But I haven’t smoked in months (Image: Rex Features)

CANNABIS smokers beware: stress or dieting might trigger “reintoxication”, resulting in a positive drug test long after you last used the drug.

The main psychoactive ingredient of cannabis is tetrahydrocannabinol (THC), and once in the body it is readily absorbed into fat cells. Over the next few days it slowly diffuses back into the blood. Since THC is taken up by fat more readily than it diffuses out, continual intake means some THC can remain in the fat cells.

It has been suggested that stored THC can be released at a …