A motorist who caused the death of a learner driver in a head-on smash claimed she had blacked out at the wheel because of her low-calorie diet.

Patricia Aitken was ordered to carry out 240 hours community service and was banned from the road for five years after the collision that killed Suzanne Harkness.

The 55-year-old teaching assistant had initially denied the charge, claiming her low-calorie diet caused her to black out moments before the smash.

Ms Harkness, 22, from Galashiels, was on a driving lesson at the time and seriously injured her driving instructor.

At Jedburgh Sheriff Court on Friday Aitken changed her plea to guilty after the Crown produced an expert report that dismissed the suggestion that the diet could have caused the loss of conciousness or fainting at the wheel.

Sheriff Donald Corke said he had seriously considered custody for the offence as "the circumstances had never been properly explained". He added that the crash has "devastating consequences" for Ms Harkness’ family.

The sheriff decided to follow the recommendation made in background reports to impose the alternative to custody.

Aitken pled guilty to driving carelessly and causing her Volkswagen Passat to go onto the opposite carriageway of the A6091 road near her home in Melrose, on August 26, 2009.

Her car collided with the Citreon being driven by officer worker Ms Harkness, which killed her and left her instructor James Egan seriously injured.