That depends on how many calories you are taking in. If you eat 5k calories a day and suddenly fast 1 day a week you aren't going to lose weight you will just stop gaining as quickly.
"Turbocharge weight loss" means that there is existing weight loss to turbocharge. If you are losing weight, reduce weekly calorie intake by 14% and change nothing else, I think the description is accurate independent of the pre-existing intake level.