Using \textsc and \textbf with titlesec

Question

I would like to have my section titles in bold and small caps, but they do not seem to work.

\documentclass[12pt,a4paper]{article}
\usepackage[
    left = 2cm, 
    right = 2.5cm, 
    top = 1.5cm, 
    bottom = 2cm
]{geometry}
\usepackage{microtype}
\usepackage{titlesec}
\usepackage{fancyhdr}
\titleformat{\section}{\Large\sc\bfseries}{}{0cm}{}[\titlerule]
\titleformat{\subsection}[runin]{\bfseries\sc}{}{0cm}{}[ --]
\titleformat{\subsubsection}{\large\bfseries\sc}{}{0cm}{}
\renewcommand{\labelitemi}{--}
\newcommand{\tabitem}{\makebox[0pt][r]{--}}
%Manipulation of headers and footers
\pagestyle{fancy}
%Clear fields
\fancyhf{}
%Page numbering in footer
\fancyfoot[C]{\thepage}
%Separation line header and footer
\renewcommand{\footrulewidth}{0.4pt}
\renewcommand{\headrulewidth}{0pt}
\begin{document}
\thispagestyle{fancy}
\begin{center}
\Huge \textbf{\textsc{Eating\hspace{0.5cm}Foods}}
\end{center}
\section{How to eat food}
Food is important
\subsection{Using hands}
Most versatile
\subsection{using chopsticks}
Requires practice
\subsection{using spoons}
Kind of a middle ground
\subsubsection{Types of spoons}
There are many types of spoons
\end{document}

Currently, all titles only come in bold font or small caps depending on their order of appearance in the \titleformat argument.

Answer 1

As Alan Munn mentioned in the comments, you need to use \scshape rather than the plain TeX \sc (which cannot be combined with other formatting). You will then get the warning:

LaTeX Font Warning: Font shape `OT1/cmr/bx/sc' undefined

OT1 is the original 7-bit TeX encoding from the ’80s (back when network hardware would often use the eighth bit for error correction and mangle 8-bit data). It’s still the default output encoding in PDFTeX (although the default input encoding is now UTF-8). The default font, Computer Modern Roman (cmr), doesn’t define a bold extended (bx) small-caps (sc) face in OT1.

In PDFTeX, you can fix this by switching to a slightly-less-obsolete 8-bit encoding from the ’90s.

\usepackage[T1]{fontenc}

If you can, I would recommend changing to LuaLaTeX and modern fonts. The default font in LuaLaTeX does not come in bold small-caps either, but you can switch to a clone that does, such as New Computer Modern. (The settings I used will get you a slightly-heavier font, but you can tweak this if you want with a package option.)

\documentclass[12pt,a4paper]{article}
\usepackage{iftex}
\iftutex
  \usepackage{newcomputermodern}
\else
  \usepackage[T1]{fontenc}
\fi
\usepackage[
    left = 2cm, 
    right = 2.5cm, 
    top = 1.5cm, 
    bottom = 2cm
]{geometry}
\usepackage{microtype}
\usepackage{titlesec}
\usepackage{fancyhdr}
\titleformat{\section}{\Large\scshape\bfseries}{}{0cm}{}[\titlerule]
\titleformat{\subsection}[runin]{\bfseries\scshape}{}{0cm}{}[ --]
\titleformat{\subsubsection}{\large\bfseries\scshape}{}{0cm}{}
\renewcommand{\labelitemi}{--}
\newcommand{\tabitem}{\makebox[0pt][r]{--}}
%Manipulation of headers and footers
\pagestyle{fancy}
%Clear fields
\fancyhf{}
%Page numbering in footer
\fancyfoot[C]{\thepage}
%Separation line header and footer
\renewcommand{\footrulewidth}{0.4pt}
\renewcommand{\headrulewidth}{0pt}
\begin{document}
\thispagestyle{fancy}
\begin{center}
\Huge \textbf{\textsc{Eating\hspace{0.5cm}Foods}}
\end{center}
\section{How to eat food}
Food is important
\subsection{Using hands}
Most versatile
\subsection{using chopsticks}
Requires practice
\subsection{using spoons}
Kind of a middle ground
\subsubsection{Types of spoons}
There are many types of spoons
\end{document}