The mailing, which goes out next week through Proximity London, looks like a packet of pasta with text on it displayed to look like the labelling on a Freefrom product.
The pack includes a recipe using food from the Freefrom range, money-off vouchers for the brand and the opportunity to enter a competition to win a year's free gym membership.
The campaign is part of wider promotional activity involving in-store marketing, online promotions and TV ads.
Proximity has been working on Sainsbury's direct marketing since January 2001 and also works on the Sainsbury's to You home shopping brand.
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