The G.I. Diet: The Easy, Healthy Way To Permanent Weight Loss

Introduction

While I was president of the Heart and Stroke Foundation of Ontario for fifteen years, my job was to raise funds for research into heart disease and stroke and to promote healthy lifestyle choices among Canadians to reduce their risk for those diseases. The Foundation has developed the most comprehensive set of heart disease, stroke and healthy lifestyle resources in Canada. We now know that smoking, high blood pressure, high blood cholesterol, a sedentary lifestyle and being overweight are all major risk factors for heart attacks and strokes. So a few years ago, when I was twenty pounds overweight, I knew I had to reduce. And with all the information and resources I had, I thought I knew how: I went out and bought a Nordic ski machine and a stationary bike, and I started working out every day. But however hard I exercised, I found I could only stabilize, not lose, the weight. For the first time in my life, I realized I had to go on a diet.

Conventional nutritional wisdom at the time recommended a low-fat, high-carbohydrate diet. All I had to do was stop eating fatty foods like cheese and ice cream, and start eating more low-fat carbohydrates like pasta, rice and vegetables — right? Wrong. Though I stuck diligently to the diet, eating pasta and tomato sauce instead of steak and Caesar salad, I wasn’t losing any weight at all. In frustration, I turned to the filing cabinets at the Heart and Stroke Foundation of Ontario. The Foundation receives literally hundreds of diet books, products and recipes every year, all hoping for support or endorsement. Looking through the files, I quickly ruled out food-specific diets, such as the grapefruit or banana diet, because they have no scientific basis, are risky to your health, and are impossible to sustain over the long term.

I also decided to avoid high-protein diets since various studies had found them to be a real health hazard. High-protein diets, which drastically limit the amount of carbohydrates you consume, put the body in a state of ketosis. As the body is starved of carbohydrates, your principal source of energy, it starts breaking down protein, including the body’s own lean muscle, for energy, which releases a lot of water weight. This creates toxic by-products called ketones, which are removed from the body through the kidneys and can cause an array of problems, from mild nuisances like bad breath to toxic side effects such as kidney damage, diarrhea, dizziness and kidney stones. And because so much protein blocks calcium absorption, people who follow high-protein diets develop bone weakness too. To complete this tale of woe, when you go off the diet, the water weight loss is quickly replaced, and unless you are into a heavy exercise regimen, the weight you gain back will all be fat; the muscle loss will not be recovered.

So, diets based on a single food, and high-protein diets were out. I was still left with a whole host of diets to try, and I selected one that appeared to be based on sound nutritional principles. After several unsuccessful months with that one, I embarked on another, and then a few months later, another. In the end I tried I don’t know how many of them. I counted calories. I studied labels — a real challenge with Canadian labelling regulations (or lack thereof). I starved. I hallucinated about food. Sometimes I did lose a few pounds, but then I’d hit the inevitable plateau, unable to go any further. And since I was constantly hungry, I’d soon start eating what I wanted and gain back the few pounds I’d managed to lose.

It seemed like I was destined to spend the rest of my life overweight. It was the most discouraging thing I have ever experienced. I couldn’t understand why losing weight was so difficult, and I felt there had to be a way to slim down and maintain a healthy weight without having to feel hungry every moment of the day, jeopardizing one’s health or requiring a Ph.D. in math to calculate various formulas and ratios. I was determined to find a diet that would work, not only for myself but also for others in the same boat — gaining weight and increasing their risk for heart disease and stroke, not to mention diabetes.

My quest eventually led me to one of the nutritional researchers supported by the Heart and Stroke Foundation of Ontario. He introduced me to the G.I., or Glycemic Index, through a book called The Zone by Dr. Barry Sears. The Zone diet is based on the principles of the G.I., which measures the speed at which your body breaks down carbohydrates and converts them to glucose, the vehicle your body uses for energy. The faster the food breaks down, the higher the rating on the index. When trying to lose weight it is critical to avoid foods that have a high G.I. and to eat low-G.I. foods instead. The glycemic index was invented by Dr. David Jenkins, a professor of nutrition at the University of Toronto. Since he was living in my hometown, I decided to pay him a visit.

A lean Englishman who clearly practises what he preaches, Dr. Jenkins explained that early in his research career he became interested in diabetes, a disease that hampers the body’s ability to process carbohydrates and sugar (glucose). Sugar therefore stays in the bloodstream instead of going into the cells, resulting in hypoglycemia and potentially coma. At the time Dr. Jenkins was beginning his research, carbohydrates were severely restricted in a diabetic’s diet as they quickly boost the sugar level in the bloodstream. But because the primary role of carbohydrates is to provide the body with energy, diabetics were having to make up the lack of calories through a high-fat diet, which does not boost sugar levels. As a result, many diabetics were increasingly at risk of dying from heart disease, since fat is a critical factor in the development of that disease. Doctors were in a real quandary: although they were saving diabetics from starvation, they were accelerating their risk of heart disease.

Dr. Jenkins wondered if all carbohydrates are the same. Are some digested more quickly and as a result raise blood sugar levels faster than others? And are others “slow-release,” resulting in only a marginal increase in blood sugar? The answer, Jenkins discovered, is yes. He published an index — the glycemic index — in 1980, showing the various rates at which carbohydrates break down and release glucose into the bloodstream.

I decided to try The Zone. To my amazement and delight I lost the twenty pounds that had been plaguing me for so long. I invited some of my friends and associates to try it as well. By the end of twelve months, however, 95 percent had dropped out. They cited two principal reasons for their inability to stick to the diet: 1) it was too complex for everyday life, requiring them to count grams and calculate formulas and ratios; and 2) they were always feeling hungry, which is the death knell for any diet.

The 5 percent who managed to hang in were so happy with their success that I received numerous e-mails from them describing how important their weight control was in their lives. Here are a few of their comments:

Overall, I have lost twenty-two pounds. And I feel more energized . . . I don’t even notice that I’m eating differently. I certainly don’t feel like I’m on a diet; I just feel like I eat in a new way.

Well, with Thanksgiving, two large family dinners, weekend guests, lunches with friends, being on the road and my love of wine and food, I have managed to lose fifteen pounds. I can honestly say my energy is better — I’m not falling asleep in front of the TV any more.

This weekend, my son returns home from university to attend his commencement ceremonies at his high school. After fourteen years, I will be wearing the same skirt I wore when I dropped him off for his first day of school in Grade 1.

Dismayed by the 95 percent dropout rate but bolstered by the successful 5 percent, I set out to address the two key impediments to success: complexity and hunger. The result is this book. The G.I. Diet is simple to follow and will not leave you feeling hungry. The plan comprises a unique combination of foods that have two essential characteristics: they make you feel full for a longer time, so you are naturally inclined to eat less, and they are low-calorie. If you, like me, have been reading other recent diet books, you will have noticed that the word calorie is never used. But lowering caloric intake is the only route to weight loss, and all those diets are, in fact, low-calorie; it’s just that the word has been omitted. With the G.I. Diet, you won’t need to count calories, or weigh or measure your food. I’ve done all the math for you to create the easiest eating plan possible, one that reflects the demands of the busy world we live in. While most diet books take three hundred pages or more to make their point, The G.I. Diet is simple and concise, with very little scientific jargon. Its most important feature is that it works. You’ll find it so simple to follow, so effective, you’ll never have to pick up a diet book again.