Andrew Weil, M.D., states in his book The Healthy Kitchen, "What is undermining our health is processed foods. They are the main source of bad fats and bad carbohydrates, along with the additives we don't need, and they displace from our diets the fruits, vegetables and whole grains we do need for the protective elements they contain."

One can lose weight on any kind of diet, but keeping it off is quite another matter. More than a decade ago, a panel of experts from the National Nutrition Coordinating Committee concluded that none of the conventional approaches to losing weight is effective—in other words, most diets don't work. In fact, the panel concluded, "Evidence suggests that weight-loss regimes do more harm than good." Within a year most people have regained at least two-thirds of the loss, and only 3 percent keep the weight off for at least five years.

This pattern is familiar to anyone who has tried dieting. The key to success is not a time-limited dieting regimen to lose weight, but the establishment of a lifelong mode of healthy eating habits that one can live with.

Most people find a low-carbohydrate regimen easier and more satisfying than a low-fat one, says Weil, and medical research strongly supports the idea that many people are carbohydrate-sensitive as a result of their genetic makeup. These people gain weight easily on products made of flour or sugar. But the Atkins diet is overloaded with meat and deficient in fruits and vegetables; using the Atkins diet is not recommended by Weil for longer than six weeks. The tilt toward meat with a deficiency in fruits and vegetables in the Atkins diet puts too much of a workload on the kidneys and undermines the defenses against cancer and other chronic diseases that tend to show up later in life.

Weil's concern about the Atkins diet seems to be supported by other nutritional experts. For example, Neil Barnard, M.D., in his book Foods That Fight Pain, warns of the loss of calcium from the bones due to too much animal protein. "Plant protein does not appear to have this effect," he states. Weil agrees that a plant-based diet is the best, but also warns that vegetarians and vegans have a tendency to fall into the trap of too many carbohydrates with accompanying deficiencies of key micronutrients. One of those micronutrients is B-12, found only in animal foods. Most multivitamin/mineral supplements include six micrograms of B-12, which is 100 percent of the minimum requirement.

Weil recommends a sensible low-carbohydrate diet with vegetable protein (from soy and other legumes) and plenty of other vegetables. The diet should also include some fruit (especially berries), fats (like olive oil, nuts, avocado, oily fish), some slowly digested carbohydrate foods (like beans, sweet potatoes, winter squash) and whole grains (like wild rice and quinoa), which, along with the fruits and vegetables, provide needed fiber.

The problem with fast food, according to Weil, is the use of too much fat and the wrong kind of fat (saturated, polyunsaturated, partially hydrogenated); too much carbohydrate and the wrong kind of carbohydrate (white bread, French fries, chips, sugary drinks); too much animal protein; too little good carbohydrate (whole grains, fruit, beans); and an almost complete lack of the protective elements found in fruits and vegetables. It's a tough job to eat well in this environment, but one nutritionist decided to help seniors make the right choices.

Kim Verity from De Anza College teaches a course in health and nutrition for seniors. In a recent class at the Cupertino Senior Center, she produced a handout entitled Healthy Fast Food? that took a close look at the contents of food from several of our most popular fast-food establishments. The news was mostly bad, but Verity was able to identify some low-calorie offerings that busy folks, and those on vacation or traveling, can eat and still protect their waistlines.

Verity's rules to avoid the worst of the fat traps include:

1. Avoid breakfast items—fried eggs, bacon, melted cheese and special sauces are loaded with cholesterol, fat and sodium. Note that a few of us are salt-sensitive, which increases blood pressure and the workload on the heart; African Americans and people with family histories of hypertension are likely to be in this group.

2. Avoid anything fried or "crispy"—these items are usually fried in hydrogenated oil.

3. Don't eat chips or nachos (150­300 calories).

4. Skip the tortilla or "wrap" (300 calories) and the tortilla shell of your taco salad or tostada (500 calories).

5. Don't buy the bigger, better or super-sized meals: you get a lot of calories for the extra money!

It's always smart to eat at places that will share nutritional information about their food. As always and forever, calories count.