In my first 18 weeks eating a low glycemic index diet, I lost 22 pounds. Let me clear up a few things, I was not a junk food obsessed maniac living off potato chips prior to this. I watched my diet quite carefully, ate as low fat as was reasonable, and worked out several times per week. After switching from low fat to low glycemic index, I noticed an almost immediate change. In the first four weeks I lost seven pounds, this was even after eating out several times, going to a few bars, and having a weekend away in Vancouver.
What is a low glycemic index diet? Essentially, it is a diet in which you limit foods that are easily digested and quickly affect your blood sugar levels. The theory behind a low glycemic index diet is that foods that are easily digested cause a sudden spike in your blood sugar level. This spike is fairly unnatural compared to traditional diets (i.e. what people ate hundreds of years ago), and results in your body releasing large amounts of insulin to bring your blood sugar level back to normal levels. Typically, insulin overshoots the mark leaving the body low on energy, and thus hungry (as well as miserable!). There is more to it than this, but this is the jist of it. Eat sugar and you get lots of calories and you are hungry a short time later, eat vegetables or protein and you get fewer calories and are fuller for longer.
When I started, I had been tracking my weight for four years, and my first month on this diet was the most I've lost in one month aside from my trips to Nepal and Syria/Jordan. Within two weeks I felt this diet was working for me. Unlike other diets I've tried in the past, the feedback seems to be almost immediate. If I abide by the diet, my weight is the same or down the next day. If I cheat on it, my weight is up. With that kind of feedback it makes it much easier. Also, while it took some getting used to, in many ways it is easier than eating low-fat (which I had been doing as long as I can remember). For instance, cheese, steak, avocados, omelettes, small amounts of ice cream (only the really rich creamy ones), nuts and olive oil are all okay on this diet. I haven't felt hungry, in fact, it's really been the opposite. Right from the start I was bringing parts of my lunch home because I couldn't finish it, or forgetting to eat part of my breakfast.
The measure of how fast a food raises your blood sugar is referred to as a "glycemic index". By definition, glucose is 100. Foods that cause a slower increase in blood sugar have a lower glycemic index (e.g. peanuts = 15). Believe it or not, there are foods with a glycemic index worse than 100, for instance beer comes in around 110. I found this very interesting since I pretty much accept as fact that beer is very fattening, but I've never felt it was properly explained before.
With a low glycemic index diet, there is no one food group that must be avoided entirely. Certainly carbohydrates are singled out as a food group to be cautious about, but certain carbohydrates are allowed (such as brown rice, whole wheat pasta, triscuits, green vegetables, etc.). Generally, it is more of a guideline as to how to eat more like people did hundreds of years ago.
Within three people in my family, a combined total of over 100 pounds was lost in under six months by following low glycemic index diets. For me, my blood pressure dropped from borderline high, to slightly below normal.
There are a number of other advantages to eating a low glycemic index diet. There are many claims, so I'll try to mention some of the more reasonable (but please note that further research is required to support all of these claims):
In researching low glycemic index diets, it is impossible not to bump into the Atkins diet. This diet recommends cutting out nearly all carbohydrates. Certainly this is one way to achieve a low glycemic index diet, but it is possible to eat a low glycemic index diet without following the Atkins diet. I don't personally feel that cutting a food group such as carbohydrates is healthy or natural. It is possible to eat low glycemic index diet without cutting out carbohydrates altogether. Many people simplify low glycemic index diets to "low-carb" diets, but I disagree. Certainly though, the Atkins diet is the most well studied of the low glycemic index diets and it is impossible to ignore because it has been extremely successful for many people.
Surprisingly, there has been relatively little research done on low glycemic index diets until recently. This is rapidly changing, and more results should start to pour in. Quotes from some recent news on low-glycemic index diets:
| Consumer Reports, June 2002 | ... In one study, Ludwig put a group of overweight children on a standard low-fat diet and a comparison group on a low-glycemic diet. The low-glycemic dieters were instructed to combine protein, healthful fat, and low-glycemic carbohydrates like fruits, vegetables, legumes, and whole grains at each meal. After four months, children on the low-glycemic diet had lost an average of 4.5 pounds, while the kids on the low-fat diet had gained 2.9 pounds... |
| Consumer Reports, June 2002 | ...experiment involving a dozen overweight teenage boys. On one test day, they ate a high-glycemic breakfast and lunch containing lots of easily digested carbohydrates but very little fat and protein. On another day, they ate a low-glycemic breakfast and lunch that contained about twice as much protein and 50 percent more fat, but only two-thirds as much carbohydrates as the high-glycemic meals. The calorie content of both meals was identical. After consuming their test breakfasts and lunches, the boys were allowed to eat as much dinner as they wanted from platters laden with bagels, cold cuts, cream cheese, cookies, and fruit. On the days when they'd previously eaten high-glycemic meals, the boys scarfed down 81 percent more calories at dinner than on the days when they'd eaten the high-protein, low-glycemic meals... |
| Consumer Reports, June 2002 | ...rounded up 42 overweight volunteers. They sent half of them home with instructions to follow the diet in the Atkins book...The second group followed a standard low-fat, low-calorie, high-carbohydrate diet. After 12 weeks, 7 of the original 21 low-fat dieters had quit, while only 2 of the Atkins group had dropped out. Moreover the Atkins dieters had already lost an average of nearly 19 pounds compared with an average loss of just 7.5 pounds for the low-fat dieters... |
| Calgary Herald, Nov. 19, 2002 |
Low-carb diet could keep off the pounds ...But now, some of the same researchers who long scoffed at the diet are putting it to the test, and they say the results astonish them. Rather than making cholesterol soar, as they feared, the diet actually appears to improve it, and volunteers take off more weight. ... At least three formal studies of the Atkins diet have been presented at medical conferences over the past year, and all have reached similar results. ... After six months, the people on the Atkins diet had lost 31 pounds, compared with 20 pounds on the (low fat) diet, and more people stuck with the Atkins regimen. ... Those on the Atkins diet had an 11% increase in HDL, the good cholesterol, and a 49% drop in triglycerides. On the (low fat) diet, HDL was unchanged, and triglycerides dropped 22%. |
| Calgary Herald, Oct. 14, 2003 |
Low-carb meals let you eat more ... The study, directed by Penelope Greene of the Harvard School of Public Health and presented at a meeting here this week of the American Association for the Study of Obesity, found that people eating an extra 300 calories a day on a very low-carb regimen lost just as much during a 12-week study as those on a standard low-fat diet. Over the course of the study, they consumed an extra 25,000 calories. That should have added up to about seven pounds. But for some reason, it did not. |
I've quoted the June Consumer Reports quite extensively above, in fairness, let me add another comment from that article: The number one weight loss suggested by readers who had completed a survey on weight loss (and who had lost weight): exercise. Note that "tame your blood sugar" was the first expert tip listed in the article.
My inspiration for the low glycemic index diet undoubtedly came from reading the book "Sugar Busters!" (Steward, Bethea, Andrews, Balart), but there are now many books out there that promote low glycemic index diets, I recommend you read several and make your own choices based upon knowledge you've gained.
The basic premise of the "Sugar Busters!" book is that some foods raise your blood sugar levels very rapidly. This results in a release of insulin. Insulin stops any fat-burning your body may be doing and starts the conversion of sugar into more fat. Furthermore, insulin inhibits the ability of glucagon to promote fat-burning. Then, insulin usually overshoots the mark, leaving you with a low blood sugar, and hence feeling hungry. As a result you eat more. Their argument is that to lose weight you need to avoid those foods that raise your blood sugar levels rapidly and to eat more foods that promote glucagon (i.e. protein-rich foods). They also claim that their diet can result in lower cholesterol and control diabetes (or even prevent it). I'm not going to go into it other than to say it is an interesting hypothesis that seems plausible. The book basically suggests avoiding these foods that raise your blood sugar levels very rapidly. Furthermore, on my own interpretation of what they said I've started eating more protein (and with every meal). For instance, I eat cheese with breakfast. "The Zone" has formulas to calculate how much protein you should eat every day and I was clearly not getting enough.
Well, essentially anything that man has refined in the past 100 to 200 years is probably bad, but there are a few other surprises like carrots. The argument on corn is that what we eat today is nothing like what the Native Americans grew 100 years ago.
The less refined flour is the better, so whole wheat is better than white, but cracked wheat is better yet. Even so, a lot of cracked wheat bread is mostly made with white flour so I've been avoiding bread altogether for now (just the odd slice). You have to be really careful to watch for sugar in sauces and salad dressings. My wife and I have started using straight mustard rather than a honey/mustard barbeque sauce. Aside from the above exceptions, fruit is mostly encouraged. However, the "Sugar Busters!" book makes the claim that fructose is generally not as bad for you as glucose (makes sense since the body has been dealing with it for 1000's of years), but when combined with other carbohydrates fructose is just as bad as glucose, so they suggest that you eat fruit as a snack, at least one hour before a meal, or several hours after.
Ironically, sweet potatoes aren't so bad: 55 (not great, but better than potatoes). Popcorn at 55 is the best form of corn, but still not great.
Note that different books have slightly varying opinions; the ones below are recommended by the "Sugar Busters!" book.
None of the breakfast cereals score overly well, but Multigrain Cheerio's and Special K are the two recommended by the "Sugar Busters!" book.
I've talked as though low-glycemic index diets are somewhat the opposite of "low fat", that is not entirely true, aside from the Atkins diet, most recommend watching your fat intake, but not as strictly, and certain fats aren't bad (e.g. fish, avocados, olive oil). Low fat diets have been questionable for some time as summarized by Gary Taubes in his article "The Soft Science Of Dietary Fat".
One of the interesting things to note is that when low fat diets were first recommended, the intention was to get people to eat more vegetables (mostly low glycemic index); however, most people (including myself) substituted flour based and other high glycemic index products.
I suggest eating plenty of green vegetables and salads (many studies have shown benefits to Mediterranean style diets), we've found some yogourt based salad dressings that are excellent, but sometimes we even have "high fat" salad dressings (including Caesar), even more Greek salads than usual. We substitute brown and wild rice for white rice. We also keep some whole wheat pasta as it scores acceptably. Pasta in general isn't the worst thing on the list (important to remember when you go out for Italian food - many of the North American Italian restaurants don't serve veal dishes), but I have been finding eating out at Italian and Vietnamese places tougher than before. Oddly though, I can go out for a steak and a salad or for chicken wings. I've been finding fast food more difficult than before, but donairs are a reasonable choice (pita scores okay, tahini and hummus are both good - might explain why I lost weight in Syria/Jordan). Fortunately, there are improved salad choices at fast food restaurants, many of these are great low glycemic index choices.
In addition, as these diets become more popular more businesses are catering to them. More restaurants carry menus catering to either the Atkins' or Sugar Busters diets. As well, there are now low-carb beers on the market, and even a low-carb flour.
Unfortunately, most alcohol has a pretty high glycemic index, most low glycemic index diets recommend small amounts of red wine, or perhaps abstaining from alcohol.
Glycemic index of various foods
Westman study referenced in Herald article
