Modern man is basically living in a prehistoric body, according to some researchers. Our genetic makeup has changed very little from the days when our hunter-gatherer ancestors ate a diet of wild plants and animals, a diet referred to as the Paleo diet (short for Paleolithic diet) or caveman diet. Grains weren't introduced as a major part of the human diet until man settled down to farm about 10,000 years ago, says Loren Cordain, author of "The Paleo Diet: Lose Weight and Get Healthy by Eating the Food You Were Designed to Eat."

The processed, refined foods with high amounts of carbohydrates in today's diets didn't even exist until about 200 years ago, a mere blink in evolutionary time, and our 21st century eating habits are killing us.

Cordain, a professor at Colorado State University, believes that our diet filled with processed and artificial foods has played havoc with our health and is responsible for the dreaded diseases of modern man, which include heart disease, cancer, diabetes, and obesity. For instance, he believes that prehistoric man's balance of omega-3 and omega-6 fats would have prevented cardiovascular problems, and that modern man gorging on starchy carbs has created mayhem with our glucose levels.

Our ancestors were "lean, fit, and free from heart disease and other ailments that plague Western countries," said Cordain in the Washington Post. Then he added. "Look at us. We're a mess. We eat too much, we eat the wrong foods, and we're fat."

Many foods most people eat every day are forbidden or restricted on the Paleo diet because they were not available to our distant ancestors. Exercise is discouraged for the first two weeks of the diet.

Foods encouraged by the Paleo diet include:

• Organ meats
• Game meat
• Fish
• Shellfish
• Fruit
• Vegetables
• Nuts and seeds

Foods discouraged by the Paleo diet include:

• Dairy foods
• Cereal grains
• Legumes (beans, lentils and soybeans)
• Starchy vegetables (potatoes and yams)
• All foods containing salt
• Fatty meats
• Soft drinks
• Sweets

Foods allowed in moderation include oils, coffee, tea, beer, and wine.

The Times Online offers these tips for modern cavemen:

• Eat more wild greens.
• Forage for wild mushrooms.
• Do not overcook food.
• Opt for fish and game whenever possible.

The Paleo diet has its detractors, most saying that the hunter-gatherer lifespan was short, and they didn't have time to develop many of the diseases that plague modern man. Cordain refutes this by saying that as many as 20 percent of hunter-gatherers lived to be 60 or older and although they had no modern medicine, they were free of the chronic medical conditions associated with aging in today's society.