I think you have a misconception about metabolism. During Water Fast the metabolism is lowered in initial stages of the fast and then stabilizes. After the fast the metabolism will return to its normal level if you eat correctly, feeding your body with natural foods with good nutrition. Eat as per hunger afterwards to avoid gaining weight and keeping the body clean.

"Re-feeding" is another misconception people have. Re-feeding is life long and not a period where you eat good nutritive foods and then go back to eating the way you ate before fasting. However when you do start eating after a fast you have to gradually increase your food intake, otherwise you do gain weight very fast and body becomes sluggish.

During your fast you may walk everyday, but resting and drinking as per thirst is important.

Happy fasting.

Archus