Balanced diet includes protein portions at each meal

Just when you thought it was fine to relax with a glass of well-earned wine and nibble on a few whole-grain crackers, nutrition researchers are here to ask, “Did you have enough protein today?”

OK, we know you’re not into body-building competitions, but get a load of this midlife reality check: You could be losing muscle mass and strength —- a condition called sarcopenia —- if you don’t consume enough high-quality protein on a daily basis.

“We’re seeing sarcopenia, which commonly occurs in the elderly, in younger subjects in their early to mid-50s,” said Susan Hewlings, a registered dietitian and assistant professor at Stetson University in Florida who specializes in protein metabolism. Hewlings and other researchers presenting at the 2008 American Dietetic Association’s annual Food and Nutrition Conference shed new light on the connection between what we eat and the health of our aging muscles. Bottom line: Research shows that to prevent and treat lost muscle mass you must consume 1.5 grams of protein for every kilogram of body weight per day. That translates to about 90 grams of protein a day for a normal weight man and would be less if you’re a tiny gal.

Breakfast, lunch, dinner

But here’s where the real specific advice kicks in: You should be including sources of high-quality protein such as eggs, milk and meats and balancing your protein intake throughout the day.

“Typically, people eat less protein at breakfast, a little more at lunch and then eat a lot at dinner,” Hewlings said. “To optimize protein synthesis and prevent sarcopenia, it needs to be more evenly distributed.” There goes that diet plan to starve all day and splurge on a big steak for dinner. Your muscles are hungry for amino acids found in protein foods all day long. In fact, Robert Wolfe, professor of geriatrics at the University of Arkansas for Medical Sciences in Little Rock, warns that “When there are periods of the day when no amino acids are being absorbed from the gut, muscle serves as the only significant reservoir of protein.” That means your body starts robbing the muscles of stored protein to keep organs and other tissues humming along. So make sure you’re eating protein-containing foods every day and including protein in each meal. And that includes snacks. Something as simple as fresh apple slices topped with peanut butter is a good choice.

Hewlings emphasized that protein alone can’t do the job of preserving and building muscles as we age. “I call exercise the ‘poor man’s plastic surgery,’ ” she said. “And note that physical activity boosts lean body mass only if you’ve got enough protein in your diet.”

Keep fat intake down

Since foods are often a combination of the three macronutrients (protein, carbohydrates and fat), choose protein-containing foods wisely with other health concerns in mind. For instance, a 6-ounce broiled porterhouse steak is a great source of complete protein —- 38 grams —- but contains 44 grams of fat. The same amount of salmon gives you 34 grams of protein and 18 grams of fat, and it’s the kind of fat that’s good for you. For a complete list of protein foods to include in a healthy diet, go to www.mypyramid.gov.

Carolyn O’Neil is a registered dietitian and co-author of “The Dish on Eating Healthy and Being Fabulous!” E-mail her at carolyn @carolynoneil.com.