The nutrition specialists, based in Wales, are already suppliers to the Welsh Rugby Union, last year's English Premier League Champions Leicester City FC and the Football Association of Wales.
The products supplied to the team will include PAS’s ‘Real Deal’ protein bars, Excel Gels, and its electrolyte drink with added BCAAs, Pro Zero Cola.
"We are delighted to be teaming up with the British and Irish Lions and to become an Official Supplier. The Lions have unrivalled history, tradition and standing in world rugby and it is a very proud day for all of us at PAS," said director and nutritionist, Jon Williams.
The products supplied to the team will aid in both recovery and performance.
The range also includes bespoke recovery shakes, immunity products and a night time recharge sleep formula.
Paul Stridgeon, head of strength and condition for the British and Irish Lions, said: "PAS have also been able to formulate and make products, which will help with our specific needs on tour to New Zealand.
"These will make up a valuable part of our performance protocols".
PAS was founded in 2006 by Jon Williams and former Olympic sprinter Darren Campbell.