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15 Mar, 2023

How food works with our body with nutritional therapist Phoebe Liebling

Our nutrition expert Phoebe unpacks how food really works with our body and the science behind how eating different foods in different combinations makes us feel a certain way.


Most of us will be quite aware that eating in a particular way is likely to make us feel & function better than if we were to consume different food & drink at different times in different combinations. Which is great. Confirmation that our choices are suiting us is always a great bolster to keep doing these things, but the bit that tends to really cement such habits into our routines is an understanding of why.

So join us as we now delve into the ultimate question….what actually happens when we eat?! I’d love to say I have time today to fully explore human physiology in all its facets but I’d literally have to write you a book, so instead we are going to hone in on the hot topic of blood sugar regulation.

A key point before I get started that I just wanted to mention is Vitamin D. We talk about Vitamin D for a great many reasons but an insufficient status will always compromise our ability to regulate our blood sugar levels. So if on reading this you suspect your blood glucose is fluctuating and you don’t know your Vitamin D status then I’d advise getting it checked. A level of 80-120 nmol/litre would be my goal for someone.

Right, with that under our belts let’s talk food!

When we eat carbohydrates, all our wholegrains like brown rice, bulgur wheat, grain based breads, pastas, potatoes, root vegetables, beans, pulses and fruit, we are consuming sugar molecules bonded together in chains of varying lengths. Complex carbohydrates, or starches as they are also known, are longer, tougher chains to get into, whereas simple sugars are more easily accessed because they might only have 1 or 2 bonds that need breaking to get at the energy they contain.

Sugars can also be called things like mono, di or polysaccharides, which basically numbers the bonds that they contain. Mono is 1, di is 2 and poly being a handful. This would compare to the starches which have bonds counted in 10s. But whenever we eat a carbohydrate our body wants to break as many of those bonds as possible because those individual sugar molecules that make them up are your little energy nuggets. These are glucose molecules and they pass into your bloodstream to then travel to every cell in your body feeding into your cellular energy metabolism which is what powers your body to do all of the things it needs to.

The thing about sugar molecules is they are literal firecrackers and so your body has a really strict range of how many can be present in the blood at any one time. Too much and you will cause oxidative damage to your tissues so we have a hormone called insulin that responds to put extra sugar based energy into storage when levels rise too high, either as glycogen in muscle/liver cells, or as fat if these stores are full. Similarly, there is a danger to too little sugar being present in the blood as you will be unable to support your body to function properly so you have an antagonistic (opposite) hormone called glucagon that will liberate stored glycogen to be put back into circulation.

This is all very normal and we will naturally fluctuate in a gentle pattern over the day when we eat, but the concern is that the ‘danger’ responses from too much or too little circulating sugar are only meant to be used once in a while but a lot of people will now be relying on them all the time. At this point I also want to clarify that there are certain things other than eating carbohydrates that will change blood sugar levels.

  1. Stress. Stress hormones and blood sugar are very closely intertwined, the presence of either adrenaline or cortisol in the blood will automatically raise blood sugar levels as your body believes it needs additional quick energy available to do something.
  2. Sleep. Poor sleep will too raise your blood sugar, and here’s the kicker - poor blood sugar regulation is a stressor in itself which is why many will struggle to break the cycle of blood sugar issues as they look for a linear solution when actually it's really a spiral of sorts. Now cortisol is naturally produced in the morning as part of our waking up, so our blood sugar and consequently insulin levels are always going to be higher in the morning. This is the reason people like myself will impress the importance of a well balanced breakfast because your body is going to be more reactive to the first food you eat on any day. It can be a positive, well managed and sustained response, or you could kick off a rollercoaster for the next 24 hours. And yes I mean 24 because anything that happens to your blood sugar when you are awake will also happen whilst you are asleep which is that viscous cycle I just mentioned because a disturbed night sleep means more cortisol on waking which means higher blood sugar that day and thus the cycle continues.

The key takeaway from this being that:

  • Managing your stress levels and prioritising good sleep are key fundamentals to ensure good blood sugar regulation.
  • We always want to include 30-40g of protein in our 1st meal of the day.
  • Ideally picking something savoury not sweet, and if we are including carbohydrates choose complex rather than simple ones.
  • Eggs on whole grain toast with some veg, organic yoghurt with nuts, seeds & a sprinkle of oats + cinnamon, or pancakes made from egg, a whole grain flour and spinach with pesto & avocado would be good examples. Vegan pancakes made with chickpea flour or protein powder + flaxseed are nice options too.

I hope at this stage I haven’t demonised insulin too much because it is incredibly important and forms part of your natural blood glucose metabolism as well as your safety net situation. When your blood sugar is in range you still have a small amount of circulating insulin present, and this acts to open little metaphorical doors in your cell membranes to allow glucose to pass in and fuel up those mini furnaces within our cells (mitochondria) that are keeping us firing on all cylinders. What happens when your blood sugar fluctuates too frequently/acutely however is your insulin levels remain raised and so those little doors forget to pay attention to their knocks because they’re happening all the time. This is what we would call insulin resistance and if it’s left unchecked will eventually turn into Type II diabetes.

A couple of key things here would be to concentrate on your magnesium & omega 3 intake as these nutrients help your body to use insulin more effectively by resensitising cell membranes to its action. Back to my metaphor here - it reminds them to listen for the knocks on the door.

  • Magnesium is found naturally in whole grains, dark green leafy vegetables, beans, pulses, lentils, nuts & seeds however there is a concern that modern day soil depletion means that our food isn’t as rich in minerals as it once was. So even those following a wonderfully varied diet might need a top up. In clinical trials a daily dose of 250-450mg of magnesium was proven to lower fasting blood glucose levels compared to placebo, so if you’re looking to supplement then aim for that level, either as a magnesium ascorbate, bisglycinate or malate. The other key benefit to mention in terms of this picture as a whole is that magnesium is key for mitigating the impact of stress on the body and aids good sleep, so if you were to pick 1 key player to hedge your bets on then magnesium could very well be it.
  • Omega 3 would then be present in oily fish, flaxseed & hemp seed oil as well as a variety of supplements depending on whether you consume animal products or not. The recommendation is to aim for 3-4 servings of small oily fish per week, and/or 1-2 tablespoons of cold pressed flaxseed or hemp seed oil daily to meet your requirement.


As a final angle to be aware of, there is a defined link between reproductive hormones and blood sugar levels. For those who need a refresher the menstrual cycle starts on day 1 with the 1st day of a woman’s period. This is referred to as the follicular phase and runs for the first 12-14 days until she ovulates, from then you have the luteal phase which runs until the start of her next period. In the follicular phase oestrogen is the dominant hormone whereas progesterone is dominant in the luteal phase. Higher progesterone levels make a woman naturally more insulin resistant which is why they will feel hungrier, crave more sweets and carbohydrates, and actually just need more food generally in the week or so before their menstrual bleed.

Increasing antioxidant levels through more colourful variety in their diet, maybe adding in plenty of targeted options like turmeric, limiting stimulants and prioritising sleep helps to prevent that natural switch in blood sugar sensitivity from becoming an issue.

Those who don’t adapt their routine will often find they are more perturbed by their cycle than those who vary their habits depending on their dominant hormone status. I will always impress the importance to female clients that they adapt their exercise to prevent that interplay between stress hormones and high insulin I described at the beginning. More dynamic when oestrogen is high and much more calming when progesterone is in control.

Need a way to perfectly balance your sugar levels and feel your best without having to think about it? Our meals are perfectly balanced to provide all the essential nutrients you need to work with your body and make the healthy choice the easy choice. Discover our options here.

PHOEBE LIEBLING Nutritional Therapist & Clinical DirectorBSc (Hons) DipNT, mBANT, mNNA, CNHC registered, GNC registered
Discover more of Phoebe's work here: Natural Nourishment