Meal-based enhancement of protein quality and quantity during weight loss in obese older adults with mobility limitations: rationale and design for the MEASUR-UP trial

Abstract

Obese older adults with even modest functional limitations are at a disadvantage for maintaining their independence into late life. However, there is no established intervention for obesity in older individuals. The Measuring Eating, Activity, and Strength: Understanding the Response - Using Protein (MEASUR-UP) trial is a randomized controlled pilot study of obese women and men aged ≥60 years with mild to moderate functional impairments. Changes in body composition (lean and fat mass) and function (Short Physical Performance Battery) in an enhanced protein weight reduction (Protein) arm will be compared to those in a traditional weight loss (Control) arm. The Protein intervention is based on evidence that older adults achieve optimal rates of muscle protein synthesis when consuming about 25-30 g of high quality protein per meal; these participants will consume ~30 g of animal protein at each meal via a combination of provided protein (beef) servings and diet counseling. This trial will provide information on the feasibility and efficacy of enhancing protein quantity and quality in the context of a weight reduction regimen and determine the impact of this intervention on body weight, functional status, and lean muscle mass. We hypothesize that the enhancement of protein quantity and quality in the Protein arm will result in better outcomes for function and/or lean muscle mass than in the Control arm. Ultimately, we hope our findings will help identify a safe weight loss approach that can delay or prevent late life disability by changing the trajectory of age-associated functional impairment associated with obesity.

Trial registration: ClinicalTrials.gov NCT01715753.

Keywords: Function; Obesity; Older adults; Protein; Sarcopenic obesity; Weight loss intervention.

Copyright © 2014 Elsevier Inc. All rights reserved.

Figures

Figure 1

In older adults, optimal protein synthesis in muscle is achieved at a target intake of 30g or more of high-quality protein. On the left is a schematic illustration of how typical protein intakes (solid line) may reach the optimal protein synthesis threshold no more than once a day resulting in an overall diminished anabolic response (dashed line). In contrast, as illustrated on the right, the MEASUR-UP high protein regimen intakes are planned to meet the threshold at each of three meals per day. The expectation, illustrated by the arrow on the right, is that the enhanced protein intervention will promote retention of lean mass and improve function

Figure 2

This schematic flowchart explains the sequence of steps for baseline assessments, enrollment and randomization, and subsequent assessments being conducted in the MEASUR-UP trial. The assessments to be conducted are detailed under Visits 1, 2, and 3 and the questionnaires to be administered are listed in the box on far right.

Figure 3

This photograph shows the cooked lean beef products that will be provided to a Protein group participant for one week following a 1600 to 1700 kcal diet prescription. Included are 22.5 oz. ground beef, 14 oz. deli roast beef, and 36 oz. flank steak, all pre-cooked and either chilled or frozen and provided in an insulated bag for transport to home.

Figure 4

The enrollment criteria for MEASUR-UP specify that eligible participants have “age-normal” renal function. We developed this algorithm using glomerular filtration rate (GFR) to guide decisions about initial enrollment and monitoring during the trial. All those with a GFR of ≥60 ml/min/1.73 m2 are study eligible. For enrollees with a GFR in the range of 45-59 ml/min/1.73 m2, GFR measurements will be repeated every two months; a drop of 10% or more or falling to a level <45 ml/min/1.73 m2 will disqualify the individual from further study participation.