Being a little less carnivorous may help you stay slim, a study in hundreds of thousands of Europeans suggests.

Dr. Anne-Claire Vergnaud of Imperial College London in the UK and her colleagues found that people who ate more meat gained more weight over 5 years than those who ate less meat, but the same amount of calories.

“Our results suggest that a decrease in meat consumption may improve weight management,” they wrote in the American Journal of Clinical Nutrition.

The study included more than 100,000 men and 270,000 women from 10 different European countries participating in a study of cancer and nutrition and other lifestyle factors.

Danes, Germans, Spaniards and Swedes were the biggest meat-eaters, with men eating around 300 calories worth of meat daily and women consuming 200 calories. Among all meat-eating populations, Greeks ate the least (about 200 calories a day for men and 140 for women).

Over the 5-year follow-up period, both men and women gained about a pound a year, on average, although women gained a little less. And the more meat a person ate, the more they gained; for every additional 250 grams of meat a person ate daily (the equivalent of a half-pound, 450-calorie steak), their 5-year weight gain would be 4.4 pounds greater, the researchers calculate.

When the researchers looked at different types of meat separately, they found the strongest association with weight gain for poultry, followed by processed meats and red meat.

Heavy meat-eating could be part of an overall unhealthy diet or unhealthy lifestyle, Vergnaud and her team note.

Because meat is “energy-dense” (meaning it packs more calories by weight than veggies or fruits, for example), it could influence appetite control, they add. However, the researchers did attempt to take overall dietary pattern into account, as well as education, physical activity level, whether or not people smoked, and their total calorie intake.

Based on the findings, a person who cut their meat consumption by 250 grams daily (about a half-pound) could conceivably reduce their 5-year weight gain by around 4 pounds.

While this is a relatively small amount of weight from an individual’s point of view, the researchers add, gaining an average of 4 pounds in 5 years “could have an important effect from a population perspective.”

“More importantly,” they add, “our results do not support that a high-protein diet prevents obesity or promotes long-term weight loss, contrary to what has been advocated.”

SOURCE:  American Journal of Clinical Nutrition, online June 30, 2010.