Now Americans have another excuse for being too fat: It's all that bad information.

For years the government's Food Pyramid Guide has been the nutrition bible. Essentially, the pyramid advises us to load up on pastas and breads, have three servings of meat, fish or poultry, and cut fats, oils and sweets as much as possible.

We've been misled, says Dr. Walter Willett, chairman of the nutrition department at the Harvard School of Public Health, and not just by the Food Guide Pyramid, but by lots of other studies offering us best ways to be healthy.

"People are getting messages from the left and right, often about just the latest findings from a new study, and that's not usually sufficiently reliable," Willett told the Associated Press.

Such misinformation, says Willett, has left most Americans frustrated, confused and woefully overweight. Nearly two-thirds, or 64.5 percent, of adults in the United States are overweight today, compared with 56 percent nine years ago, according to the National Center for Health Statistics. Children and teens ages 6-19 are also fatter. Almost 9 million, or 15 percent are overweight, three times what the proportion was in 1980.

Yet the number of diet products available to consumers have never been more plentiful. In a generation, for example, the sales of diet soft drinks (nearly 30 percent) outpace sugared soft drinks.

Doesn't matter. We're still too fat. And it hits us in the face during the hot months, when swim suit season arrives.

So Willett, meanwhile, is offering another alternative. Instead of loading up on sugar-laden fat-free products, the ideal way to diet is to eat healthy foods that include more plant oils (think flaxseed) instead of animal fats (saturated fats), more whole grains and high-fiber carbohydrates (like brown rice).

He also encourages the eating of oily fish such as salmon, over red meat, taking a daily multivitamin, regular exercise and moderate alcohol consumption.

In other words, the tried and true: Eat less. Exercise more. Lose weight.