Dame Deirdre Hutton, FSA head, is expected to call on consumers in a speech to the National Federation of Women's Institutes on Britain's obesity epidemic to lobby the supermarket for clear front-of-pack nutritional information.
The criticism comes three months after Tesco was condemned by the Office of Fair Trading for its refusal to introduce the new system.
The traffic light system, which uses red, amber and green labels to describe high, medium and low levels of salt, fat and sugar in food, was rejected by Tesco in March, leading to condemnation by health campaigners.
Tesco claims that the FSA's system was too simplistic and has developed its own labels, which shows recommended guideline daily allowances instead.
In her speech today, Hutton will say: "You have to wonder why these companies are choosing to ignore the weight of evidence and not use traffic light colours."
Yesterday, Hutton praised Sainsbury's, Asda and Waitrose for adopting the traffic lights and said the Tesco labels were less clear.
Morrisons and five food companies -- Danone, Kellogg's, Kraft, Nestle and PepsiCo -- have also developed a rival system.
A Tesco spokesperson said: "We were the first supermarket to trial traffic lights. We found that many were unable to make use of them in their shopping habits, leading us to look at alternatives."
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