Thai food doesn’t contain any trans fat unless the condiments or sauces contain it, which is usually not the case with traditional Thai food.
Trans fat is added to products such as margarine in order to give the products a longer shelf life. The typical sauces in Thai food don’t contain trans fat, but you must always check the ingredients labels to be sure.
If you see hydrogenated oils in the list of ingredients and the product is also high in fat, that it most likely contains trans fat. The hydrogenated oil is a dead giveaway for trans fat.
Some soy sauces mask the presence of MSG by labeling it as a flavor enhancer. Usually, though, you are safe from trans fats in Thai cuisine.
You have to worry about baked goods having trans fat in them, so be wary of Thai pastries and cakes. But with the main Thai food dishes, I would be less concerned.