A whey protein-based multi-ingredient nutritional supplement stimulates gains in lean body mass and strength in healthy older men: A randomized controlled trial

The researchers tested a multi-ingredient nutritional supplement (SUPP) against a calorie-matched placebo drink (CON) in healthy older men. The supplement contained:

• 30 grams of whey protein
• 2.5 grams of creatine
• 500 IU of vitamin D
• 400 mg of calcium
• 1500 mg of omega-3 polyunsaturated fatty acids (n-3 PUFA), specifically 700 mg eicosapentaenoic acid (EPA) and 445 mg docosahexaenoic acid (DHA)

The control drink contained 22 grams of maltodextrin (a simple carbohydrate) and safflower oil (which has no omega-3s). Both drinks were matched for flavour and odour to keep participants and researchers blinded.

The study had two phases:

• Phase 1 (6 weeks): Supplement or placebo alone, with no exercise.
• Phase 2 (12 weeks): Continued supplement or placebo, but now combined with a supervised exercise program (twice-weekly resistance training plus once-weekly high-intensity interval training on a bike).

The primary outcomes were:

• Isotonic strength: Measured as one-repetition maximum (1RM) for leg press, chest press, lateral pull-down, horizontal row, shoulder press, and leg extension. They summed these into a "total 1RM" (Σ1RM) and also looked at upper-body and lower-body separately.
• Lean body mass (LBM): Measured by dual-energy X-ray absorptiometry (DXA), a body composition scan.

Secondary outcomes included aerobic fitness (peak oxygen uptake, VO₂peak), physical function tests, metabolic health (oral glucose tolerance test), dietary intake, and habitual physical activity.

• Sample size: 49 healthy older men (25 in the supplement group, 24 in the control group). 42 completed the full 20-week study (22 SUPP, 20 CON).
• Age: 73 ± 1 years (mean ± standard error of the mean)
• Body mass index (BMI): 28.5 ± 1.5 kg/m² (overweight range)
• Setting: McMaster University, Hamilton, Ontario, Canada. Study ran from December 2014 to September 2016.
• Inclusion criteria: Men aged ≥60 years, non-smokers, BMI 18.5–30.0 kg/m², normal resting blood pressure or stage I hypertension (systolic 140–159 mmHg, diastolic 90–99 mmHg), no structured resistance or aerobic exercise training in the previous 6 months.
• Exclusion criteria: Significant weight change in past 6 months; regular use of NSAIDs, simvastatin, atorvastatin, or anticoagulants; injuries preventing safe exercise; diabetes; cancer; infectious disease; unstable cardiac or gastrointestinal disease. Participants had to pass an oral glucose tolerance test (fasting glucose <7.0 mM, 2-hour glucose <11.1 mM) and a maximal exercise stress test.

• Isotonic strength: One-repetition maximum (1RM) testing on standard weight-stack machines for leg press, chest press, lateral pull-down, horizontal row, shoulder press, and leg extension. 1RM is the maximum weight a person can lift once with proper form.
• Lean body mass: Dual-energy X-ray absorptiometry (DXA) — a low-dose X-ray scan that distinguishes bone, fat, and lean tissue. This is the gold-standard method for body composition assessment.
• Aerobic fitness: Peak oxygen uptake (VO₂peak) measured during a graded exercise test on a cycle ergometer, with breath-by-breath gas analysis.
• Physical function: A battery of tests including timed up-and-go, stair climb, and 6-minute walk test.
• Metabolic health: 75-gram oral glucose tolerance test (OGTT) — fasting blood draw, then drinking a sugary solution, with blood draws at 30, 60, 90, and 120 minutes to measure glucose and insulin.
• Dietary intake: Three-day food records (two weekdays, one weekend day) analysed for total energy, protein, fat, carbohydrate, and micronutrients.
• Habitual physical activity: Accelerometers worn for 7 days at each testing time point.
• Compliance: Participants returned empty sachets and oil bottles; they also completed daily logs. Compliance was >99% for both groups.

Study design: This was a randomized, double-blind, placebo-controlled, parallel-group trial with two phases. Randomization used a block design (block size of 10) generated by a computer algorithm. The randomization code was held by an investigator not involved in recruitment, training, or testing. Both participants and all researchers who interacted with participants were blinded to group assignment.

Phase 1 (weeks 0–6): Participants consumed either SUPP or CON twice daily — once one hour after breakfast and again one hour before bed. No exercise was prescribed. This phase tested whether the supplement alone could increase strength and lean mass without any exercise stimulus.

Phase 2 (weeks 7–19): Participants continued their assigned beverages while completing a 12-week supervised exercise program. Exercise consisted of:

• Resistance training (twice weekly, Monday and Friday): 5-minute cycle warm-up, then 3 sets of 4 exercises (leg press, chest press or lateral pull-down, horizontal row or shoulder press, and leg extension). The third set of each exercise was performed to volitional fatigue (failure). Workload started at 65% of 1RM (10–12 reps) and progressed to 80% of 1RM (6–8 reps) over the first 3 weeks. Loads were adjusted based on 1RM re-tests or when participants could complete ≥12 reps on the third set.
• High-intensity interval training (once weekly, Wednesday): 3-minute warm-up at 25W, then 10 x 60-second intervals at a workload eliciting ~90% of maximal heart rate, with 60 seconds of active recovery between intervals. Participants maintained a cadence of ≥90 rpm.

Testing occurred at three time points: Week -1 (baseline), Week 6 (end of Phase 1), and Week 19 (end of Phase 2).

Statistical approach: The researchers used a two-way repeated-measures ANOVA (group × time) to compare changes between groups. For Phase 1, they compared SUPP vs. CON from baseline to week 6. For Phase 2, they compared SUPP+EX vs. CON+EX from week 6 to week 19, and also from baseline to week 19. They used Bonferroni post-hoc tests for significant interactions. Sample size was calculated a priori: 19 participants per group were needed to detect a 3.25 kg increase in leg press strength (SD 1.5 kg) with 80% power at α=0.05. They aimed for 25 per group to account for 20% dropout.

What this design can and cannot prove:

• Can prove: Because of randomization and double-blinding, this design can establish causality — the supplement caused the observed changes in strength and lean mass, not some other factor. The two-phase design is clever: Phase 1 isolates the effect of the supplement alone (no exercise confound), while Phase 2 tests whether supplement plus exercise is better than placebo plus exercise.
• Cannot prove: The design cannot separate which ingredient(s) in the multi-ingredient supplement drove the effects. Was it the whey protein? The creatine? The omega-3s? The vitamin D? The combination? You'd need a factorial design (testing each ingredient separately and in combination) to answer that. Also, the study only included men, so results may not generalize to women. The exercise program was supervised and progressive, so results may not apply to unsupervised or less structured exercise. Finally, the 20-week duration cannot speak to long-term effects beyond that window.

Methodological strengths: Excellent compliance (>99%), double-blinding maintained, objective primary outcomes (DXA, 1RM testing), a priori power calculation, and a well-characterized population.

Methodological weaknesses: Small sample size (49 started, 42 completed), which limits statistical power for subgroup analyses. The control drink contained maltodextrin (22g of carbohydrate), which is not entirely inert — it provides calories and could theoretically affect insulin or muscle glycogen, though this is unlikely to mimic the anabolic effects of the supplement. The study was funded by a university aging initiative and a Canadian government grant, but one author (SMP) reported receiving honoraria from the US National Dairy Council — a potential conflict of interest, though the funders had no role in study design or analysis.

Primary outcomes — Phase 1 (supplement alone, weeks 0–6):

• Total strength (Σ1RM): SUPP group gained +14 ± 4 kg; CON group gained +3 ± 2 kg. This difference was statistically significant (P < 0.001).
• Lean body mass (LBM): SUPP group gained +1.2 ± 0.3 kg; CON group lost -0.1 ± 0.2 kg. This difference was statistically significant (P < 0.001).

Primary outcomes — Phase 2 (supplement + exercise vs. placebo + exercise, weeks 7–19):

• Both groups gained strength during the exercise phase, but the SUPP+EX group ended with significantly greater upper-body strength than the CON+EX group (Σ upper body 1RM: 119 ± 4 kg vs. 109 ± 5 kg, P = 0.039).
• Lower-body strength gains were not significantly different between groups during Phase 2 (leg press 1RM: SUPP+EX 155 ± 6 kg vs. CON+EX 148 ± 7 kg, P = 0.43).
• Lean body mass changes during Phase 2 were not reported separately in the abstract, but the full paper indicates that both groups gained LBM with exercise, with no significant difference between groups during this phase.

Secondary outcomes:

• Aerobic fitness (VO₂peak): Both groups improved with HIIT training, with no significant difference between groups.
• Physical function: Both groups improved on timed up-and-go, stair climb, and 6-minute walk, with no significant between-group differences.
• Metabolic health (OGTT): No significant changes in glucose or insulin responses in either group.
• Body fat: No significant changes in fat mass in either group.
• Adverse events: No serious adverse events related to the supplement. One participant in the CON group withdrew due to gastrointestinal discomfort.

Let's translate these numbers into plain English:

• Strength gain without exercise: Over 6 weeks of just taking the supplement (no gym), the supplement group gained about 14 kg (31 lbs) in total strength across all exercises. That's roughly the equivalent of being able to leg press an extra 14 kg — about the weight of a medium-sized bowling ball. The control group gained only 3 kg (6.6 lbs), which could be a learning effect from repeating the 1RM test.
• Lean mass gain without exercise: The supplement group gained 1.2 kg (2.6 lbs) of lean tissue in 6 weeks — that's about 200 grams per week, or roughly the lean mass of a small apple per week. The control group lost a negligible 0.1 kg.
• Upper-body strength with exercise: After 12 weeks of training, the supplement-plus-exercise group had about 10 kg (22 lbs) more upper-body strength than the placebo-plus-exercise group. That's the difference between being able to bench press a 10 kg dumbbell more than someone else.

To put this in perspective: typical age-related muscle loss in men over 70 is about 1-2% per year. A 1.2 kg gain in lean mass over 6 weeks represents roughly a 2-3% increase in total lean mass — effectively reversing about 1-2 years of age-related muscle loss in just 6 weeks, without even exercising.

What the authors acknowledge:

• The study cannot determine which ingredient(s) drove the effects — it was designed to test the "package," not individual components.
• The sample was exclusively men, so results may not apply to women.
• The study was relatively short (20 weeks total), so long-term effects are unknown.
• The exercise program was supervised and intensive — results may not generalize to unsupervised or less structured exercise.

What a critical reader would note:

• Small sample size: 49 participants started, 42 completed. This limits statistical power, especially for subgroup analyses or detecting differences in secondary outcomes.
• Control drink not truly inert: The maltodextrin placebo (22g carbohydrate per serving, 44g per day) provides calories and could theoretically affect insulin or glycogen, though this is unlikely to explain the large differences observed.
• Industry funding conflict: One author (SMP) reported receiving honoraria from the US National Dairy Council, which promotes dairy protein. While the study funders had no role in design or analysis, this is a potential source of bias.
• No measure of muscle protein synthesis: The study measured outcomes (strength, lean mass) but not the underlying mechanisms (e.g., rates of muscle protein synthesis), so we don't know exactly how the supplement worked.
• Compliance was self-reported: Participants returned empty sachets and bottles, but there's no biomarker verification (e.g., blood levels of creatine or omega-3s) to confirm they actually consumed the supplements.
• Generalizability limited to healthy older men: These were relatively healthy, non-diabetic, non-obese men who passed a stress test. Results may not apply to frail older adults, women, younger people, or those with chronic diseases.
• No long-term follow-up: We don't know if gains were maintained after the supplement or exercise stopped.

For someone running their own n=1 experiment (testing on yourself):

What to test

A multi-ingredient supplement stack taken twice daily:

• Morning dose (1 hour after breakfast): 30g whey protein + 2.5g creatine monohydrate + 500 IU vitamin D3 + 400mg calcium + 1500mg omega-3s (with ~700mg EPA and ~445mg DHA)
• Evening dose (1 hour before bed): Same as above

Alternatively, you could test individual components to isolate effects:

• Test 1: Whey protein alone (30g twice daily) vs. placebo
• Test 2: Add creatine (5g daily) to whey
• Test 3: Add omega-3s (3g daily) to whey + creatine

Minimum meaningful duration

• For lean mass changes: At least 6 weeks. The study saw clear gains by week 6. DXA scans can detect changes in as little as 2-4 weeks, but 6 weeks gives a reliable signal.
• For strength changes: 4-6 weeks for neural adaptations (learning the movement), 8-12 weeks for true hypertrophy-driven strength gains.
• For a full self-experiment: Run for 12-20 weeks to match the study's timeline and see both supplement-alone and supplement-plus-exercise effects.

What to measure (specific metrics)

• Primary outcome 1 — Lean body mass: Get a DXA scan at baseline and at the end. If DXA is unavailable, use a bioelectrical impedance (BIA) scale (less accurate but still useful) or skinfold calipers. Measure at the same time of day, same hydration status, same time since last meal.
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