Always tired and gassy after eating, is it the mamak food or something serious?

From my experience, that heavy sleepy feeling after nasi kandar is partly just the big carb-and-oil load, your body works hard to digest. When I cut down the super oily mamak dinners and stopped eating so late at night, the bloating improved a lot. Try smaller portions, more veg, drink water instead of teh tarik, and don't lie down straight after eating. That said, cramps and persistent bloating can also be things like gastritis, food intolerance or IBS, which lifestyle alone won't fix. If it keeps happening for a few weeks or you get pain, weight loss or other symptoms, please see a doctor and get it checked properly, don't self-diagnose.

I had almost the same thing and turned out I was slightly lactose intolerant, so all the milky teh tarik and certain gravies were triggering it. What helped me was keeping a simple food diary for two weeks, writing what I ate and how I felt after. You might spot a pattern, could be dairy, could be too much fried stuff, could be eating too fast. Also eating late and then sleeping makes bloating worse. But please, if you get real cramps, blood, or it doesn't improve, go see a GP, it's cheap at a klinik and better safe than sorry. Don't let mamak habit mask something that needs treatment.