Plant Based Protein and Whey Protein: Effects on Body Composition and Performance
Condition: Protein Supplementation
Study type: Interventional

Summary: 
      This study aimed to investigate the effects of a newly developed plant-based protein blend
      regarding health and safety, body composition, and performance on healthy and physically
      active adult individuals, specifically team sports athletes. A randomized, double-blind,
      controlled trial was used to compare the effects of the plant-based protein versus whey
      protein, after an 8-week supplementation protocol, on body composition, biochemical markers,
      muscle strength and power, as well as aerobic performance in male futsal players. The working
      hypothesis is that this special blend of plant-based protein will be equivalent to whey
      protein, not only regarding body composition and performance, but also insofar as health and
      safety at the biochemical and physiological level.
    

Detailed description: 
      A randomized, double-blind, controlled trial was performed to investigate health and safety
      following supplementation with a newly developed plant-based protein blend and to compare the
      effects of this plant-based protein versus whey protein, after an 8-week supplementation
      protocol, on body composition and performance. Prior to intervention, volunteers' general
      health and ability to participate in the study were assessed. The study involved 50 male
      futsal players currently engaged in a training program and competing. Before engaging the
      8-week supplementation protocol, participants underwent measurements of body composition,
      strength and power, and aerobic performance, as well as a full profile of biochemical health
      markers, and assessment of food and fluid intake. Evaluations were repeated after 4 weeks,
      for follow up and to detect potential compliance issues, and after 8 weeks of
      supplementation. Assessments took place in the morning (starting at 7:00 a.m.) after an
      overnight fast, except for the performance tests, which were performed following consumption
      of a standard, meal replacement bar.

      Anthropometry and Body Composition - Wearing minimal clothing and no shoes, participants had
      their weight and height measured on a scale and stadiometer (Seca, Hamburg, Germany),
      respectively. Body composition, namely bone mineral content, fat mass and fat free mass, were
      evaluated by dual energy X-ray absorptiometry (DXA) (Horizon Wi, Hologic, Waltham, USA) and
      skeletal muscle through the evaluation of the muscle thickness of the rectus femoris by
      ultrasonography (model WED-180 HL, Shenzhen,China). Total body water and its intra and
      extracellular compartments were estimated from whole body resistance (R) and reactance (Xc),
      measured through bioelectrical impedance analysis (BIA), using a single frequency device of
      50 kHz (BIA-101, RJL/Akern Systems, Firenze, Italy). From the raw R and Xc data, the phase
      angle was additionally determined, using the Akern Software.

      Muscle Strength and Power, and Aerobic Performance - Strength was assessed using the handgrip
      strength test, as well as the back squat and bench press 1 repetition maximum (1 RM). The
      handgrip strength test was used to evaluate the maximal isometric force of the muscles of the
      hand and forearm. Using a portable hand dynamometer (JAMAR, Sammons Preston, Bolingbrook, IL,
      USA), participants were assessed for both hands alternately, in a stand-up position. The
      maximal force generated out of 3 attempts was considered for analysis. Additionally, muscle
      strength was evaluated by 1RM back squat and bench press in a Multipower machine, using a
      velocity-based training device (Vitruve Encoder, Madrid, Spain). Muscle power was assessed
      during maximal cycling (Wingate test) and jumping movements. During the Wingate test,
      participants were instructed to cycle (Monark 894 Peak Bike, Vansbro, Sweden) against a
      predetermined resistance (7.5% body weight), as fast as possible, for 30 seconds. Vertical
      jumps, namely the squat jump, countermovement jumps using both legs and single legs, as well
      as the Abalakov countermovement jump, were performed on a multicomponent force platform
      (Chronojump Boscosystem, Barcelona, Spain) interfaced with a computer. The best out of 3
      attempts was also considered for analysis of this methodology. Aerobic performance was
      assessed by VO2peak and maximal aerobic speed (MAS), determined using a breath-by-breath gas
      analyzer (Quark, Cosmed, Italy) in an incremental test performed on a treadmill (Axelero,
      MEDEN-INMED, Koszalin, Poland). After 3 minutes of warm-up at 5 km/h, participants began the
      test at 6 km/h and 2% inclination. Each minute, the speed increased 1 km/h until volitional
      exhaustion. The VO2peak was considered the highest 30 sec average value of VO2 and MAS, the
      speed at the last completed stage.

      All tasks were performed by the participants with direct supervision of sport scientists
      and/or exercise physiologists, with prior knowledge of the methodologies, and experience
      handling the equipments and corresponding softwares.

      Biochemical Markers - For biochemical health markers, saliva and whole blood, in EDTA tubes,
      were collected per the standard protocols. . From whole blood, plasma was separated when
      necessary. Blood measurements included hematocrit, glucose, C-reactive protein (CRP),
      aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatine kinase (CK), and
      creatinine, using spectrophotometry techniques in an automated equipment (Vario Photometer II
      DP310, Diglobal Gmbh, Berlin, Germany). Saliva was collected for cortisol evaluation in
      Enzyme-Linked Immunosorbent Assay (ELISA) commercial kits (Salimetrics, PA, USA).

      Nutritional Assessment - Following extensive verbal and written instructions, diet control
      and food patterns were characterized using 3-day food records (2 non-consecutive weekdays and
      1 weekend day). Participants were instructed to maintain their dietary pattern for the 8
      weeks of the study. Energy, macronutrient, and micronutrient intake were quantified using a
      dietary analysis software (Nutritics Research Edition (v5.09), Dublin, Ireland).

      Randomization and Supplementation - Eligible participants were assigned to one of the two
      arms of the study using a covariate adaptive randomization procedure considering the
      covariates age, handgrip strength, whole body fat-free mass, and whole-body fat mass
      percentage. The investigator responsible for the sample randomization and supplements
      distribution was not directly involved in participants' eligibility interview or data
      collection. The supplementation protocol was similar for both the plant-based and whey
      protein, with the uptake of a single dose of ~30 g occurring 30-60 min after physical
      practice on training days or 30-60 min before bedtime on rest days. Supplementation
      compliance was assessed by questionnaire at the end of weeks 4 and 8.

      Sample Size Justification - Previous, similar studies showed no differences between the
      abovementioned supplements regarding the analyzed variables of interest. In cases where there
      are no differences between the arms of the study, an effect size does not exist, so a power
      analysis is not a valid approach. As our hypothesis is that there will be no difference
      between the newly developed plant-based protein blend and whey protein, we can consider a
      non-inferiority trial and, therefore, our sample size can be similar to that of previous
      studies. Additionally, despite the time course of muscle hypertrophy not being exactly known,
      an 8-week intervention would be considered the minimum timeline for true hypertrophy to be
      detectable/measurable after 6-8 weeks of resistance training (using medical imageology i.e.,
      ultrasound). Furthermore, it has been reported that to detect hypertrophy differences
      following supplementation with proteins of different quality, the number of subjects needed
      should be in the range of at least 25 per group. We have chosen to go with a robust approach.
      Therefore, our proposed sample size is of 25 participants per group.

      Statistics - All statistical analyses are being carried out using IBM SPSS Statistics
      (Version 25.0, NY, IBM). Basic descriptive data were run to characterize the study
      participants. All variables were checked for normality, using Kolmogorov-Smirnov test.
      Participants were assigned to either a plant-based protein (n = 25) or animal protein group
      (n = 25), based on handgrip strength, age, fat mass or fat-free mass using a stratified
      random assignment. Independent Sample T tests will be applied to compare means between
      supplementation groups, at baseline. Time and time-by-group interactions will be evaluated by
      repeated-measures ANOVA. The equality of the matrix of variance and sphericity will be
      explored with the Levene F test and Mauchly's test, respectively. Overall significance level
      for α will be set at p ≤ 0.05.
    

Intervention name(s): Plant based protein; Whey protein
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): A single dose of ~30 g of a plant-based protein blend was ingested 30-60 min after physical practice in training days or 30-60 min before bedtime in resting days.; A single dose of ~30 g of whey protein was ingested 30-60 min after physical practice in training days or 30-60 min before bedtime in resting days.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Basic Science
Keywords: Plant-based Protein; Body composition; Physical Performance; Biochemical Health Markers; Supplementation