Chrononutrition: Is When We Eat Just As Important As What We Eat? (Part 2.)

If you’ve read the first part to this article then please feel free to carry on… However, if you missed the first part then click here to get up to speed.

1. Breakfast like a king, lunch like a prince and dine like a pauper

We’ve heard it all before but how many of us really eat our biggest meal at breakfast? I know I definitely don’t.

Although, maybe it’s time we started eating more at breakfast and less throughout the day. Research suggests that eating more of your calories in the morning can have greater effects on weight loss than eating more of your calories in the evening. The study also showed that those who ate a larger breakfast reported being more satiated than those who ate a larger dinner. Eating late at night can increase Grhelin (the hunger hormone) and our desire for high fat, high sugar foods. 

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2. Genes

Genes do play a role in the release of Melatonin and the way in which we utilise food in the evening. There isn’t much more to say on this as I don’t suggest you start buying home testing kits. Unfortunately the science is not there to be able to support these yet. Although it’s interesting to note that our genes do have a role to play.

3. Gut health

There is a small amount of research to suggest that eating late at night, close to the time we’re looking to go to sleep can impair our gut microbiome even if the meal is a healthy one. We need more research on this area though to be able to conclude this for certain.

4. Exercise

Let’s be realistic here, we can’t all exercise at the exact time we want to and sometimes we’re lucky if we can fit it in at all. However, if you are someone who really struggles to sleep you may wish to consider exercising earlier on in the day as exercising right before bed may contribute to an impaired metabolic clock.

5. Caffeine

If you’re familiar with some of my work then this shouldn’t be a surprise to you! I’m forever banging on about not drinking caffeine after 2pm. Caffeine can really impair our internal body clock and delay the onset of Melatonin. As a result try ensure you’re last caffeinated drink is around 2pm and switch to a herbal variety from then on.

So there you have a whistle stop tour of chrononutrition and whether when we eat is as important as what we eat. In an ideal world we might all want to time our meals perfectly although let’s be realistic we don’t live in an ideal world and so I think it’s easier to make healthier choices than strategically plan the timing of your food intake. Hopefully this information can help you make some healthier choices although please be sure not to play havoc with your social lives too!


Morgan, L. M., Shi, J. W., Hampton, S. M., & Frost, G. (2012). Effect of meal timing and glycaemic index on glucose control and insulin secretion in healthy volunteers. British Journal of Nutrition, 108(7), 1286-1291.
Jakubowicz, D., Barnea, M., Wainstein, J., & Froy, O. (2013). High caloric intake at breakfast vs. dinner differentially influences weight loss of overweight and obese women. Obesity, 21(12), 2504-2512.Asher, G., & Sassone-Corsi, P. (2015).
Time for food: the intimate interplay between nutrition, metabolism, and the circadian clock. Cell, 161(1), 84-92.Bonham, M. P., Bonnell, E. K., & Huggins, C. E. (2016).
Energy intake of shift workers compared to fixed day workers: A systematic review and meta-analysis. Chronobiology international, 33(8), 1086-1100.

Chrononutrition: Is When We Eat Just As Important As What We Eat? (Part 1.)

For those of you who follow me on Instagram (@jennahopenutrition) you’ll know that I recently went to a conference on meal timing and overall health. I shared a small amount of information from the conference but as so many of you had questions I’ve decided to write an article in more detail.


So, to start with what exactly is Chrononutrition? Chrononutrition is the relationship between our circadian rhythms (our body’s internal natural clock) and our dietary intakes. Realistically our body’s internal natural clock is always being interfered with by external environmental cues. This is referred to as our diurnal clock. These environmental cues include: light, meal times, sleep, exercise and social interaction to name a few but light having the greatest affect.

To some degree we can’t escape from these external cues but we can help to limit their impact through a consistent daily routine.


So now we have the background of our circadian and diurnal clocks let’s discuss the impact of nutrition and meal timings on these.

Below I’ve listed a few of the take home messages:

 1. Eat dinner at least 2.5 hours before you go to bed.

Eating later in the evening may affect your body’s ability to clear plasma TAG (fatty acids in the blood) and plasma glucose (sugar in the blood).

When fatty acids take longer to clear there is an increased risk of the production of low density lipoproteins (more commonly known as bad cholesterol). Fatty acids in the blood are normally increased at night so when you’re adding more to them by eating late you’re reducing the body’s metabolic control.

 So your next question is likely to be… So what time is the latest I should eat?

Like always we are all different and there is no set answer. Although, we know that ‘late owls’ e.g. people who truly can’t sleep before 1am can eat later as their melatonin (sleep hormone) isn’t released until later on in the evening. Alternatively if you’re anything like me (who needs to be in bed by 10pm) then you’ll need to eat earlier on in the evening before your melatonin in released. Ideally I’d suggest around 6-7pm.


2. Eat your carbohydrates earlier on in the day

So I have to be honest - the research in the past has been fairly conflicting. Before I get attacked and whilst this might not work for everyone, I’m here to share the research from the conference so here goes…

 Let’s chat carbohydrates for a second. Fruit, vegetables, legumes, beans, refined grains, whole grains and sugar all fall under the category of carbohydrates. When I’m talking about carbs here I’m referring to the type which will cause a greater spike in your blood sugar. This means the white kind; sugar and even particularly starchy vegetables such as sweet potato, pumpkin and parsnips which when cooked can cause greater spikes in blood sugar.

 So back to meal timings… It’s a similar picture when it comes to the sugars. Sugars take longer to clear from the blood at night. When this occurs regularly over a prolonged period of time there’s an increased risk of type 2 diabetes.

Interestingly research has shown that eating a high glycemic index dinner had a greater effect on blood sugar than a high glycemic index breakfast. In other words sugar has different effects on your blood sugar levels when consumed in the morning to the evening.

 More specifically carbohydrates consumed in the evening can create a greater blood sugar spike than those consumed in the morning.

 As a result it is advised that you eat your carbohydrates for earlier on in the day and consume a low GI meal in the evening. So what does this mean in practical terms?

 Rather than having a bowl of pasta or a pizza for dinner opt for some fish or meat and veggies, tofu stir-fry or lentil bolognaise over courgetti. Alternatively swap your white rice for brown or cauliflower rice to help lower the glycemic index of the meal.

Please note: this is not to suggest that carbohydrates are bad it’s simply to ask you to think about the time you might be consuming them especially if you’re having problems with your sleep.

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3. Shift workers

Shift workers are an interesting group in the world of nutrition as their meal times, food choices and overall health often poses very different findings to those who are on regular working patterns. Research has found that shift workers have less interest in picking healthier food choices and consume more sugar and caffeine (although they may not be eating more calories). This may cause an increased risk in health related diseases. Although the good news is that if shifts have a predictable pattern it is possible to help improve overall health. Adaptation is easier as melatonin release may become more regular and predictable.

As there’s so much to say on this subject I’ve broken it into two sections so click here for part 2.

Why This One Food Is So Underrated....

We might only be in Autumn but the weather is doing some weird things at the moment. When the chill hits it’s common for us to seek more hearty, warming foods. As a result I’ve decided to dedicate this week to the one and only understated soup… Bare with me. In the past, soup has often been regarded as the ‘low calorie’ option, maybe for weight loss, but this meal option can be packed with a ton of nutrients and healthy ingredients to make it super filling to keep you going. You can either get this very right or very wrong. So let’s chat how to get it right…

Although we typically think of soup as veg and water we actually need to ensure it’s nutritionally balanced.


Vegetables: this contributes as part of the carbohydrates especially if they’re starchy veg. Although you could also add quinoa or brown rice to bulk it out.


Next you need to add your proteins and healthy fats. Your protein of protein can be gained from lentils, beans, chickpeas or peas. You can also add some extra chicken too.

The fats can come from avocado oil (used for cooking), cheese or tahini drizzled on top.

If you’re buying pre bought soup I recommend to watch out for added sugars. I mean who needs sugar in their soup?!


Soup is a great source of fibre (as most people struggle to hit the recommendations of 30g.d) and the perfect way to pack in your vegetable requirements. It’s easy, warming, delicious and easy to digest. I recommend bulk cooking a batch and then keeping it in the freezer for when you need it. 
If you’re super keen, you can make it using homemade bone broth to pack in the nutrients and for an extra collagen hit.

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Having said all of this you’re probably not alone if the idea of a bowl of soup doesn’t tickle your fancy. So let’s chat spicing it up….

How you can pimp your soup?
⁃ Add a dollop of natural yoghurt on top to give creaminess (and extra protein).
⁃ Top with some chopped fresh herbs, maybe some coriander on your sweet potato soup, or some basil on your tomato soup. 
⁃ Sprinkle on some toasted nuts and seeds
⁃ Serve with a thick slice of rye bread; this is perfect to dunk and provide a good source of slow release carbohydrates 
⁃Try garnishing with thinly sliced spring onion or chilli 
⁃ Make it chunky! Try opting for a chunky soup for some added texture. Alternatively, try adding a handful of fresh spinach or frozen peas in while your heating it.

Hopefully this has given you enough reasons to jump on the band wagon and swap out those summer salads for something a little more warming this winter.