Does whey protein supplementation during resistance exercise have additional benefits for decreasing hepatic fat content?

Figures & data

Table 1. Resistance exercise program.

1^st day	2^nd day	3^rd day	4^th day	5^th day	6^th day	7^th day
Chest	Lower limb	Shoulder	Chest	Lower limb	Shoulder	Rest
Week 1–2 (60% 1-RM)
Smith bench-press	Squat	Smith shoulder press	Smith bench-press	Squat	Smith shoulder press
Incline bench-press	Leg press	Dumbbell press	Incline bench-press	Leg press	Dumbbell press
Push-up	Lunge	Dumbbell lateral raise	Push-up	Lunge	Dumbbell lateral raise
Back	Abdominal	Arm	Back	Abdominal	Arm
Seated row	Crunch	Cable curl	Seated row	Crunch	Cable curl
Barbell row		Cable push-down	Barbell row		Cable push-down
Lat pull-down		Kick back	Lat pull-down		Kick back
Week 3–4 (70% 1-RM)
Smith bench-press	Squat	Smith shoulder press	Smith bench-press	Squat	Smith shoulder press
Incline bench-press	Leg press	Dumbbell press	Incline bench-press	Leg press	Dumbbell press
Push-up	Lunge	Dumbbell lateral raise	Push-up	Lunge	Dumbbell lateral raise
Bench-press	Jump squat	Dumbbell front raise	Bench-press	Jump squat	Dumbbell front raise
Back	Abdominal	Arm	Back	Abdominal	Arm
Seated row	Crunch	Cable curl	Seated row	Crunch	Cable curl
Barbell row		Cable push-down	Barbell row		Cable push-down
Lat pull-down		Kick back	Lat pull-down		Kick back
Dumbbell row		Hammer curl	Dumbbell row		Hammer curl
5 min of warm-up, 50 min of main exercise, and 5 min of cool-down 10–12 repetitions, 5 sets, and 1–2 min of rest between the sets

RM, repetition maximum.

Figure 1. Study process.

Table 2. Body composition and resting metabolism.

	Group	Pre	Post	Paired t-test			Repeated ANOVA
				t	p	ES	F (T×G)	p
Body weight (kg)	PSG (n = 18)	73.0 ± 2.5	71.1 ± 2.3	-4.837	< .001	1.140	0.461	.502
	CG (n = 16)	72.8 ± 4.2	71.3 ± 3.5	-4.200	.001	1.050
Body fat (kg)	PSG (n = 18)	16.1 ± 4.5	14.1 ± 4.3	-7.514	< .001	1.771	0.068	.795
	CG (n = 16)	16.2 ± 4.2	14.3 ± 3.2	-5.302	< .001	1.326
Body fat percentage (%)	PSG (n = 18)	22.0 ± 5.6	19.8 ± 5.7	-7.598	< .001	1.791	0.023	.879
	CG (n = 16)	22.1 ± 4.9	20.0 ± 3.9	-5.348	< .001	1.337
Skeletal muscle (kg)	PSG (n = 18)	32.2 ± 2.1	32.2 ± 2.3	0.000	1.000		0.737	.397
	CG (n = 16)	32.0 ± 1.8	32.1 ± 1.8	1.100	.289
RMR (kcal)	PSG (n = 18)	1965.0 ± 160.2	2093.9 ± 223.6	2.283	.036	0.538	0.742	.395
	CG (n = 16)	2006.3 ± 215.3	2069.4 ± 188.2	1.255	.229

Values are Mean ± Standard deviation.

RMR, resting metabolic rate; PSG, protein supplement group; CG, control group; Significance level at 0.05.

Figure 2. Changes in hepatic fat content from pre- to posttest. ***p < .001, **p < .01 significant difference within group.

Figure 3. Changes in hepatic fat content from pre- to mid-test. *p < .05 significant difference within group.

Table 3. Liver enzymes and lipid profile.

	Group	Pre	Post	Paired t-test			Repeated ANOVA
				t	p	ES	F (T×G)	p
AST (U/L)	PSG (n = 18)	22.4 ± 5.4	17.2 ± 3.3	-4.573	< .001	1.078	4.687	.038
	CG (n = 16)	19.2 ± 7.1	19.0 ± 7.2	-0.090	.929
ALT (U/L)	PSG (n = 18)	27.1 ± 16.0	16.0 ± 6.5	-3.638	.002	0.858	2.382	.230
	CG (n = 16)	22.6 ± 14.1	20.3 ± 17.2	-0.482	.637
TC (㎎/dl)	PSG (n = 18)	188.5 ± 23.2	150.8 ± 24.9	-11.256	< .001	2.653	1.696	.282
	CG (n = 16)	193.3 ± 23.8	164.1 ± 31.3	-4.921	< .001	1.230
LDL-C (㎎/dl)	PSG (n = 18)	110.7 ± 27.0	84.2 ± 25.7	-7.349	< .001	1.732	8.367	.978
	CG (n = 16)	119.2 ± 21.3	94.2 ± 28.2	-4.799	< .001	1.000
HDL-C (㎎/dl)	PSG (n = 18)	57.9 ± 10.3	51.7 ± 6.0	-4.064	.001	0.958	3.413	.074
	CG (n = 18)	55.1 ± 6.7	52.9 ± 4.4	-1.404	.181
TG (㎎/dl)	PSG (n = 16)	84.1 ± 19.0	75.1 ± 25.9	-1.142	.271		0.000	.987
	CG (n = 16)	93.8 ± 30.1	84.6 ± 32.4	-1.106	.286

Values are presented as mean ± standard deviation.

ANOVA, analysis of variance; T×G, time-by-group interactions; ES, effect size; AST, aspartate transaminase; ALT, alanine aminotransferase; TC, total cholesterol; LDL-C, low density lipoprotein cholesterol; HDL-C, high density lipoprotein cholesterol; TG, triglyceride; PSG, protein supplement group; CG, control group; Significance level at 0.05.