But adding some dairy products and a limited amount of meat may actually increase this efficiency, Cornell researchers suggest.

This deduction stems from the findings of their new study, which concludes that if everyone in New York state followed a low-fat vegetarian diet, the state could directly support almost 50% more people, or about 32% of its population, agriculturally. With today's high-meat, high-dairy diet, the state is able to support directly only 22% of its population, say the researchers.

The study, published in the journal Renewable Agriculture and Food Systems, is the first to examine the land requirements of complete diets. The researchers compared 42 diets with the same number of calories and a core of grains, fruits, vegetables and dairy products (using only foods that can be produced in New York state), but with varying amounts of meat (from none to 13.4 ounces daily) and fat (from 20 to 45% of calories) to determine each diet's "agricultural land footprint."

They found a fivefold difference between the two extremes.

"A person following a low-fat vegetarian diet, for example, will need less than half (0.44) an acre per person per year to produce their food," said Christian Peters, M.S. '02, Ph.D. '07, a Cornell postdoctoral associate in crop and soil sciences and lead author of the research. "A high-fat diet with a lot of meat, on the other hand, needs 2.11 acres."

"Surprisingly, however, a vegetarian diet is not necessarily the most efficient in terms of land use," said Peters.

The reason is that fruits, vegetables and grains must be grown on high-quality cropland, he explained. Meat and dairy products from ruminant animals are supported by lower quality, but more widely available, land that can support pasture and hay. A large pool of such land is available in New York state because for sustainable use, most farmland requires a crop rotation with such perennial crops as pasture and hay.

Thus, although vegetarian diets in New York state may require less land per person, they use more high-valued land. "It appears that while meat increases land-use requirements, diets including modest amounts of meat can feed more people than some higher fat vegetarian diets," said Peters.

"The key to conserving land and other resources with our diets is to limit the amount of meat we eat and for farmers to rely more on grazing and forages to feed their livestock," said Jennifer Wilkins, senior extension associate in nutritional sciences who specializes in the connection between local food systems and health and co-authored the study with Gary Fick, Cornell professor of crop and soil sciences. "Consumers need to be aware that foods differ not only in their nutrient content but in the amount of resources required to produce, process, package and transport them."

According to the U.S. Department of Agriculture, the average American ate approximately 5.8 ounces of meat and eggs a day in 2005.

"In order to reach the efficiency in land use of moderate-fat, vegetarian diets, our study suggests that New Yorkers would need to limit their annual meat and egg intake to about 2 cooked ounces a day," Peters said.

The research was supported in part by the National Research Initiative of the USDA Cooperative State Research, Education and Extension Service.

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Our data showed those people in the high-glycemic-index group were at greater risk of AMD progression, especially those already in the late stages, says first author Chung-Jung Chiu, DDS, PhD, scientist in the Laboratory for Nutrition and Vision Research at the USDA HNRCA and assistant professor at Tufts University School of Medicine. Participants who consumed the most refined carbohydrates were 17 percent more likely to develop blinding AMD than the group that consumed the least.

According to the authors, public health officials believe the condition could spur a public health crisis in the United States by 2020, when they predict the cases of AMD-related vision loss will have doubled to three million.

No one has been able to identify an effective noninvasive intervention that will slow the progression of AMD says Taylor, who is also a professor at the Friedman School of Nutrition Science and Policy at Tufts and Tufts University School of Medicine. We feel we have identified a risk factor that could postpone the debilitating loss of vision with very little economic or personal hardship. Based on our data, limiting refined carbohydrate intake, such as by limiting sweetened drinks or exchanging white bread for whole wheat, in at-risk elderly could reduce the number of advanced AMD cases by 8 percent in five years. This can equate to saving the sight of approximately 100,000 people.

The authors note that their findings warrant randomized controlled clinical trials.

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