Fast metabolism fix?
I'm going to preface this by saying I've tried everything,and I mean EVERYTHING to gain weight naturally. I've sometimes counted 3-4k calories in one day,I've done weight lifting for a bit and I've gained like barely 5kgs from it. My starting weight was 45kg at 165cm height,I'm now around 50kg but I want to get to at least 55-60kg. I've always been told I have a genetically fast metabolism,but it's fast to the point of nothing ever staying in my body. I have problems with iron because of it,but that's easily fixable with diet and supplements. I've also been told it's because of my age (18F). I'm really lost on what to take to slow my metabolism even by a little (I've read about antihistamines,antidepressants,even prenatal supplements) and doctors usually write me off as lucky for being skinny. Please help !