If you eat a healthy diet during the intermittent fasting, body fat can be permanently reduced. With intermittent fasting, there is no reduction in energy requirements, as with other diets. On average, you eat fewer calories than before, but the metabolic hormones still react differently than with other diets due to the different distribution of meals. So, if you eat a healthy diet and do not consume excessive calories after the fasting, there is no yo-yo effect after intermittent fasting.