Intro to
Carbs, Insulin & Diabetes Nutrition
When I first started my training as a dietitian and nutritionist over 20 years ago now, I found diabetes very uninspiring as diabetes nutrition was just about cutting out sugar, and thankfully over the years since we have seen how much more there is to diabetes and its management which is why I decided to specialise as a diabetes nutritionist and dietitian.
Insulin resistance and hyperinsulinemia (high insulin levels) are the backbone of all the conditions I treat. As the name suggests insulin resistance is in essence the body cells becoming ‘resistant’ to insulin. As the cells struggle to respond to insulin, to compensate the pancreas produces more insulin leading to hyperinsulinemia. Insulin is a hormone produced by the pancreas and its roles in the body include promoting glucose (sugar) uptake, glucagon (sugar) storage, fat storage and sodium balance amongst other things. If insulin levels are out of balance it leads to fat storage – not only all over the body leading to weight gain, but also fat storage in body organs (where fat should not exist) such as the pancreas which leads to the development of diabetes. Hyperinsulinemia causes atherosclerosis which is a precursor to heart disease and stroke. As insulin is a growth factor it favours cancer cell growth increasing the risk of breast and colon cancer amongst others. Hyperinsulinemia is a serious condition but also something surprisingly simple to address.
Due to our common lifestyle choices of regularly eating over most of the day as well as following the government’s high carbohydrate, low fat diet our body is constantly having to deal with high glucose levels. Insulin is released to transport glucose into the liver and body cells, however these cells soon fill up with glucose from the high carbohydrate and sugary foods we eat. As further glucose enters the blood stream the already full cells have difficulty accepting any more glucose. In turn the pancreas produces even more insulin in essence to force the cells to take in more glucose, which works for a while. This persistently high insulin level is called hyperinsulinemia. Eventually the insulin can no longer force more glucose into the overstuffed cells so the glucose spills out into the blood – the start of diabetes. At this point it appears like our body is becoming ‘resistant’ to the effect of insulin as it seems the body is no longer responding to the insulin how it once did – this is called insulin resistance. Meanwhile due to the liver’s bursting glucose stores, it starts to convert the glucose into fat instead which is then transported out to the rest of the body for storage. If the influx of food and therefore fat production is greater than the livers ability to transport the fat out, then the fat soon builds up in the liver causing fatty liver disease – which is an unhealthy condition in its own right. As fat accumulates in the liver, insulin resistance escalates.
By this point weight may well be increasing. As the liver produces more and more fat it is stored around the body. Unfortunately this fat is not burnt off and used for energy due to the high insulin levels as insulin stops your body from tapping into your fat stores, instead it continuously promotes fat storage.
The fat stored around the body starts to infiltrate the pancreas, causing a fatty pancreas. The fatty pancreas can no longer function as it once did and can no longer keep producing insulin. At this point insulin production declines, glucose builds up further in the blood and type 2 diabetes is diagnosed.
Although not a standard feature in type 1 diabetes insulin resistance is becoming more common due to persistently high insulin doses.
In Poly Cystic Ovarian Syndrome (PCOS) high insulin levels and insulin resistance can lead to weight gain, increased testosterone which prevents ovulation as well as increased hair and acne and ultimately can increase the risk of type 2 diabetes in later life.
As you can see managing insulin levels is vital in managing pre-diabetes, diabetes, weight, PCOS as well as reducing the risk of heart disease and cancer.
The four main areas that have since been shown to be key in managing insulin levels and glucose levels are low or lower refined carbohydrate diets, weight loss (specifically from the liver and pancreas), fasting and promoting diverse and beneficial gut bacteria.
If you have insulin resistance, pre-diabetes or diabetes your body simply cannot control your blood glucose levels. Glucose levels are driven by carbohydrate intakes. Simply put, if you control the carbohydrate entering into your body then you control your blood glucose levels. The less you put in, the less they rise. Gone are the days of unhealthy lower carb ‘Atkin-style’ diets, the evidence is ever changing and we now have the knowledge and skills to formulate ‘healthy’, well balanced lower carbohydrate diets that has revolutionised the health of people worldwide.
With the medical model of managing diabetes the answer is to constantly increase medications or start insulin injections (which on average results in a 3kg or half a stone weight gain) to counteract the carbohydrate in the diet. Rather than take more medications and risk their side effects, why not just control the amount of carbohydrate and therefore glucose entering the bloodstream in the first place? Logical when you think about it! Thats where a diabetes nutritionist can really make a difference.
Low and lower carbohydrate diets vary in their carbohydrate content so can be personailised to you and your dietary preferences. Lower carb diets are not overly restricted and boring, cutting out all sweet treats and indulgences – unless of course you want to. Balance between health and enjoyment of life is always key to me.
We now understand how diabetes can be reversed by achieving a 10-15kg weight loss, especially if action is taken within the first 5 years of diagnosis, however this can still be done, although slightly less effectively even after the 5 year mark. This degree of weight loss is not small, but the key is this amount of weight loss sufficiently reduces fat deposits in the pancreas and liver which in turns allows the organs to function properly and reverse the diabetes.
If you are losing weight through the use of weight loss injections they can be exceptionally helpful. The risk however is if you come off the medication without having maintained your muscle mass as you lost weight and have not addressed the factors that resulted in the weight gain in the past. Use these medications with support for the best outcome.
Although weight loss is important there is newer evidence that even after having diabetes for 5 years it can be well controlled even if 10-15kg weight loss is not achieved, and this is through lower carb and fasting approaches. Weight loss is important but health can be enhanced even if weight remains high. We often get very hung up on weight which can be quite a negative place to be so as a diabetes nutritionist and dietitian I aim to work in a holistic manner, improving health as a whole.
Fasting is a natural part of our history as food was certainly not as plentiful as it was now. Unfortunately we have lost sight of this and now it is not uncommon to eat three meals as well as two to three snacks per day over 14hours of the 24 hour day. Bear in mind that each time we eat starchy, sugary or protein foods we get an insulin rise to promote glucose storage, which also promotes fat storage. Adding in fasts allows time for us to use our glucose stores as well as allowing our insulin levels to drop, and when insulin levels drop we can then also tap into our fat stores. Reducing fat stores not only reduces weight by using up fat stored under the skin, but most importantly also the dangerous visceral fat in and around the internal organs – which can help with the reversal of type 2 diabetes.
There are various fasting techniques – ranging from 16hour fasts 5-6 times a week to 36 hour fasts a couple of times a week and lots of variations in between. There are numerous other health benefits thought to arise from fasting, including reduced cancer risk.
It is also becoming evident that gut bacteria plays a fundamental role in our health, from weight management, development of diabetes and other chronic diseases as well as depression and other mental health disorders. We all respond incredibly differently when we consume carbohydrate containing foods due to out gut microbes, which further complicates diabetes management. One approach certainly does not work for all and is where individualised nutrition advice is key.
We understand that boosting our microbes through dietary changes can therefore be beneficial. Reaching the 30g of fibre a day and 30 different plant based foods each week recommendation has been linked with those people with the most beneficial gut bacteria. This may seem tricky when following a lower carbohydrate diet (if this is something you wish to do) as it most likely omits most common high fibre foods. This however is a misconception and high fibre and lower carb can work beautifully together.
Interestingly it has recently emerged that some sweeteners and sugar alternatives are not benign and depending on your gut microbes, can actually make diabetes control worse, not better. This is vital information I as a diabetes nutritionist will take into account when helping you work towards a lower carbohydrate diet – ensuring it is not a diet that negatively affects your gut bacteria.