The new Burger King fries which contain 30% less fat than their regular fries and are called 'satisfries;. The batter they are using won't absorb as much into the potato which will make the difference in nutritional value. They will also be crinkle cut so that staff can work out the difference between those and the regular ones.
Is this however going to make much difference? Do you think people are more likely to go for the diet option if they are in a fast food restaurant??
Reference - Daily Mail - http://www.dailymail.co.uk/health/article-2572940/Burger-King-launches-diet-chips-target-health-conscious-customers-Satisfries-30-fat.html