\setupbodyfont [pagella]

\starttext
    \startMPcode
        addto currentpicture also "FooBar effe" infont defaultfont ; % default scale
        label("FooBar effe", origin) shifted (0,-06mm) ;
        draw btex FooBar effe etex   shifted (0,-12mm) ;
        draw textext("FooBar effe")  shifted (0,-18mm) ;
        draw boundingbox currentpicture ;
    \stopMPcode

    \switchtobodyfont [10pt]

    \startMPcode
        addto currentpicture also "FooBar effe" infont defaultfont ; % default scale
        label("FooBar effe", origin) shifted (0,-06mm) ;
        draw btex FooBar effe etex   shifted (0,-12mm) ;
        draw textext("FooBar effe")  shifted (0,-18mm) ;
        draw boundingbox currentpicture ;
    \stopMPcode

    \definefontsynonym[MetafunDefault][Bold*default]

    \startMPcode
        addto currentpicture also "FooBar effe" infont defaultfont ; % default scale
        label("FooBar effe", origin) shifted (0,-06mm) ;
        draw btex FooBar effe etex   shifted (0,-12mm) ;
        draw textext("FooBar effe")  shifted (0,-18mm) ;
        draw boundingbox currentpicture ;
    \stopMPcode

\stoptext
