What, how much and when to eat
It's well documented, that what and how much we eat and drink affects our body composition and health. Thanks to recent nutritional research, it is more evident that when we eat is also an important factor for consideration. The no carbs after 8pm; is that really a thing? We’ve enlisted the help of our resident nutritionist Gareth Nicholas, to share the latest scientific opinion on how the timing of food consumption affects your weight and well-being.
Tick tock biological clocks
Eat, Train, Sleep, Repeat! Human behaviours and health functions are coordinated by our circadian rhythm. The NIH state that circadian rhythms are physical, mental and behavioural changes that follow a 24-hour cycle. This is most noticeable in the sleep cycle. When you feel tired and when you naturally wake up, but the circadian rhythm is much more entwined in health. Much of this pattern is gene controlled, but the environment, such as the light-dark cycle, can and will have an impact.
Eating habits and digestion
Not solely down to just your circadian rhythm, but the body uses specific fuels (sugars and fats) at specific times of the day. "Your body is best at digesting food/drinks when you are active and light is present. Thus, eating/drinking when your body expects you to sleep/rest, and it is dark, can disrupt this system and compromise metabolism." (Panda et al. 2019 p.579).
Rest, repair and recover
In the last 12 months, there has been more discussion and interest in giving the body a chance to rest. Not just limb rest but rest for your internal systems. One such area of interest is the gut microbiome - We now understand that the gut microbes also need a period of rest, to be honest, that includes all things related to metabolism, but concerning the gut, this allows the 'clean-up crew' to come out and clear away and cleanse the stomach lining. Think of it a bit like cleaning your kitchen. If you just left all the pots and pans the dirt would mount up and eventually cause you some hygiene and health problems. The 'clean-up crew' are there to minimise the leftover garbage from building up.
Time restricted feeding
It's not just about gut health, we now know that other systems such as the insulin response and sensitivity is improved when we observe a period of fasting. This is why time-restricted feeding (TRF) is gaining in popularity. Essentially, it's increasing the period of fasting or metabolic rest in your day. You would still consume your calorie requirements, but you eat and drink all your calories in a shorter period. For example, eating between 1000 & 1800 and nil by mouth for the remainder of the 24-hour period. Studies in animals and humans have seen multiple benefits from decreasing blood pressure, improved blood sugar, fat loss, diabetes control and wider cardiovascular improvements (Varady et al., 2022).
Dinner bell – when to eat
In addition to the daily eating duration, the time of eating also has a direct impact on our metabolism and health (Almoosawi et al., 2016). For example, grazing is related to a higher energy intake including night-time eating, not ideal for those wanting to lose weight. Furthermore, late-night eating is associated to an increased risk to obesity and coronary heart disease. This is more of a correlation than causation, as the reasons behind these less-than-favourable results are not fully understood (Paoli et al., 2019). One potential explanation is being out of sync with melatonin release – the hormone responsible for preparing the body for sleep. Imagine, asking for a meal in a restaurant after the kitchen being closed and cleaned for the day. Melatonin also reduces insulin release; not ideal if you have just consumed a meal near to bedtime. Possibly this adds gravitas to the famous saying by Adele Davis, “Eat breakfast like a king, lunch like a prince and dinner like a pauper.”
Key points
- Eat more of your calories earlier in the day
- Avoid eating late in the evening when melatonin levels are elevated
- If it works for you, try to incorporate some time-restricted feeding. Giving your internal mechanisms a chance to rest, recover and rebuild
- Build healthy habits that fine-tune your circadian rhythms – for example, a healthy sleep routine
If your sleep and recovery seem to be below par at the minute, maybe ZMA before bed could be the answer. Check out this article for more information.
As always, your diet is yours to own and these suggestions are based on the current research understanding, but we know that there is a huge amount of individuality regarding nutrition and your metabolism, notwithstanding your lifestyle, food intolerances, deficiency or restrictions, and of course finances. Eat well and be happy.
References
Almoosawi, S., Vingeliene, S., Karagounis, L. G., & Pot, G. K. (2016). Chrono-nutrition: a review of current evidence from observational studies on global trends in time-of-day of energy intake and its association with obesity. Proceedings of the Nutrition Society, 75(4), 487-500.
Haspel, J. A., Anafi, R., Brown, M. K., Cermakian, N., Depner, C., Desplats, P., ... & Solt, L. A. (2020). Perfect timing: circadian rhythms, sleep, and immunity—an NIH workshop summary. JCI insight, 5(1).
Manoogian, E. N., Chaix, A., & Panda, S. (2019). When to eat: the importance of eating patterns in health and disease. Journal of Biological Rhythms, 34(6), 579-581.
Paoli, A., Tinsley, G., Bianco, A., & Moro, T. (2019). The influence of meal frequency and timing on health in humans: the role of fasting. Nutrients, 11(4), 719.
Varady, K.A., Cienfuegos, S., Ezpeleta, M. et al. Clinical application of intermittent fasting for weight loss: progress and future directions. Nat Rev Endocrinol 18, 309–321 (2022). https://doi.org/10.1038/s41574-022-00638-x.
