Do or diet: The new weight loss plans

The titles of the newer diet best-sellers vary, but their promises are strikingly similar. Eat “lots and lots of great food in smart ways,” says The Abs Diet. “Lose weight by enjoying satisfying amounts of the best food on the planet,” promises The Sonoma Diet. And The Best Life Diet lets you “live happily on the diet while still meeting your weight-loss goals.”

Living happily on a diet plan seems to fly in the face of most people’s experience. In a 2006 Pew Research Center survey, more than 90 percent of 2,250 adults said losing weight was “hard” or “very hard.” So the latest popular diets focus on how to shed calories and pounds in a way that keeps you from feeling hungry. In contrast with earlier diets, which tended to severely restrict major nutrient categories — carbohydrates in the case of the Atkins Diet, fat in the case of Ornish, Pritikin, and many other diets — this latest generation of diets recognizes that fat and carbs represent more than expendable calories. They fill you up, add flavor and variety, and impart important health benefits, if you choose wisely.

While the diets quibble over details, the nutrition they recommend is largely the same — a balanced diet focused on fruits and vegetables that includes “good” proteins, grains, and fats. Here’s a look at the new diet consensus:

• Complex carbs. Low-carb eating strategies became popular because people found they could lose weight without feeling as hungry. For example, a year-long study of more than 300 overweight, premenopausal women published in the March 7, 2007 issue of the Journal of the American Medical Association found that Atkins dieters lost more weight than those assigned to moderate- or high-carb eating plans. Research shows that unlike low-fat plans, low-carb diets do not decrease LDL (bad) cholesterol, but some experts worry that over the long term, a strict low-carb menu may compromise health by being too high in protein and fat and too low in fruits and whole grains.

Newer eating strategies eliminate only the highly-refined carbs — white bread, cookies, chips, soft drinks — that can be a major source of excess calories. But they keep the nutritious, fiber-rich carbs, which, like protein and fat, are digested slowly and don’t cause the blood-sugar spikes and subsequent hunger that simple carbohydrates can.

These meal plans tend to be low on the glycemic index, a measure of the impact of the food on blood sugar. Research shows that a low-glycemic approach can help improve blood sugar control and lower LDL and total cholesterol, all factors that help reduce the risk of diabetes and cardiovascular disease.

While some diets, such as The New Glucose Revolution, focus strictly on the glycemic index, calculations for meals can be complex. For example, the glycemic load of a banana is tempered when you add whole grain cereal and milk. And there’s no evidence that eliminating nutritious produce with a high glycemic index, such as watermelons, carrots, and beets, will help you lose weight faster or keep you healthier in the long run.

• Healthy fats. In practice, very low-fat diets can be hard to maintain. Furthermore, the American Heart Association does not recommend a very low-fat, high-carbohydrate approach because it can raise triglycerides and provide excessive amounts of fiber, which can interfere with the absorption of some nutrients such as calcium, iron, and zinc.

Fats are filling and flavorful, and if you choose poly and monounsaturated fats from plant sources, such as olive oil and nuts, they can have health benefits. Although all fats are high in calories, newer generation menus incorporate them nonetheless, based on the premise that you will be more satisfied with less food. The Mediterranean theme common with many popular diets stems from the theory that the healthy fats in this region’s diets contribute to their lower incidence of heart disease. Recent research supports this idea. A clinical trial of 772 middle-aged and older adults at high risk for heart disease, published in the July 4, 2006 issue of the Annals of Internal Medicine, found that people who increased their consumption of olive oil or nuts for three months lowered their blood pressure, cholesterol, and blood sugar levels more than those assigned to a low-fat diet. A little fat goes a long way, however, and dieters especially should not overdo it. One-quarter cup of almonds, for example, will add roughly 200 calories to your daily total.

• Protein from fish and legumes. Recipes in newer diet books stress lean sources of protein because they contain little if any saturated fat and cholesterol, but fill you up and provide plenty of nutrients for your calorie buck. The American Heart Association recommends eating fish — particularly fatty fish such as lake trout, white fish, and wild salmon — at least twice a week because the omega-3 fatty acids in these fishes can reduce the risk of heart disease. Legumes (beans, lentils, peas, and peanuts) are also nutrient-rich and provide plentiful fiber.

And Now, For The Details

While agreeing on the big picture, some popular diet books are quite prescriptive about specific, sometimes quirky, rules.

• Bad and good food items. Sugar Busters declares that “potatoes are for pigs and corn is for cattle!” The best-selling YOU on a Diet recommends baked potatoes and popcorn for snacks. The Sonoma Diet instructs readers to eat 10 “diet power foods,” including strawberries, tomatoes, and spinach.

Studies do, indeed, suggest that certain food classes — such as fatty fish, whole grains, dark leafy greens, the broccoli-cauliflower cruciferous family, nuts, certain red or orange produce, and berries — may help reduce your risk of disease when integrated into a balanced diet. But barring dangerous food allergies, no single food can by itself make or break a diet, and that approach can even be detrimental if adherence is so difficult that you give up on the diet completely.

• The strict starter menu. Many plans start with a restrictive phase that lasts a few weeks, then give way to a longer period that allows slightly more calories and a greater variety of foods. Research suggests that there may be a benefit to jump-starting your weight loss through early restrictions, though you needn’t go as far as the plan in French Women Don’t Get Fat and start by eating only leek soup for two days. Studies show that dieters who lose more weight in the first three to six months are more likely to maintain those losses than those who get off to a slower start. However, any very restrictive diet phase should be temporary to minimize any risk to your health. Your ultimate goal is to find a long-term strategy that is practical.

• Exotic supplements. There’s no evidence that you need to supplement your diet with powdered whey protein (as The Abs Diet instructs) or a medicine full of vitamins, minerals, and herbs (Ultrametabolism recommends a long list). Several supplements do make sense, however. People who are restricting calories should cover their nutritional bases with a multivitamin, and those who do not eat the recommended three daily servings of dairy (or calcium-rich foods) should consider a calcium supplement. Extra vitamin D is a good idea for people who are rarely in the sun and do not consume vitamin D-rich foods.

Finding Your Best Diet

Does this latest round of diets mean that low-carb or low-fat devotees need to change their strategy? Not necessarily. Achieving a healthy weight has a more profound effect on reducing disease risk than the diet you use to get there, the research shows.

Truth is, just about any diet will work — as long as you stick to it. In a January 5, 2005 study published in the Journal of the American Medical Association, Tufts University nutrition researchers compared four very different diets — Atkins, Ornish, Weight Watchers, and the Zone — in 160 overweight individuals. Although the overall adherence rate was low, those who managed to stick it out for a year lost a modest amount of weight, regardless of the eating plan.

In fact, in one survey involving 32,000 dieters, it was found that most of those who successfully lost weight and kept it off did so without following a specific plan. Instead, they just used sensible strategies such as cutting portion size and staying away from sweets and junk food.

The bottom line is this: The only thing that works for weight loss is cutting calories. And there’s a lot of variety in how to do it!