Weight loss abroad

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Hi all, just looking for some general advice

I'm currently travelling around South America for the next three months. Right now I'm in Colombia and I'm going on to Peru, Bolivia and Argentina. I am finding it alright in terms of exercise as I am naturally walking around a lot but eating is a bit more of a struggle - I am on a very tight budget so I am not eating at restaurants much but I am definetly finding it difficult to come up with varied, filling things to eat.

Also, I believe I've lost weight since coming out here - any South American efficionados know where I might be able to go to weigh myself?

Looking for any tips (about anything!) from anyone who is familiar with that area of the world or who has done similar length trips

Cheers guys