By Nadia Marshall
When I googled ‘Low GI diet’, the first thing that came up was a sponsored advertisement for Special K! This is a pretty good indication that everyone has heard of this diet. If the food marketers are using it to sell stuff, it is clearly a big deal! Like many other diets, the ‘Low GI’ diet feels a bit like a fad but this approach to eating has actually been around for about 20 years. But what is it all about and how does it relate to the Ayurvedic approach to eating? Lets have a little look...
What is the Low GI Diet?
GI stands for ‘Glycemic Index’ which is a measure of the effect of dietary carbohydrates on blood sugar levels. It is a scale from 0-100 that estimates how much each gram of available carbohydrate in a food raises a person's blood glucose level in the two hours after eating, relative to the consumption of glucose. It was developed and popularised in Canada – researched by a Canadian Professor of Nutrition, Dr David Jenkins and turned into a successful line of diet books by Ontario Heart & Stroke Foundation President, Rick Gallop.
It is said that low GI foods (with a GI of 55 or less) create a slow, steady rise in blood sugar followed by a slow, steady fall. On the other hand, high GI foods (with a GI of 70 or more) create fast, dramatic rises in blood sugar followed by epic crashes. Medium GI foods (56-69) have an effect somewhere in the middle.
Carbohydrate Metabolism
To understand GI you need to know a teeny bit about the metabolism of carbohydrates (GI relates solely to glucose so I won’t mention the metabolism of other monosaccharides, like fructose). Here is a super simplified crash course....
When we eat carbohydrates they are digested in the gut and the monosaccharide molecules of glucose are absorbed into our blood stream. As a result, our blood sugar rises. Our body in all its homeostatic wisdom, recognises this and causes our pancreas to produce the hormone insulin which is like a ‘glucose mop’. Insulin tells our tissue cells to take up glucose from circulation and use it for energy, tells our liver cells to store glucose in the form of glycogen and tells our adipose tissue cells to store it in the form of fat. When insulin levels drop, its absence then has the opposite effect – the glucose-uptake of cells is switched off, the liver cells begin to break down glycogen back into glucose, glucose is released into circulation by some cells and fats are released from lipid storage.
The faster and higher our rise in blood sugar, the more excessive the response and the more dramatic the clean up. This is why we can swing from high blood sugar to low blood sugar in a matter of hours. When glucose is released more gradually, the clean up is also more gradual and relaxed and the variation in blood sugar less intense. Our dietary intake of carbohydrates is the main determinant of our blood sugar levels. So what we eat (and drink) matters more than anything else when it comes to regulating blood sugar....
The Problem with High GI Diets
High GI diets are believed to be bad news. They are damaging to our arteries and blood vessels and put a big strain on our pancreas, liver and insulin–receptors. This is why high GI diets have been linked to heart disease and diabetes. The most common type of diabetes (type 2) occurs as a result of insulin resistance. Our body may still produce insulin but our insulin receptors no longer pick it up. The key (insulin) no longer works because the locks (insulin receptors) have been worn out from glucose walking through the door so much! This form of diabetes used to be an adult-onset disease but more and more, due to terrible diets, kids and teenagers are starting to suffer from it too...
Of equal or perhaps even greater concern is the effect that high GI diets have on our brains. Most of the cells in our body can get their energy from a variety of sources. Our brains are much pickier. They feed almost exclusively off of glucose. So the availability of glucose has a huge impact on our brain. When we have a spike in our blood sugar, it creates an instant natural high. I think we’ve all seen this in children after a birthday party. But what goes up, must come down. And it usually comes down pretty quickly. When we get lows in blood sugar it can result in instant fatigue, headaches, irritability and cravings, hyperactivity, depression and inattention. This behaviour is particularly pronounced in kids. If you think your child has ‘behavioural problems’, maybe take a closer look at the GI of their diet – it might be the problem instead.
High GI diets are also said to have an impact on our waistlines. As we now know, insulin is responsible for turning excess sugar into fat. So, if we eat high GI meals all the time, it may be the cause of our weightgain. Insulin is also an appetite stimulant so the more we produce, the more we want to eat! You can see why high GI diets can turn us into efficient weight-gain machines.... harvesting fat out of sugar and craving more and more food at the same time!
Apparently, they also make us age faster. High GI meals lead to the creation of more free radicals and can also cause a thing called ‘cross-linking’ with protein cells. Collagen fibres are particularly susceptible to cross-linking, which causes them to lose flexibility, become brittle and breakdown. Let me translate this. High GI diets cause wrinkles, less mobility in the joints, decreased lung capacity, reduced oxygenation of the tissues and stiffening of the blood vessels!
The thing about high GI diets is they create a vicious cycle. When our blood sugar crashes, we are driven to search for more sugar and in this sugar-searching frenzy we tend to make poor choices, eat more high GI foods and inevitably create a spike/crash cycle all over again! We have to get off the merry-go-round.
High GI vs Low GI Foods
So by now you might be wondering... what are high GI foods? Well, you can access a variety of lists telling you what foods are low, medium and high GI but I think it is better that you understand what makes a food high GI so you can work it out for yourself to some extent.
Because GI relates to the metabolism of glucose, foods that contain more readily available glucose will have a higher GI. But it is a little more complicated than that. The digestion of sugar is dramatically influenced by the package it comes in. The things that slow down the digestion of sugar are the presence of PROTEIN, FIBRE, FAT and ACIDITY.
So, if a food is naturally rather starchy and has low protein, it will have a higher GI. If a food has been highly processed (e.g. milled, ground, puffed, flaked, popped or extruded) and/or had its fibre removed, it will have a higher GI. And if a food has had all of its fat removed, it will also have a higher GI. This means our highly processed, low fat foods and sugary drinks that line the shelves of our supermarkets are pretty bad news from a GI perspective.
White flour, white-sugar, processed cereals, most breads (especially baguettes, bagels and white bread), rice cakes, rice crackers, rice noodles, fast-cook varieties of rice and oats, popcorn, boiled sweets, jelly beans, spongy cakes, sports drinks and soft drinks are all high GI and should generally be avoided.
The Problems with this Approach
The main problem with this approach is people can easily become fixated with the GI value of foods or ingredients rather than considering the GI of a whole meal. As a result, they might stop eating dates, pumpkins or watermelon. This is missing the point but is an easy trap to fall into when looking at charts and numbers. It is important to remember when exploring this approach that when you cook and serve foods together, it affects the GI of the whole meal, particularly if you are introducing PROTEIN, FIBRE, FAT or ACIDITY.
The next big problem with the approach is it ignores what is happening in the body once the high or low GI foods are consumed. In a more recent study, it has been shown that gut bacteria play an enormous role in our ability to digest sugar. If we have a healthy biome, we may beable to digest high GI foods without the big spikes in blood sugar while if we have a unhealthy biome, even low GI foods might lead to blood sugar spikes (1). Never forget the gut bugs!
Another problem with this approach is that it is only looking at one thing – glucose and the effect it has on blood sugar. So, it is a reductionist approach. And with all reductionist approaches, there is a ‘bad guy’ and a ‘good guy’. But the ‘good guy’ isn’t necessarily good if you’re looking at it from another reductionist perspective. For example, meat is low GI because it contains no carbohydrate. So in your eagerness to go low GI you might cut out carbs and eat mostly protein. This is ‘good’ from a GI perspective... but ‘bad’ from an Alkaline perspective. Or in your enthusiasm to go low GI you may cut out high-glucose sweeteners and replace them with high- fructose sweeteners (like agave nectar) because fructose doesn’t create an insulin response so has a low GI. This may be ‘good’ from a GI perspective... but is ‘bad’ from the No-Fructose perspective. No wonder everyone is so freaking confused!
One big problem with the low GI diet plans I’ve looked at is their interpretation of the idea of combining carbs and proteins to slow down the digestion of the carbs. The addition of proteins like cheese, eggs and meat to most meals will definitely slow down the digestion of sugars but it will also likely slow down your digestion altogether! These heavy foods are very difficult to digest and if eaten all the time will imbalance you Agni, create Ama and potentially start of all manner of disease processes. Lets just say there is a better way of combining foods to make them lower GI that still keeps things light and easy to digest...
Another less interesting problem with this approach is the creation of the charts. Some of them have been measured with glucose as the base measure while others used white bread. So the charts tend to differ a bit which is confusing. In fact, GI values generally can be very confusing given the GI of a single food or product can vary enormously! Take rice for example. The GI of rice can be anywhere between 48 (red basmati rice) and 98 (jasmine rice) depending on the type and brand of rice, how it is cooked and for how long it is cooked! Also, a GI value tells you how rapidly a carbohydrate turns into glucose but it doesn’t tell you how much of that carbohydrate is in a serving of a particular food. You need another measure – Glycemic Load (GL) to get the full picture. So to know anything at all, you really need to keep track of two measurements! My head is spinning just thinking about it.
I should mention (like Wikipedia cleverly did) that the GI measure can make certain foods like rice and potatoes out to be the bad guys in terms of diabetes and heart disease. BUT... there are cultures in the world who virtually live on these foods and have non-existent rates of diabetes and heart disease. So perhaps there is a little more to the story than just GI??
And finally, I'd like to pose a controversial question. I get that high GI meals are bad news but with that understanding comes the natural assumption that the lower the GI the better. I'd like to ask if this is actually correct? For example, if we do a lot of 'head work' (i.e. need to think a lot for our work) wouldn't it be more ideal to have a Medium - Low GI diet rather than a super Low one? Afterall, if an active brain uses 22 times more energy than active muscles, it is going to need a bit of glucose during the day to get things done. Perhaps sitting at your desk in the middle of the day with a belly full of protein and fibre, unable to access much glucose at all isn't great either? I know if I had a slab of flesh for lunch all I'd want to do is sleep afterwards. Perhaps the middle-way is more appropriate for the cerebral species that we are? I'm just asking....
The Benefits of this Approach
I think this approach is a valuable tool for the people it was originally designed for - people with diabetes who need to very closely control their insulin responses. If you are at risk of developing diabetes or have a history of diabetes in your family (like me), you should maybe look into it and make some adjustments to your diet.
Beyond that, I think the main benefit of this approach is it could discourage parents from feeding their children processed cereal for breakfast, knowing that they will crash and burn within two hours... just in time for arriving at school. It might also stop people from living off of rice cakes, white bread, white sugar and soft drinks. That can only be a good thing. And... it may encourage people to eat more legumes and pulses, fresh fruits and vegetables, some more healthy fats and to branch out and try some different grains.
But I think the main potential benefit of this approach is to bring people’s awareness and attention to their blood sugar (although this wasn't actually mentioned in anything I read about Low GI diets!). Blood sugar isn’t just an abstract scientific concept. It is something we can all feel. The more mindful we are of our bodies and our digestion, the more easily we can discover for ourselves how our blood sugar is travelling, how it affects our minds and what subtle changes we can make each day to have a more stabilising effect. Actually, when we’re first starting out these changes aren’t subtle at all. They probably involve eating more regularly and eating less junk. But as we progress on the journey, they may become more subtle... like deciding to add a sprinkle of nuts to our raggi porridge so it lasts longer in our tummies.
Ayurvedic Diets vs Low GI Diet
Because the Low GI approach is a reductionist bio-mechanical dietary approach it is difficult to compare it to Ayurvedic diets which are broad and holistic with bio-mechanical, bio- energetic and bio-spiritual considerations. If you’re wandering what on earth I mean by that fancy sentence, then let me rephrase it...
Low GI diets only look at one aspect of eating – the response that certain individual foods have on our blood sugar. Ayurvedic diets consider a lot more than that. They look at the effect food has on our body and physiology through its taste, heating/cooling effect, post- digestive and specific medicinal effect.... and they consider the effect food has on our mind through its Sattvic/Rajasic or Tamasic nature. They consider how foods work together and how combining foods can change their effect on the body. They also deeply consider how easy or difficult a food is to digest and how it can be prepared and cooked in a way to make it easier to digest.
So the question is... are Low GI diets Ayurvedic? No, not at all. But are Ayurvedic diets Low GI? Yes! Or at least they are Low-Medium.
But why? Well, remember that the highest GI foods are foods that have been highly processed. When beginning any Ayurvedic diet, the first step is to stop eating processed and pre-cooked meals and to start cooking more at home, from scratch, using fresh, whole, preferably organic ingredients. So instantly you’re eating food with more fibre, less processed sugar and more healthy fat .... making it all lower GI. You also avoid soft drinks, sports drinks and alcohol and eat hardly any bread or potatoes – some of the high GI culprits in an average western diet.
In terms of basic ingredients, you eat a lot of legumes and pulses (all low GI). You eat predominantly vegetarian food so have a lot of veggies, salads at lunch and fresh fruit between meals (all low GI). You eat unprocessed dairy products and less refined sugars like jaggery that are digested more slowly and have a lower GI than their processed counterparts. And you start eating more healthy oils like ghee, sunflower, sesame and olive oil in all of your meals (lowering their GI). In terms of grains, you eat a variety of wholegrains including white basmati (medium GI) and red basmati rice (low GI), bulgar wheat, barley, oats, buckwheat and quinoa (all low GI) as well as raggi, polenta, couscous and semolina (medium- high GI). In terms of flours, you use atta whole wheat, rice, mung, besan (chickpea) and buckwheat flours, often combining the higher and lower GI flours together. You also use a large amount of spices, some of which are traditionally used in the prevention and treatment of diabetes including ginger, turmeric, cinnamon and fenugreek seeds.
But the most important aspect when it comes to considering the GI of Ayurvedic diets is the preparation and combining of these ingredients! Afterall it is the marrying of ingredients that makes the GI or a meal... not its individual parts.
With your Ayurvedic breakies you're usually frying a grain (CARB) off in a little ghee (FAT) then adding full-cream milk (PROTEIN/FAT), spices, jaggery and a sprinkle of nuts (PROTEIN/FAT) to make a delicious porridge; all lowering the GI of the original grain, whatever it may be. For lunch you’re usually combining a grain (CARB) with a legume/pulse (PROTEIN) then having some veggies/salad (FIBRE) on the side with some ghee (FAT) and lemon juice (ACIDITY) on top. This makes a lovely low GI meal. And for dinner, you often have a lighter meal like kicharee or a veggie soup with a wholewheat chappati (low GI) or other grain on the side. Again all low GI... but also light and easy to digest at the same time. So you can see, Ayurvedic diets tend to be naturally low to medium GI without really trying...
Of course, all of the above relates to an average tridoshic Ayurvedic diet. If you were suffering from diabetes, any pre- cursor symptoms of diabetes or any other related imbalances and saw an Ayurvedic practitioner, you would be given a very specific diet – favouring certain legumes, pulses, grains, fats and spices and avoiding others to make your food even more appropriate for your state of imbalance.
Conclusion
After considering Low GI diets and researching this approach for the last few weeks, I’m actually pretty bored and can’t wait to stop thinking about it. Perhaps this is the biggest problem with the approach... for me, anyway. It tends to narrow your focus down to analysing individual ingredients and numbers on a chart. This immediately has you judging and measuring your food, your meals... and yourself. I don’t know about you, but I do enough of that already.
I personally prefer an approach that has the potential to take me out of my head... and into my body and belly; into how my food actually makes me feel; into the colours, flavours, textures and personalities of my food; into my relationship with food and its relationship with me. For me, Ayurveda has done this beautifully. Having said that, learning more about GI has inspired me to tweak things a little and to spend a little more time with all the different, delicious grains sitting on the shelf that I've been neglecting for a while...
Low GI Diets: An Ayurvedic Review
