Meal timing is becoming a hot topic amongst the health conscious, but does it really matter? Does it affect our weight, our blood sugar levels and metabolism?
Firstly, I must acknowledge the fact that we are all biochemically unique, and therefore what works for your friend or partner may not work for you.
Over the last few years, many studies have been conducted on a type of intermittent fasting called time restricted eating (see article about intermittent fasting here). The overall consensus of the research is that restricting the time you are eating during the day (to just 10 hours for example] can have an impact on factors such as weight and cardiovascular disease risk, independent of what you eat.
This body of research has highlighted that timing of food intake is important, so let us now delve deeper into the impact of the evening meal. Timing of the evening meal can vary depending on children, work commitments, shift work and commuting, but does the time of it impact how our bodies processed the food?
What does the research say?
A very recent small-scale study of 20 participants found that those who consumed a late dinner (10pm) compared with a routine dinner (6pm) had higher blood sugar levels (18% higher) and burned less fat (10% less) in repose to the same meal. This essentially means that the body is less effective at processing and metabolising the same meal if it is consumed later in the evening.
These differences in metabolism are also seen when comparing the same meal consumed in the morning to the evening. Results from this study showed that the body was more effective at metabolising the same meal consumed at 9am compared to at 5pm.
So, what does this mean for us? Researchers of the evening meal time study commented that if the 10pm dinner time was to occur regularly, this may contribute to increased risks of weight gain and metabolic disorders such as type 2 diabetes, as these conditions can be associated with increased blood sugar levels.
This research highlights the importance of the effect of daytime and night-time (light and dark cycles) on our bodies ability to process our food. Where possible, we should favour consuming our evening meal earlier rather than later into the evening, where our schedules permit.
You may have heard of the phrase: Eat breakfast like a king, lunch like a prince and dinner like a pauper. This is reflecting consuming a larger meal in the morning, like the studies suggests, and reducing the size of meals as the day goes on.
I must highlight that the studies mentioned above were conducted with healthy individuals, free of disease, so the findings may have been different if looking into different subsets of the population. The bedtime of participants may also play a role as the study looked at a 10pm dinner time with an 11pm bedtime, therefore a later bedtime may have changed the outcome. The sample sizes of the studies were also small, thus more research on a larger scale would be required to gain more firm understandings. Other factors such as stress levels and duration of sleep can also impact our blood sugar levels and stress hormone levels, so these factors will also play a role in the overall effect on our metabolism.
We can see that meal timing does influence our bodies blood sugar levels and fat burning ability, so it is something to consider when analysing our current diet and lifestyles. Where possible, earlier evening meals may have benefit over late evening meals, however the odd late evening meal, such as when out for a celebration or on holiday, is unlikely to have lasting effects on our body. Overall, more research is needed on a larger sample size in this area.
*** This blog post is not intended or implied to be a substitute for seeking professional medical advice, diagnosis, or treatment. Information provided here is general and is not intended to treat, diagnose, prevent, or cure any diseases or conditions. Please contact your GP or private health consultant if you have any personal health concerns or consult a registered nutritional therapist for personalised dietary and lifestyle advice and guidance.
Chenjuan Gu, Nga Brereton, Amy Schweitzer, Matthew Cotter, Daisy Duan, Elisabet Børsheim, Robert R Wolfe, Luu V Pham, Vsevolod Y Polotsky, Jonathan C Jun, Metabolic Effects of Late Dinner in Healthy Volunteers – A Randomized Crossover Clinical Trial, The Journal of Clinical Endocrinology & Metabolism, , dgaa354, https://doi.org/10.1210/clinem/dgaa354
Takahashi, M., Ozaki, M., Kang, M.I., Sasaki, H., Fukazawa, M., Iwakami, T., Lim, P.J., Kim, H.K., Aoyama, S. and Shibata, S., 2018. Effects of meal timing on postprandial glucose metabolism and blood metabolites in healthy adults. Nutrients, 10(11), p.1763.