I love having tamarind with salt and chilli powder but it makes me gain weight. even the next day. thought it was supposed to help weight loss.why?

See below: Tamarind has sugar in it so i suspect it is your problem...I had not heard that it was used for weight loss. I hope this helps.

Salt: The more salt you ingest the more fluid you will transiently retain, which will temporarily increase your weight. You will not have an appreciable weight change from day to day without some radical change in your diet or your exercise level. If you stick to a reasonable dietary intake and continue to exercise and minimize empty calorie intake (starch, sugar, etc.) you will not gain much weight.