A study of some families in Saudi demonstrates that some Muslims gain weight during Ramadan. While most Muslims improve their metbolic profile, improve their insulin resistance, improve their lipid panel and reduce inflammation, and lose weight. It turns out some do the opposite.
Binge eating or gorging in the evening is what leads to weight gain, as well as the choice of food. Some Muslims eat fattier foods and much more dessert and sweets than usual. Avoid simple carbs, eat smaller, more frequent meals and you should be able to ward off the weight gain and worsening of your lipid panel and metabolic markers.
Read the full study:
You can click on the PDF link to read the entire study.