Sunday, 6 March 2011

Diet #15, The Glycaemic Index Diet

I am pleased to have survived to the end of Diet #14, Diet Chef. This morning, I was 10st 1lb - so I lost 4lbs in a week - which is pretty impressive. I have to say, whilst I liked the breakfasts, and I tolerated the lunches, I wasn't keen on the dinners - although this might be to do with the fact that I took the vegetarian options, which were always going to be less interesting than the meat variety - and my aversion to microwave food in general.

On the plus side, this is great for teaching portion control, and the food is certainly "better" than - in as much as it's actual food - but I'm quite relieved to be coming to the end of this week. Happily, I'm lighter than I started, so on the basis of that making it a successful diet, job done.

I'm moving on to the GI diet (Glycaemic Index). The book is a "need to know" guide, and it does something that I'm beginning to notice is somewhat of a pattern amongst diet books. It starts off by "slagging off" other diets that you might have tried "some diets are restrictive, requiring dieters to eat quantities of one particular food, like cabbage soup {ooh, I forgot about that one}, grapefruit {tick} or pineapple {coincidentally, I did this one a year ago this week, in a desperate attempt to induce labour}. Others, more complicated, have recommended cutting out a whole group of foods, as the original Atkins did with Carbs”. According to this book, the latest news is that Atkins has filed for bankrupcy in the States - there has to be a joke there about losing pounds on Atkins, surely? The book regularly refers to research, to doctors and to nutritionists - but never with names or surveys, which makes it feel like they're trying to hide behind the "science".

Anyhow, how it works is simple enough – at least that's how it appears at the start... When you eat starchy carbohydrate food, like bread, cereal or pasta, your body digests the starch and turns it into glucose, which your body uses as a source of energy. Glucose enters the bloodstream rapidly (think alcohol on an empty stomach) and your glucose level shoots up. The danger is that it then crashes down just as quickly. So the aim is to eat foods that keep your blood sugar steady, avoiding the highs and lows. More recently, "scientists and researchers" began to realise that not all carbs produced blood sugar rushes, because some were broken down more slowly, and they started systematic testing. Foods with a low GI (under 55) break down more slowly, giving a slower rise in blood sugar and insulin levels. There are "good" and "bad" carbohydrates – and you have to eat more good and less bad.

But this is where it gets so complicated, to the point where I wish I'd done a degree in maths rather than history. Basically, according to the book, the limitations of this are that the Glycaemic Index of food is measured in 50g portions - but you'd need just 10 teaspoons of sugar to get 50g of carbs - whereas you'd need 5kg of broccoli to get the same 50g of carbs. So, these clever (but still unnamed) scientists added another facet - the Glycaemic Load (or GL). The GL is calculated by multiplying the GI value of the food concerned by the number of grams of carbohydrates it contains and then dividing the total amount by 100.

The book helpfully simplifies this as follows:

GI value x grams of carb per serving / 100 = GL value

Unfortunately, at this point, my brain, addled by weeks of dieting has exploded! I'll have another read of this book later today, and start this one tomorrow!

No comments:

Post a Comment