I feel there's aorta of truth in this assertion because looking at it from nutritional perspective, by engaging in fasting, which is also a planned way of skipping meals, you would notice that the exercise makes one to be very light and hungry. This lightness can be attributed to the body cleansing itself by removing toxins deposited in it over time.
Nutritionally, skipping meals(fasting) is advisable, because during this period not would the body rid it off toxins, but it also ensure that the stored glucose in the liver is used up, so that the body can once again cleanse itself from stored glucose, thereby allowing it to free up the organ for more fresh storage.
Undoubtedly, I presume this process is highly connected to the body cleansing itself via skipping meals.