by Sally Grande 

Many vegetarians have been led to believe that consuming an unlimited quantity of high carbohydrate foods is perfectly healthy. Some people eat what they like and remain slim and vigorous after decades of unchanged eating habits while others wonder why, as vegetarians, they seem to experience weight gain and fatigue.

Barry Sears, author of the best seller, Enter The Zone, (Regan Books, 1995) thinks he knows. At first glance, vegetarians might think that the Zone diet is a reincarnation of other high-protein, non-vegetarian diets (Scarsdale and Atkins) which were popular in the 1970s. While Sears stresses protein (the book's title refers to the high protein zone), he is not anti-vegetarian but readers of his book may be influenced to cut carbohydrates and gorge on high protein foods.

I came across Sears' book and echoed the same sentiments that appeared in the January 1997 issue of Vegetarian Times, where Karen Cope Straus, Food Editor, offers a positive summary to vegetarian readers who might be contemplating Sears' pro-protein stance. Sears, like other protein-diet advocates, blames obesity on carbohydrate intake, which he claims causes insulin resistance.

Carbohydrates come in different shapes and sizes but all are starches. Some starches are simple, like the potato, but as a simple starch, it transforms directly into sugar in the blood stream and can cause problems for diabetics just like candy would. In a diet full of breads, pastas, potatoes and rice, there is actually a lot of sugar flooding into the bloostream contributing to a condition called "insulin resistance". According to Sears, when a high-carbohydrate meal or sugary beverage (alcohol included) is consumed, an exaggerated insulin response occurs that prevents the proper processing of the glucose so that it remains in the bloodstream and the insulin levels remain low. This condition causes the body to store more fat and prevents the release of previously stored fat. The glucose remains in the liver instead of feeding the brain. People who have this insulin response to high-carbohydrate meals are said to be predisposed to obesity and other serious health risks.

Sears claims that 25% of the population is not insulin resistant and can tolerate high levels of carbohydrates with no weight gain and no adverse health effects. He claims that another 25% is resistant, as in the case of those with diabetes. The remaining 50% fall somewhere between the two extremes. Heredity determines the level of insulin resistance in each person. Sears claims that the key to an optimal metabolism is more judicious use of carbohydrates. However, most low carbohydrate diets are also low calorie diets and it is no surprise that people lose weight when they reduce their calorie intake.

Particularly annoying for vegetarian readers is Sears' attack on the work of vegetarian physicians, particularly Dean Ornish. Sears recounts that patients on the Ornish heart disease reversal program experience a dramatic drop in cholesterol levels within weeks of being vegetarian but their triglyceride levels jump up and that sounds ominous, says Sears. What Sears doesn't add, according to vegetarian physician Mark Fromberg in British Columbia, is that these tryglicerides drop after a short time as well. Toronto Vegetarian Association has its share of members following the Ornish program and they can testify to its longterm benefits. While Sears' assumptions may be faulty, he does pose a valid question: Is there an optimal balance of low-carbohydrate/high protein foods versus low-protein/high carbohydrate foods in the diet? 

Listening to your body and monitoring the effects of dietary change are part of a healthful lifestyle

Although The Zone is not a weight-loss program, it may help explain why some vegetarians can eat liberally in all the food groups and remain slim, while other vegetarians who eat only low-fat foods seem to fight the battle of the bulge constantly. Certainly the factors contributing to a balanced metabolism are complex, exercise being one of the principle components. Anyone who starts to substitute more fresh fruits and vegetables for high-fat foods, will lose weight and reduce their risk of contracting a diet-related disease. However, for certain people, after 10 or 20 years on a diet which encourages regular intake of pasta, rice and other carbohydrates, their bodies may benefit from a different approach. Perhaps a shift to more concentrated vegetarian protein foods (tempeh, TVP and tofu) and higher doses of low-carbohydrate vegetables such as broccoli or cabbage (and almost anything green) is enough to make a difference?

We should remember that plant sugars, like cellulose, pectin, fructose and gums, are beneficial because they encourage the growth of good bacteria in the gut and provide a sticky surface on which cholesterol and other toxins are carried out of the body.

The hard part for vegetarians trying the Zone diet is eliminating most beans, nuts and nut butters, bread, bagels, muffins, potatoes and rice, limiting some fruits such as bananas, some juices and even some vegetables such as carrots. The Zone can be more easily adapted to lacto-ovo vegetarians who can use fat- and cholesterol-reduced dairy products in addition to tofu and TVP.

Sears also recommends dropping caffeine and limiting alcohol since both have dramatic consequences for insulin levels. That's about all he would have in common with John McDougall MD, a vegetarian advocate of rice and other complex carbohydrates as staples.

The emphasis on low carbohydrate foods also aligns with the recent research into ancient diets, which likely consisted of very few cooked or baked foods, little in the way of complex grains and no processed foods. Before the domestication of animals and horticulture, it is very likely that the human diet consisted of large quantities of low-carbohydrate plant materials such as leafy greens, root vegetables, some seeds, berries and small amounts of high protein items such as nuts, the occasional egg, insects or the results of a rare and risky hunt. In this scenario there is little room for excess protein but lots of room for exercise, sunlight and fresh air.

Looking back and looking forward, there are no easy answers. One thing is for sure though, increasing the quantity of green, leafy vegetables in the diet almost always has positive consequences. Listening to your body and monitoring the effects of a dietary change, especially going vegetarian, is part of maintaining a healthful lifestyle. Toronto Vegetarian Association is here to help everyone do just that!

From the March/April 1997 isssue of Lifelines