Effects of Adherence to a Higher Protein Diet on Weight Loss, Markers of Health, and Functional Capacity in Older Women Participating in a Resistance-Based Exercise Program

Abstract

Resistance training and maintenance of a higher protein diet have been recommended to help older individuals maintain muscle mass. This study examined whether adherence to a higher protein diet while participating in a resistance-based exercise program promoted more favorable changes in body composition, markers of health, and/or functional capacity in older females in comparison to following a traditional higher carbohydrate diet or exercise training alone with no diet intervention. In total, 54 overweight and obese females (65.9 ± 4.7 years; 78.7 ± 11 kg, 30.5 ± 4.1 kg/m2, 43.5 ± 3.6% fat) were randomly assigned to an exercise-only group (E), an exercise plus hypo-energetic higher carbohydrate (HC) diet, or a higher protein diet (HP) diet. Participants followed their respective diet plans and performed a supervised 30-min circuit-style resistance exercise program 3 d/wk. Participants were tested at 0, 10, and 14 weeks. Data were analyzed using univariate, multivariate, and repeated measures general linear model (GLM) statistics as well as one-way analysis of variance (ANOVA) of changes from baseline with [95% confidence intervals]. Results revealed that after 14 weeks, participants in the HP group experienced significantly greater reductions in weight (E −1.3 ± 2.3, [−2.4, −0.2]; HC −3.0 ± 3.1 [−4.5, −1.5]; HP −4.8 ± 3.2, [−6.4, −3.1]%, p = 0.003), fat mass (E −2.7 ± 3.8, [−4.6, −0.9]; HC −5.9 ± 4.2 [−8.0, −3.9]; HP −10.2 ± 5.8 [−13.2, –7.2%], p < 0.001), and body fat percentage (E −2.0 ± 3.5 [−3.7, −0.3]; HC −4.3 ± 3.2 [−5.9, −2.8]; HP −6.3 ± 3.5 [−8.1, −4.5] %, p = 0.002) with no significant reductions in fat-free mass or resting energy expenditure over time or among groups. Significant differences were observed in leptin (E −1.8 ± 34 [−18, 14]; HC 43.8 ± 55 [CI 16, 71]; HP −26.5 ± 70 [−63, −9.6] ng/mL, p = 0.001) and adiponectin (E 43.1 ± 76.2 [6.3, 79.8]; HC −27.9 ± 33.4 [−44.5, −11.3]; HP 52.3 ± 79 [11.9, 92.8] µg/mL, p = 0.001). All groups experienced significant improvements in muscular strength, muscular endurance, aerobic capacity, markers of balance and functional capacity, and several markers of health. These findings indicate that a higher protein diet while participating in a resistance-based exercise program promoted more favorable changes in body composition compared to a higher carbohydrate diet in older females.

Differential Impact of Calcium and Vitamin D on Body Composition Changes in Post-Menopausal Women Following a Restricted Energy Diet and Exercise Program

“…As consistent with several previously published studies [14,15,[40][41][42][43][44] from our research group over the past ten years and has encompassed over 750 research participants, participants in this study were assigned at baseline in a block fashion according to age and body mass: (1) No dietary modification (CTL); (2) A low-calorie, higher-protein (LCHP) diet consisting of 15% carbohydrates, 55% protein, and 30% fat); or, (3) A low-calorie, higher-carbohydrate (LCHC) diet consisting of 55% carbohydrates, 15% protein, and 30% fat). Across the entire 14-week study protocol, the LCHP and LCHC diets consisted of 1200 kcal/day for 1 week and 1600 kcal/day for 9 weeks.…”

Prevention and Treatment of Sarcopenic Obesity in Women

“…The only intervention that was definitely effective in the prevention of all components of sarcopenia was the combination of RT (thrice weekly) with either a normal (0.8 g/kg) or high protein (1.2 g/kg) hypocaloric diet, leading to significant improvements in muscular strength, endurance, aerobic capacity, balance and functional capacity [49]. Also, in the absence of dietary intervention, RT reduces fat mass, increases muscle strength and improves functional capacity in women at risk of SO.…”

“…A third group had RT only. All three groups underwent significant improvements in muscular strength, muscular endurance, aerobic performance, balance and functional capacity [49].…”

Sarcopenia during COVID-19 lockdown restrictions: long-term health effects of short-term muscle loss

“…Reducing total calorie intake through a reduction in portion sizes and snacking occasions may be effective methods for maintaining energy balance in the elderly [365]. Maintaining higher protein intakes may be particularly beneficial for avoiding the loss of lean mass during such calorie restriction [366,367], especially when combined with (home-based) RE which is known to help preserve LM [368,369]. Where possible, focusing on more whole foods, such as fruit, vegetables, whole grains, and legumes, has been shown to help reduce ad libitum food intake, while also benefiting cardiometabolic health [370].…”