In Egypt I heard this conversation more than once:

- You’ve lost a lot of weight! How did you do it?

- Through constant dhikr.

Now to me, this sounded really silly, but after a while I came to realize that it was I who was silly. There are at least two ways that you can lose weight from dhikr, and here they are in the order that I read about them/realized them.

Safiyy al-Din Ahmad b. Muhammad al-Dajani al-Qushashi says in as-Simt al-Majid, in the section about dhikr:

Al-Jurayri said, “One of our companions was a man who would constantly say ‘Allah, Allah.’ One day a tree branch fell on his head, causing a skull fracture, and he bled, so the blood formed the words ‘Allah, Allah’ on the floor” . For dhikr is a fire that leaves nothing and spares nothing (Qur’an 74:28), if it enters a house it says “Me, and nothing else!” which is one of the meanings of “La Ilaha Illa Allah“; so if it finds in it wood it burns it, making it fire, and if what’s there is darkness it would be light and illuminate it, and if what’s there is light it would be light upon light (Q 24:35). And dhikr removes from the body all the malignant or harmful excesses that result from overeating and from eating food that is haram; as for all that comes from halal food it does not touch it. And if all the malignant parts are burned and only the pure are left, you would hear dhikr from every part of your body, as if it were a trumpet blow. (pg 11-12)

So you see, this great sufi Master is explaining how dhikr, just like fire, burns all that which is bad (khabeeth) in the body, such as what is caused by eating too much, and especially all that which is haram food. Haram food can be forbidden food like alcohol and pork, or it could be food that was obtained in a forbidden manner or bought with money that was made from a non-halal way, even if it was the person giving you the money who obtained it in a non-halal way, not you (so long as you were aware of that). So as you can see, it is likely that all of us have eaten something that in one way or another was haram and the fire of dhikr burns it better than any fat-burning supplement.

Of course the other way is that dhikr helps you subdue and control your desires, making you able to stop eating as much. All types of dhikr probably do this, but perhaps the most effective is Allah’s name al-Qahhar.

Here is an explanation of the Name and its benefits from Sheikh Muzaffer Ozak al-Jerrahi’s Irshad: Wisdom of a Sufi Master:

AL-QAHHAR: The subduer. He who dominates all things, and prevails upon them to do whatever He wills.

YA QAHHARU: O Subduer! This invocation helps one to subdue the desires of the flesh, ridding the heart of wordly attachment and leading to inner peace. The recitation of this Name also affords protection against cruel injustice.

Perhaps another useful name is al-Malik (The King), because as Queen of Sheba is quoted in the Quran, when kings enter a town they ruin it and subjugate the noblest of its people. Ibn Arabi understood from this verse an analogy to the light of Allah entering the human heart and leaving there nothing else, and subjugating the nafs. Al-Qushashi says the same thing above, but comparing the heart to a house instead. In any case, with constant dhikr you can control your desires and your food, your body becomes illumined, and you burn all the excesses that have formed from haram food.