Sizing up the South Beach and Portfolio diets

People’s appetite for diet books seems insatiable, and the latest sensation is The South Beach Diet. Written by Dr. Arthur Agatston, a Miami Beach cardiologist, the book is a runaway hit. It was the fourth best-selling book on Amazon.com in the past months and number one on the New York Times list of hardcover advice books.

In many ways, the South Beach plan is similar to the Atkins diet. They’re both low-calorie plans – Atkins, of course, popularized low-carb dieting. Atkins begins with a two-week "induction phase" of strict high-protein, low-carbohydrate eating. The South Beach diet also begins with a very similar two-week "Phase 1" that bans fruit, bread, potatoes, baked goods, sweets, cookies, ice cream, and alcohol. Each has subsequent stages that permit you to add back foods while supposedly maintaining your initial weight loss.

The South Beach Diet says it differs from Atkins by pushing the "right carbs" instead of no carbs. Overall, it is less militant on the subject. But in their initial weight-loss phases, both diets depend on shunning carbohydrates. The South Beach diet does have a more nuance — and correct — position on fats. Although later versions of Atkins’ diet book downplay it, he was famous for lauding meat and dismissing the dangers of saturated fats found in it and other animal-based foods like dairy products. The user-friendly South Beach diet allows meat. But unlike Atkins, it warns against saturated fat and steers people toward fish and chicken.

What’s Wrong With It

In a recent critique of The South Beach Diet, this is what Katherine McManus, director of the nutrition department at the Brigham and Women’s Hospital in Boston and weight loss researcher, has to say:

• Lack of proof. Dr. Agatston says he tested his diet in a randomized study of 40 overweight volunteers and presented the results at a meeting of the American College of Cardiology. That may be true, but one small study conducted by the developer of a diet (hardly an impartial source) is miles away from proof.

• Credibility gap. The book promises that after just two weeks on strict Phase 1, your cravings for sugars and starches will be "virtually gone" and that insulin resistance syndrome will disappear. Insulin resistance syndrome, which probably has a strong genetic component, doesn’t go away that quickly. And it’s hard to believe that appetites for cookies, cakes, and all the other sweets and starchy things people love to eat would change so fast.

• Misleading come-ons. The book says that the diet doesn’t depend on portion sizes. Yet the entire second half consists of meal plans and recipes – which are, in effect, portion sizes. Almonds and cashews are recommended as a snack, but you’re supposed to count out 15, which seems like a portion to us. Early on, we’re told that the diet doesn’t depend on exercise. In a later chapter, Agatston recommends a brisk, 20-minute walk every day. That’s sounder advice. Losing weight through diet alone is possible, but most studies suggest that it’s people who exercise who manage to keep it off.

• An error. The book claims that eggs have no saturated fat, but an egg has about 1.5 grams of saturated fat. Because the long-term "phase 2" part of the diet includes a fair number of eggs, this is a notable mistake.

What’s Right With It

McManus says that she wishes that the book were harder on trans fats. Even so, it does a good job of de-demonizing fat and sorting out the good (mono- and polyunsaturated) from the bad (saturated and trans). Agatston slams processed food and drums in the right message about the benefits of fiber and whole grain foods. It’s debatable whether the connection between obesity and high-glycemic-index carbohydrates (those that rapidly raise blood sugar) is quite as tight as it’s portrayed in the book. But there is growing evidence that high-glycemic foods increase cholesterol levels, in addition to roller coasting your blood sugar and insulin levels. Agatston ably recycles the current wisdom that eggs are not nearly as bad for you as once thought.

Smart Salesmanship

Anyone who has ever dreamed of mass market success could learn from this book. South Beach, of course, is the area of Miami Beach known for its beautiful people — and along comes a diet whose name suggests that this is how they got to be that way. The book is short: The first 107 pages of explanation can be read in one sitting. It’s to the point: The promise that you’ll lose 8 to 13 pounds during the first two weeks is right there on the first page. And it’s tolerant: Agatston says if you slip up and eat desserts, you can redeem yourself by going back to the stricter first phase of the diet.

Last year, several clinical trials show promising weight-loss results from Atkins-like diets. The South Beach diet is not outlandish, and it may work for some. But like any other diet book that has come along, it makes long-term weight loss seem easier than it is. That’s probably why we keep buying them.

The Portfolio Diet

The Portfolio diet, so called because it puts a lot of cholesterol-lowering foods together in one meal plan (like stocks in a portfolio), has also been making news. Three well-designed studies by Canadian researchers supported the benefits of this diet. One study, recently published in the Journal of the American Medical Association, compared this diet with a more conventional cholesterol-lowering, low-fat diet, as well as with a cholesterol-lowering drug. The Portfolio diet, in those studies, worked as well as the drug and much better than the low-fat diet, reducing total cholesterol by about one-third in only a few weeks. The studies were small and short, however, and the researchers called for more studies. So nothing is yet definite. Still, this came as good news for people who know they need to lower their cholesterol levels, but for one reason or another resist taking cholesterol-lowering drugs.

The Portfolio diet is a good one, though limited in the food choices it offers. It is vegetarian: No meats or dairy products are allowed. Thus, it is very low in saturated fat. It is also designed to be high in fiber – especially soluble fiber, the kind that lowers cholesterol. The fiber comes from foods such as soy and other legumes, oats, eggplant, okra, barley, almonds, and cauliflower. Special cholesterol-lowering margarines containing plant sterols (Benecol, for example) are also included. And to really boost the fiber intake, you must consume three daily doses of psyllium, a seed grain sold as a fiber supplement and laxative. Soy foods, such as tofu and/or soy milk, are part of every meal. No sweets are allowed (except fruit jam) and no dairy products. It’s not a starvation diet – you get 2,000 calories a day, and while some people would lose weight on that, many would not. Besides lowering cholesterol, the diet may well offer other health benefits, such as a reduced risk of diabetes.

Pluses And Minuses

So should you try this diet? Your decision should be based on your own circumstances, as well as in consultation with your physician. If your cholesterol level is high, you should try to reduce it through a combination of diet and exercise – and if these don’t work, you should consider medication. If you are a vegetarian, the Portfolio diet may seem easy; if you are accustomed to eating meat, poultry, fish, and dairy, it could be hard. And fish and low-fat or nonfat dairy products have their own cardiovascular benefits.

While low-fat diets help lower total cholesterol, they may also lower HDL ("good") cholesterol. The Portfolio diet apparently does not lower HDL, which is a plus. But it doesn’t raise it, either (no diet raises it significantly). So if you have low HDL – this diet won’t solve the problem. In contrast, some cholesterol-lowering drugs do raise HDL by 10 percent or so. Regular aerobic exercise also boosts HDL. And keep in mind that while cholesterol-lowering drugs have been shown to reduce the risk of a heart attack and death, we don’t actually know if this diet will do so.

Words To The Wise

So, can you stick to a diet consisting chiefly of soy, okra, eggplant, beans, and the like, with three doses of psyllium at every meal? If your answer is yes, this may be the eating plan for you. But if your cholesterol level is high, make this decision after seeking professional advice – and make exercise a part of the program. Psyllium may interact with other drugs: Discuss this with your doctor if you take medications. For more details on the diet, log on to www.portfolio eatingplan.com.