11. A Hutchison et al. “Time‐Restricted Feeding Improves Glucose Tolerance in Men at Risk for Type 2 Diabetes: A Randomized Crossover Trial”, 2019, Published in Obesity. URL: https://onlinelibrary.wiley.com/doi/abs/10.1002/oby.22449#.XLoJjv3rm4s
12. R Antoni et al, “A pilot feasibility study exploring the effects of a moderate time-restricted feeding intervention on energy intake, adiposity and metabolic physiology in free-living human subjects”, 2018, Published in Journal of Nutritional Science. URL: https://www.cambridge.org/core/journals/journal-of-nutritional-science/article/pilot-feasibility-study-exploring-the-effects-of-a-moderate-timerestricted-feeding-intervention-on-energy-intake-adiposity-and-metabolic-physiology-in-freeliving-human-subjects/9C604826401917A6CAD9CD10B72FEA32