Effects of higher habitual protein intake on resistance-training-induced changes in body composition and muscular strength in untrained older women: A clinical trial study

Abstract

Background: Aging is accompanied by progressive and accentuated decline in muscular strength and skeletal muscle mass, affecting health and functional autonomy. Both resistance training (RT) and diet are strategies that may contribute to improvement in the health of the elderly. Aim: The purpose of this study was to evaluate the effects of higher habitual protein intake on RT-induced changes in body composition and strength in untrained postmenopausal women. Methods: Seventy older women were submitted to an RT program. Body composition, muscular strength, and dietary intake (24 h dietary recall) were performed pre-and post-intervention. To verify different intervention effects according to protein intake of the participants, the sample was separated into tertiles according to protein intake: low, moderate, and high protein intake. Results: A time vs. group interaction (p < 0.05) was observed, with high protein intake presenting greater increases compared with low protein intake, for skeletal muscle mass (5.3% vs. 1.3%), lower limb lean soft tissue (4.9% vs. 1.4%), upper lean soft tissue (4.9% vs. 1.2%), preacher curl (24% vs. 15.2%), and total strength (16.4% vs. 11.7%). A time vs. group interaction (p < 0.05) was observed, with high protein intake presenting greater increases compared with moderate protein intake, for skeletal muscle mass (5.3% vs. 3.2%). In all groups, a main effect of time (p < 0.05) was observed for knee extension and chest press. Conclusions: We conclude that intake of >1.0 g/kg/day of protein promotes gains in skeletal muscle mass and muscular strength after RT in untrained older women.

Cocoa-rich chocolate and body composition in postmenopausal women: a randomised clinical trial

“…Other interventions, such as the one designed by Seimon et al (8) , combine physical activity with energy restriction and with a slight increase of protein intake, obtaining improvements in body weight and fat mass. This moderate increase in the intake of proteins has also been reported by other authors as a possible cause of body fat percentage decrease (9) . The modification of the amounts of macronutrients in the habitual diet was pointed out in the Women's Health Initiative Dietary Modification Trial (10) , where the group of postmenopausal women assigned to an intervention based on lower fat intake (<20 % energy) obtained a decrease in body fat percentage and body fat mass after 1 year of follow-up.…”

Comparison of 2 Weekly Frequencies of Resistance Training on Muscular Strength, Body Composition, and Metabolic Biomarkers in Resistance-Trained Older Women: Effects of Detraining and Retraining

“…To reduce errors in the estimation of habitual consumption, which were obtained through the 24-hour dietary recall, the multiple source method (https://msm.dife.de/) statistical program was used, a new analytical method to estimate usual food consumption. This program generates information regarding the estimated habitual intake of an individual, from the combination of probabilities, using repetitions of 24-hour dietary recall or food records (37). All subjects were asked to maintain their regular diet throughout the investigation period.…”

The Impact of Resistance Training on Body Composition, Muscle Strength, and Functional Fitness in Older Women (45–80 Years): A Systematic Review (2010–2020)

“…Interventions ranged from 8 to 32 weeks, with an average intervention length of 15 weeks. The majority of interventions were of medium length (>12 weeks but <25 weeks) (n = 34), three interventions were categorized as short length (<12 weeks) [33,34,43], and one intervention was categorized as long length (>25 weeks) [51]. Intervention length was calculated as the number of weeks actively engaged in RT.…”

“…Eight (8) studies examined the impact of protein combined with resistance training on body composition, strength or functional fitness. Nabuco et al examined the impact of RT plus existing dietary protein levels [43], whereas others fortified dietary intake with protein [30,35,41,42,44,56] or amino acid supplements [38]. Two studies examined the impact of creatine plus resistance training on body composition, strength, or functional fitness [21,37].…”