Is it wrong to leave food on plate?

so i used to eat quite a bit but ever since i decided to lead a healthy lifestyle i have cut down on my intake of food. I mean i dont starve, if im hungry i'll defi eat but it seems like now restaurant portions are just too big for me! i chew my food slowly so prob by the end of the meal i'll still have 1/4 of my food left. My mum kept commenting that i should just eat the food and she doesn't believe that im genuinely full. Its kind of irritating cause i dont like the feeling of bloatedness. I've only started this healthy living thing this yr so you can probably say its a drastic change? What should i do to make her trust me that im really full?