Meat Is Murder: America's Deadly Beef Obsession

For most Americans, a meal isn't a meal unless there's a piece of meat on the plate. But the desire to have chicken or beef every time we sit down to eat is making us sick -- not only by increasing our waistlines, but raising our risk for cancer and heart disease as well.

The average American ate more than 57 pounds of beef and 45 pounds of pork in 2012, according to the American Meat Institute, a national trade organization. This works out to more than a half-pound of meat-based protein per day, which doesn't include protein from non-meat sources. "Americans are eating 57 pounds more meat than they were in 1950s," says Dean Ornish, a clinical professor of medicine at the University of California-San Francisco and founder of the Preventive Medicine Research Institute. "It's not surprising why Americans are fatter than ever."

[See U.S. News Best Diets: The Ornish Diet.]

Much of the disease risk comes not just from red meat, but from processed meat, such as hot dogs, bacon and lunch meats, which contain nitrates, says Jennifer Weddig, a registered dietitian and associate professor of nutrition at the Metropolitan State University of Denver. "Those meats have been shown to increase your risk of death from all causes, especially cancer and heart disease," Weddig says. "No one would argue that."

Red meat has recently been linked to poor health outcomes as well, Weddig says. A 2012 study in the Archives of Internal Medicine looked at more than 121,000 doctors and nurses and found that those who ate one 3-ounce serving of red meat per day were 13 percent more likely to die of cardiovascular disease or cancer -- and that number jumped to 20 percent for those ate processed meat more than once per day. "The studies are clear in their link," Weddig says. "People who eat large amounts of red meat have an increased risk of mortality."

[Read: How Often Should You Eat Red Meat?]

Red meat is full of saturated fat that raises your risk for these conditions, Ornish says, but there is more danger than just potentially clogging your arteries. "Meat protein also causes inflammation throughout the body, which can also contribute to your risk for disease," he says.

Hard-core carnivores also up their disease risk by living a generally unhealthy lifestyle, Weddig says. "People who eat a lot of meat tend to have a diet low in fruit and vegetable consumption," she says. "They also tend to report not exercising regularly or smoking, which raises their risk for heart disease and cancer even further."

Despite what some studies and dietitians say, the meat industry insists its product is not only safe, but healthy as well. "Meat, whether fresh or processed, is an excellent source of protein, iron, minerals and many vitamins," says Betsy Booren, vice president of scientific affairs for the American Meat Institute. "A substantial body of evidence shows protein can help in maintaining a healthy weight, building muscle and fueling physical activity -- all of which play an important role in a healthful lifestyle and disease prevention."

[See: Me, Give Up Meat? Vegan Diets Surging in Popularity.]

And she's not wrong. Protein is a necessary component for living a healthy lifestyle -- but that protein doesn't always have to come from meat. In fact, that the United States Department of Agriculture recommends getting 5 to 6 ounces of protein from a variety of sources daily. While switching from red meat to chicken or fish is a good start, Weddig says, a more meaningful change would be to get more of your daily protein from non-meat sources, such as nuts or eggs. "Choosing non-meat sources for protein two days a week can make a big difference," she explains. "You'd see a reduced risk of cancer and cardiovascular disease very quickly."

That's not to say that meat is unsafe or everyone should go vegetarian. Instead, start by making a change in what type of meat you eat, which many Americans are already doing -- since the 1970s, poultry consumption has increased by 107 percent. "Eating white meat chicken and fish does not confer the same risk for cardiovascular disease or cancer that red meat does," Weddig says.

[Read: Healthy Red-Meat Substitutes You'll Love.]

And while you're making a change, get rid of other unhealthy dietary habits as well, Weddig says. "I'm not trying to villainize meat," she says. "Red meat does cause health problems, but there is more to it. A diet high in carbs, sugar and a lack of exercise is also to blame, and can play just as big of a role as meat does."

Which is why when you replace some of the meat in your diet with fruits and vegetables, you're actually getting double the benefit, says Ornish, who founded the popular Ornish diet, which focuses on plants and whole foods. "Not only are you reducing your intake of disease-causing substances, but you're also increasing your intake of beneficial substances," he says. "There are literally hundreds of thousands of these substances in fruits and vegetables that help protect against cancer and slow the aging process."

[See: 7 Reasons to Choose a Plant-Based Diet.]

And the best part, Ornish says, is that the more you substitute healthier protein options, fruits and vegetables into your diet, the better off you'll be. "It's not all or nothing," he says. "The more you change, the more you improve your health."

Amir Khan is a Health + Wellness reporter at U.S. News. You can follow him on Twitter, connect with him on LinkedIn or email him at akhan@usnews.com.