Hi, I Am 29 Yrß Old Female. Since 2-3 Months

Hi, I am 29 yrß old female. Since 2-3 months I am facing this issue of going for excretion after anything I eat.be it even minor handful of peanuts or biscuits. That is not the condition with processed food even if I m eating fruits it is happening. I m facing excessive gas flatulence my tummy soze has increased drastically and I m.gaining weight even if I m not eating much and doing some work out as well.stools are normal and not loose. Want to.mention I have vit d and calcium deficiency as well n taking shellcal and multivitamins daily. Also I work in night shifts bt take avg 7-8 hrs of sleep.I take brkfst at 6:30 then sandwich at 10 am and then proper meal at 8 PM.