Participants and compliance
Out of the 66 participants included, 29 were female and 37 were male with a mean age of 70 years [median: 69 years; range: 65–80 years]. Baseline subject characteristics for the five different intervention groups are presented in Table Subject characteristics baselineMeans ± SDThe CARB group protein intake did not change (− 4.9 g, 95% CI [− 15.8;6.1]). COLL,WHEY, LITW and HRTW groups significantly increased their protein intake by 29.0 g (95% CI [21.1;36.8]), 25.7 g (95% CI [15.6;35.8]), 23.9 g (95% CI [15.2;32.5]) and 26.7 g (95% CI [18.9;34.5]) corresponding to an approximal increase in total protein intake from ~ 1.1–1.5 g kgFor an overview, see CONSORT diagram in supplemental 5.