A spokesman said Unilever was looking at a number of options including sharing its facilities with other manufacturers and outsourcing parts of production processes to other sites.
He said the review, due to be completed early next year, was focused on the Lowestoft plant which produces red meat, poultry, frozen vegetables and potato products. Grimsby, which produces frozen meals, is also affected.
However, the Hull factory which produces fish and peas, is unlikely to be directly affected.
The company announced a major review of its supply chain for Birds Eye in the UK at the start of November.