Recent filings for the restaurant, which was opened by Heston Blumenthal in 1995, show pre-tax profits more than doubled to £746,741 in the 12 months to 26 May 2019, up from £297,788 the previous year.
Turnover rose from £6.7m to £7.3m, while EBITDA was up from £900,000 to £1.3m.
The Fat Duck only returned to profit in 2017 after posting losses following a brief relocation to Australia and a £2.5m revamp of its Bray home.
Director Peter Moody writes in the accounts that management is following a strategy to “foster the evolution of the restaurant”.
The Fat Duck has held three Michelin stars since 2004 and was ranked number one in the World’s 50 Best Restaurants list in 2005.
The restaurant ran its first Christmas menu, a £375 “edible adventure” celebrating the Christmas tree, throughout November and December last year.
But Moody said margins were impacted by the uncertain impact of Brexit, the rising National Living Wage and inflation in supplier costs.
He added that the restaurant continues to work on “efficiency programmes” to offset these issues.
“These external factors continue to make the economic and trading environment challenging for the company," he said.