Effect of a high protein diet and/or resistance exercise on the preservation of fat free mass during weight loss in overweight and obese older adults: a randomized controlled trial

Table 3 Change in outcome measures at 10 weeks of intervention with protein and exercise effects^a

	Control	Protein	Exercise	Protein + Exercise	Protein effect		Exercise effect		Protein * Exercise interaction
	(n = 22)	(n = 21)	(n = 25)	(n = 32)	Beta (95% CI)^b	P ^c	Beta (95% CI)^b	P ^c	Beta (95% CI)^d	P ^e
Body weight, kg	−1.7 ± 1.8*	−2.1 ± 3.6*	−2.6 ± 2.9*	−2.0 ± 2.2*	+0.1 (–0.7;1.0)	0.763	−0.3 (−1.1;0.5)	0.472	NS
BMI, kg/m²	−0.6 ± 0.6*	−0.8 ± 1.1*	−1.0 ± 1.0*	−0.9 ± 0.9*	−0.0 (−0.3;0.3)	0.924	−0.2 (−0.5;0.1)	0.213	NS
Waist circumference, cm	−3 ± 4*	−3 ± 4*	−4 ± 4*	−3 ± 3*^f	+0.3 (−0.9;1.4)	0.673	−0.4 (−1.6;0.8)	0.555	NS
Fat mass, kg	−1.5 ± 2.5*^g	−2.1 ± 3.4*	−2.8 ± 3.7*	−2.6 ± 2.4*	−0.0 (−1.0;0.9)	0.946	−0.8 (−1.7;0.2)	0.124	NS
Fat percentage, %	−1.0 ± 2.1*^g	−1.3 ± 2.2*	−1.9 ± 3.3*	−2.1 ± 2.0*	−0.1 (−0.9;0.6)	0.736	−0.8 (−1.6;−0.0)	0.048	NS
Fat free mass, kg	−0.0 ± 1.4^g	0.0 ± 1.5	+0.2 ± 2.3	+0.6 ± 1.3*	+0.1 (−0.4;0.7)	0.666	+0.3 (−0.2;0.9)	0.233	NS
Handgrip strength, kg^h	+1.8 ± 6.6	−1.7 ± 6.5	−1.8 ± 11.6	+2.0 ± 6.0	−2.2 (−6.4;2.1)	0.311	−1.9 (−6.0;2.1)	0.346	6.2 (0.6;11.8)	0.030
4-m gait speed, m/s	+0.13 ± 0.24*	+0.08 ± 0.26	+0.08 ± 0.13*ⁱ	+0.20 ± 0.24*	−0.04 (−0.15;0.06)	0.440	−0.04 (−0.14;0.06)	0.476	0.14 (0.00;0.28)	0.045
400-m gait speed, m/s	+0.04 ± 0.15	+0.07 ± 0.10*	+0.07 ± 0.07*ⁱ	+0.08 ± 0.15*	+0.02 (−0.03;0.06)	0.445	+0.01 (−0.03;0.06)	0.554	NS
Repeated chair stands, s	−1.6 ± 2.1*	−1.6 ± 1.7*	−1.0 ± 2.7ⁱ	−1.4 ± 2.7*	−0.1 (−0.9;0.6)	0.703	−0.2 (−0.9;0.6)	0.643	NS

^aData represent means ± SD using last observations carried forward; ^bEstimate of protein or exercise effect at week 10 using mixed linear model including time, sex, protein (high/normal), exercise (yes/no) and baseline value; ^cSignificance level of estimate of protein or exercise effect at week 10 using mixed linear model; ^d Estimate of interaction effect of protein*exercise at week 10 using mixed linear model including time, sex, protein (high/normal), exercise (yes/no), protein*exercise and baseline value only presented when the interaction effect was significant (P < 0.1). The effect of the combined protein-exercise intervention can be calculated by summating the beta’s of the protein effect, the exercise effect and the interaction protein*exercise effect; ^eSignificance level of the interaction effect of protein*exercise at week 10 using mixed linear model; ^f n = 31; ^g n = 21; ^hSum of maximum of left and right hand, n protein group = 20; ⁱ n = 24; ^* Significant mean change at week 10 within group using a paired t-test; NS not significant (P ≥ 0.1)

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