When you eat is as important as what you eat.

One of the easiest ways to lose weight is to eat more earlier.

In fact, if you’d like chocolate cake, have it for breakfast.

(You’re more likely to burn it off that way).

Why is this so?

New research into our circadian rhythms shows that food is metabolised differently at different times of the day. Circadian rhythm is your body’s internal clock, a 24 hour cycle dictating when you are most alert and when you are ready for sleep, influencing various physiological processes. It’s interesting to consider your internal clock when it comes to nutrition, rest and recovery.

If you’re hankering for late-night cookies, just imagine slapping them onto your thighs and tummy. That’s right, calories consumed at night (that tend to be of the junk food variety) are more likely to be stored as body fat. After all, all you’re doing is going to bed afterwards…

Save that treat and enjoy it in the morning, when your body is primed for action and needs the fuel for energy. This is especially important if you’re trying to incorporate more exercise into your life. Be sure to eat enough during the day.

A good rule of thumb is to eat between eight and eight, that’s 8am and 8pm. So your body theoretically has 12 hours downtime to rest, repair and restore energy.

Regular Leither readers may remember my article on fasting from 2017. Stopping eating early-ish in the evening and not eating before bed really works. It means waking up hungrier for breakfast in the morning. Your ‘eating window’ shifts to earlier in the day. If you’re following intermittent fasting, it works better if you fast for a longer time overnight, rather than during the day (i.e. don’t skip breakfast).

I have found great success with this simple concept. It means you can eat pretty much what you want, as long as you’re mindful to “breakfast like a king/queen, lunch like a prince/princess, dine like a pauper.

That simply means your evening meal is not the largest of the day.

Ideally eat half of your calories by the end of lunch.

Enjoy a morning snack (something more than a coffee and sweet biscuit) to keep your blood sugar levels stabilised, especially important if you have a busy day or demanding job. Even if you just sit at a desk, your brain still uses 20% of your energy, so stable blood sugars and feeding your body during the day will aid concentration, memory and problem solving.

I find putting healthy snacks somewhere obvious helps. Put easy-to-eat food on your desk or in your work bag. Even if you WFH, place planned morning snacks on your kitchen counter where you’ll see them before scouring the fridge. The back bench in my fitness studio is often littered with snacks including fruit, oatcakes, dates, nuts and seeds.

The research into circadian rhythms and how different systems in the body are affected at different times of day is very new. Previously it had not been possible to accurately measure fluctuating hormone levels in the body over time. Published late last year, The Inner Clock: Living in Synch with our Circadian Rhythms by Lynne Peeples is an excellent, easy-to-read book. A more in-depth study by Russell Foster, Professor of Circadian Neuroscience, University of Oxford was published in 2022, Life Time: The New Science of the Body Clock, and how it can Revolutionize your Sleep and Health. It’s a hefty tome, but has a whole detailed chapter on the subject of Chrononutrition – nutrition and time.

Quoting from page 273: ‘By gaining a better understanding of our metabolism, and how our metabolic pathways are regulated by the circadian and sleep systems, we will be better armed to navigate the difficult path between healthy eating and metabolic syndrome… The relationship between the circadian system and metabolism is an emerging area of science, but already it is transforming our understanding’.

I’ve set up a Google alert for the phrase Chrononutrition and there’s more research being posted online every day. It’s gone from being a niche field of research to mainstream science.

Foster also tells us ‘The circadian system influences every aspect of metabolism, from hunger and digestion to the regulation of metabolic hormones. For example, under normal circumstances we eat during the day. So, no surprise, there is a circadian rhythm in saliva production that rises over the day and falls at night’.

In my mind, it’s connected with ‘intuitive eating’ where you learn to listen to the signals from your body as to when and what to refuel with. Minimising, or avoiding ultraprocessed foods (UPF) is important, as they can play havoc with your metabolic system.

To summarise Nature Journal, 26 March 2025: ‘Our findings suggest that eating later and having longer eating window are associated with higher dietary intake and higher BMI’.

In other words, eat more earlier and feel good. It’s official. ■

Info: www.griffenfitness.com

bluesky: tracygriffen