The Glycemic Load. The other half of the story.

The Glycemic Load. The other half of the story.

loaf of breadI have this conversation with clients at least once a week, so I thought I’d share it here for you as well. Now, while I’m an Exercise Physiologist (and not a dietician), the majority of our clients ask about dietary advice, as it’s part of the lifestyle behaviours that we often coach our clients through. We make sure that our advice stays within the scope of sharing general principles about food, supported by research from biochemistry and physiology.

So the question of ‘carbs’ intake comes up very often, as the message that a diet ‘lower in carbs’ leads to greater weight loss is well spread. This is the type of eating that I also stick to, for a number of reasons that I’ll get into later. But for now I want to address a significant part of this discussion that is often overlooked: The glycemic load (GL). Now, most people are aware of the glycemic index (GI), which relates to how quickly a food containing carbohydrate raises blood-glucose levels, depending on the type of carbohydrate chain involved. Typically, the quicker a food’s carbohydrate is broken down and absorbed into the bloodstream, the higher the GI.

The glycemic load estimates how much (rather than how fast) the food will raise a person’s blood glucose(sugar) levels after eating it. So it incorporates the GI, but very importantly, it also depends on the AMOUNT of carbohydrates the food contains!

So while a dark bread has a low glycemic index, due to the complexity of the carb chains, it has a high glycemic load, due to the many and long carbohydrate chains in it! So it provides a LOT of carbohydrate and calories. While the insulin spike won’t be high, it will be prolonged. its a slow cooker! In contrast, most vegetables will be both low GI and low GL, a perfect combination! in addition, they’ll be high in nutrient value (vitamins and minerals) as well as relatively lower in calories.

So don’t want to avoid carbs, but be aware of the total LOAD of the carbs you are eating, and make sure these match your personal energy requirements! LOAD up on the veges, and perhaps reduce the bread!


Sleep Deprivation: a road to diabetes

Sleep Deprivation: a road to diabetes

Did you get less than five and a half hours sleep last night?

There have been many times where I have, through meeting work deadlines, having a good night out with friends or through the “joys” of parenthood, and I have not given it a second thought.

That is until I discovered what it is doing to my health. (more…)

Exercise is inflammatory

This statement quite often leaves people somewhat confused especially after they’ve been told the impact chronic low-grade inflammation has on insulin resistance, which is a precursor to developing diabetes.

However, while an exercise bout does increase levels of pro- inflammatory messengers called cytokines it only tells part of the story. The above statement also challenges the concept that all inflammation is bad for us. This is certainly not the case. The fact that we are able to fight off viruses and infections is testament to the benefits of an acute inflammatory response mediated by our white blood cells.

You may have noticed that I’ve talked about acute inflammation (which implies a short term, high magnitude response) and chronic low-grade inflammation. It is the latter that we are finding is highly associated with chronic diseases of today which includes cardiovascular disease, arthritis, depression and diabetes.

However exercise appears to have an acute inflammatory response which in turn increases the production of free radicals which then switches on our body’s production of antioxidants that are ultimately responsible for the protective effect on our heart.

Further to this, the inflammatory response to exercise is mainly driven by a cytokine (or technically a myokine since it is produced in the muscle) called interleukin-6 (IL-6) which has been shown to suppress the effects of another pro-inflammatory cytokine called TNF-alpha. This cytokine is produced by sick adipose cells (storage cells for fat) and induces insulin resistance.  Exercise also increases the levels of anti-inflammatory cytokines (IL-1ra and IL-10) so while exercise might acutely create a pro-inflammatory response, the net effect after the bout of exercise is actually anti-inflammatory in nature.

So what are the take home messages here? Firstly a little bit of inflammation through exercise is good for you. A little bit of short-term stress only makes our systems stronger. Our body is an amazing machine that can adapt and respond to these challenges and it has many mechanisms to respond to these natural stresses.

Finally we need to understand that when our body is already under inflammation either acutely through sickness or chronically through diseases such as type II diabetes and arthritis, we need to choose intelligent exercise. By that I mean that the movement itself through poor biomechanics, or through an inappropriate intensity, should not introduce too much inflammation into the system. It is in these situations where we can experience adverse effects including excessive joint pain and musculoskeletal injuries.

Exercise benefits on Stress – fighting the beast!

Before we can make sense of how exercise can help us deal with stress better, it will be useful to understand the physiology of stress and how it affects us.
Needless to say, a great starting point is to highlight that the best way to deal with stress is to reduce your stress drivers and how you deal with them. Let us encourage you to look at those in your daily life and seek the support of qualified therapists in these area.

To support your changes, exercise is a great tool to improve your body’s capacity to absorb the effects of stress.
At a physiological level, stress is a desired response designed for a “fight or flight” situation. The physiological process that is triggered to help us deal with such an event is described below, but its important to keep in mind that it should occur over short durations, and then ‘dealt’ with (by fighting or running!).

The result is the release of adrenaline which is almost instantaneous and increases alertness and cortisol, which peaks at about 15-30 min after the start of the stress trigger. The whole point of these responses is to give us the required energy to deal with the situation at hand, by elevating blood pressure, increasing blood sugar (for energy) and decreasing most other non-essential systems. the problem in our modern western settings is that we don’t face too many ‘acute’ (short lasting) triggers (such as a threatening animal, etc), but rather longer lasting chronic stresses, such as work and financial pressures. In the ‘acute’ settings, increased physical activity was the way we dealt with the threat – i.e. by fighting or escaping – this would then help diffuse the physiological effects of stress mentioned above.

In our chronic western settings we don’t deal with stress in a physical manner. As a matter of fact we all well know that the amount of exercise we do is consistently decreasing, and even more so the busier we are. So we don’t often get to diffuse the heightened physiological responses. The result is chronically elevated levels of cortisol, which lead to Hypertension, Insulin resistance, and OBESITY.

So what is exercise good for? firstly it directly helps to reduce the physiological effects of stress, as we know that it will reduce insulin resistance, lead to hormonal responses that relax blood vessels, and use up excess blood sugar (and fat) for energy! Further more, through exercise the body becomes more physiologically efficient at dealing with the stress hormones in the first place. In addition you get all the emotional feel-good benefits of being active, a sense of achievement, and the opportunity to enjoy time doing something good for yourself!

so, don’t delay, get out there and MOVE!!!

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