Effect of an Energy-Restricted, Nutritionally Complete, Higher Protein Meal Plan on Body Composition and Mobility in Older Adults With Obesity: A Randomized Controlled Trial

Abstract

Background: Increasing protein content of the diet might be an effective strategy to preserve muscle mass in older adults undergoing caloric restriction, thereby preserving muscle function. Methods: Ninety-six older adults (70.3 ± 3.7 years, 74% women, 27% African American) with obesity (35.4 ± 3.3 kg/m 2 ; 47% total body fat) were randomized to a 6-month higher protein (providing 1.2-1.5 g/kg/d) weight loss (WL) program, utilizing the Medifast 4&2&1 Plan, or to weight stability (WS). Dual-energy x-ray absorptiometry-acquired total body mass and composition, and fast gait speed over 400 m was assessed at baseline, 3, and 6 months. Results: At baseline, dual-energy x-ray absorptiometry-acquired total body, fat, and lean masses were 95.9 ± 14.6, 44.6 ± 7.6, and 48.7 ± 9.5 kg, respectively, and 400-m gait speed was 1.17 ± 0.20 m/s. Total body mass was significantly reduced in the WL group (−8.17 [−9.56, −6.77] kg) compared with the WS group (−1.16 [−2.59, 0.27] kg), with 87% of total mass lost as fat (WL: −7.1 [−8.1, −6.1] kg; −15.9% change from baseline). A differential treatment effect was not observed for change in lean mass (WL: −0.81 [−1.40, −0.23] kg vs WS: −0.24 [−0.85, 0.36] kg). Four-hundred-meter gait speed was also unchanged from baseline although trends suggest slightly increased gait speed in the WL group [0.01 (−0.02, 0.04) m/s] compared with the WS group [−0.02 (−0.05, 0.01) m/s]. Conclusion: Intentional weight loss using a high-protein diet is effective in producing significant total body mass and fat mass loss, while helping preserve lean body mass and mobility, in relatively high-functioning older adults with obesity.

Use of Metabolomic Profiling to Understand Variability in Adiposity Changes Following an Intentional Weight Loss Intervention in Older Adults

“…Indeed, meta-analytic data show that older adults who consume higher levels of protein during weight loss retain more lean mass in comparison to normal protein diets (losses of 21–22% vs. ≥30%) [ 12 ]. In agreement, the data from our group show older adults following a hypocaloric, nutritionally complete, higher protein meal plan experience smaller average lean (~13%) vs. fat (~87%) mass losses; however, the amount and location of fat mass loss was noted to be more variable [ 13 , 14 ]. A better understanding of the variability in adiposity changes as a means to optimize fat mass loss in this context confers high clinical utility.…”

“…Body composition changes in the Medifast ® for Seniors Study have been published previously [ 13 , 14 ]. Seventy-four study participants had complete pre- and post-intervention DXA measures and plasma samples available for the metabolomics analysis.…”

“…This study was approved by the Wake Forest School of Medicine Institutional Review Board (IRB: 33,428 and 54,086), and all participants provided written informed consent prior to enrolment. Primary outcome papers, including study design and dietary details, were previously published [ 13 , 14 , 19 , 20 ]. For the present analyses, we evaluated the metabolomic data from plasma samples drawn at baseline and at the end of the six month dietary intervention for 74 individuals with complete Dual-Energy X-Ray Absorptiometry (DXA)-derived body composition data.…”

Effect of a hypocaloric, nutritionally complete, higher-protein meal plan on bone density and quality in older adults with obesity: a randomized trial

“…This study (NCT02730988) was a 6-mo parallel RCT conducted at Wake Forest University to compare the effects of a nutritionally complete, higher-protein meal plan during weight loss, as opposed to weight stability, on changes in mobility, total body mass, fat mass, lean mass, BMD, and TBS in 96 participants using a 1:1 allocation ratio. The study design, baseline characteristics, and intervention effects on mobility (primary outcome assessed using the fast 400-m walk test) and body composition (total body, fat, and lean mass) are reported in a separate publication (27). The current study represents an ancillary analysis and focuses on the interventional effect on BMD and TBS outcomes.…”

Effective SLOPE: EffectS of Lifestyle interventions in Older PEople with obesity: a systematic review and network meta-analysis protocol

“…The only published meta-analysis dates back to 2010, 63 and there is no meta-analysis available for functional outcomes in older people with obesity. Considering, recently published intervention studies, for example, Ard et al 67 and Beavers et al, 68 it is likely that accumulated evidence enables quantitative syntheses.…”