Date Full Report Received


Date Abstract Report Received



Primary Investigator:

The impact of obesity on women’s health is an important research priority for the National Pork Board; relative to men, women have higher rates of obesity and sustain greater physical impairment as a result. Thus, the overarching goal of the “Protein Optimization in Women Enables Results – Using Protein” (POWR-UP) trial was to explore the potential for higher protein intake at meals to enhance the outcomes of weight reduction in a high risk population, namely women with obesity complicated by weakened muscles. When a high body fat occurs along with reduced muscle mass/function (known as “sarcopenic obesity”), weight loss treatment can be risky. Not just fat will be lost; usually 25% or more of the weight will be lost as lean tissue such as muscle. The POWR-UP trial is built on the theory that generous animal protein (~ 30 grams) at every meal will promote better muscle outcomes during weight loss in terms of size and function; in the case of sarcopenic obesity, this should convey a definite advantage. So POWR-UP compared a traditional weight loss diet to one with 30 grams of high quality protein at each meal during a 6 month obesity reduction in 80 middle-aged and older women (ages 45 to 78 yrs). For two of three meals each day, the protein source was lean pork tenderloin, deli ham, pork chops, and ground pork; the outcome assessments at 4 and 6 months emphasized physical function and body composition.

Results: POWR-UP ended December, 2015, and the results are now being analyzed and reported. We found that the high protein weight loss diet was very well accepted and thus successfully implemented. Protein intakes in the high protein group exceeded the target, with average intakes of 31, 35, and 40 g for breakfast, lunch, and dinner. More importantly, both groups lost significant amounts of body weight and robustly improved their function. The primary measure of function (distance walked in 6 minutes) was significantly increased at 4 months in the high protein group; by 6 months the control group also improved. Many other function tests improved in both groups; body fat and waist circumference were also reduced. Another interesting finding was that older women tended to lose more weight but in a slower manner than younger participants. In summary, our findings support the feasibility and the strong potential functional benefits of including a protein-enhanced weight loss regimen in obesity interventions for older women.

Significance of findings for the industry: The POWR-UP trial is the first to use pork protein to promote muscle function during an intervention for sarcopenic obesity. It provides a valuable illustration of the health-related attributes of lean pork, such as acceptance, use for weight control, and functional benefits as much or greater than with the control diet. These benefits occurred using a diet with 2 servings of lean pork every day for 6 months. Our findings agree with growing scientific evidence (including from our laboratory) that an optimal quality, quantity, and meal distribution of protein aids muscle protein synthesis and function, and likely other metabolic systems as well. If these findings continue to be extended and confirmed, they will lend important support to an upwards revision of protein intake recommendations for older adults, a very important advantage to the industry as a whole.

Connie W. Bales, Ph.D., R.D.
Professor of Medicine, Duke University Medical Center
bales001 @mc.duke.edu