A new, comprehensive study of diets gives the green light to meat consumption – that’s the good news. But Dr. Donald Layman says the study does not constitute blanket permission to consume 16-oz. steaks every night. "No way," he told MEATPOULTRY.com.
The study, carried out by a joint team from the University of Illinois and Pennsylvania State University and which appears in this month’s peer-review Journal of Nutrition, sought to compare a diet of moderate protein consumption (40 percent carbohydrates, 30 percent protein, 30 percent fat), which was consumed for four months of active weight loss and eight months of weight maintenance, by 65 subjects, with a diet based on USDA’s food pyramid recommendations (55 percent carbohydrates, 15 percent protein, 15 percent fat), also consumed by 65 subjects according to the four-and-eight regimen. The results: total weight loss in individuals in the two groups was similar, but the moderate-protein subjects lost 22 percent more body fat than the other group, and at the 12-month stage had lost 38 percent more body fat. Overall, the moderate-protein group lost 23 percent more weight than did the food-pyramid group. Measuring lipids, the study found that the food-pyramid diet appeared to be more effective in the short term for lowering LDL blood lipids and total cholesterol, but in the long-term the diets produced the same results.
"There were really no good long-term studies on moderate-protein diets," said Dr. Layman, who is an emeritus professor of nutrition at the U of I. "It’s important to remember that there’s a big difference in the efficacy of a diet and the effect of a diet. This is the best long-term study, I think. We actually tested the effect of diet and found that a moderate-protein diet can have a significant positive effect on body composition as well as on cardio-vascular disease risk factors such as cholesterol."
In a statement announcing publication of the study, Dr. Layman said: "The additional protein helped dieters preserve muscle. That’s important for long-term weight loss because muscle burns calories -- if you lose muscle, and you used to be able to consume 2,000 calories without gaining weight, you’ll find that now you can only eat, say, 1,800 calories without weight gain."
"Moderate" in Layman’s recommendation means 50 grams, or about six ounces, of lean meat three times a day. "We should eat more protein at breakfast," he told MEATPOULTRY.com, but, alas, that does not mean more bacon. "A little bacon every once in a while is fine, but for regular breakfast meat it’s just too fatty. Ham is better." He added that skipping breakfast and lunch protein does not mean you can load up all at once at dinner with a giant slab of meat. "Spreading it out across the day seems to be important," he said.
None of the study’s 130 subjects took prescription cholesterol-lowering medicine such as Lipitor, and exercise was monitored closely with pedometers and activity logs. But exercise was not required, Layman noted: "We had people who ran daily and others who were totally sedentary."
In the publication announcement, Dr. Layman pointed out: "Studies that report there is no difference among diets also report that subjects were not carefully following the diets. It’s very important to realize the difference between diet compliance and diet effectiveness."
The protein diet also proved easier to follow and maintain long-term, with 64 percent of the moderate-protein dieters completing the study compared to 45 percent of dieters using the high-carbohydrate diet, Layman said.
"Subjects on the moderate-protein diet reported that they weren’t as interested in snacks or desserts, and they didn’t have food cravings. When you eat protein, you feel full longer," he said.