The 16-strong group plans to use the funds to develop its existing sites and target new suburban locations.
Gusto was formed by Living Ventures Group, the company behind The Alchemist and Manchester House, in 2005 and now employs more than 600 staff.
It was backed by Palatine Private Equity in a management buyout in 2014, and saw turnover rise 21% to £23m in the year to March 2016.
The company recently opened in West Bridgford, near Nottingham, and has already identified sites in Yorkshire, the Midlands and the South.
“With the ongoing support from Palatine and a great Gusto team in place, we will continue to build our position as a national brand,” says Sue Crimes, managing director of Gusto.
The company launched a £1m site in Birmingham last year and is aiming to expand to 26 sites in the next four years.