How to eat less/correct at night

I eat lunch at 1 - leave office at 7 and reach home at 7.15,
sleep at 10- Need to find way to sleep with minimalistic food.
Purpose is to sleep well, loose wt, detoxify my body with lesser food at night , and have absolute quick bowel movement in the...

morning. I am veg and would want something that can be cooked at my office (have microwave there) or at home - have a helping hand.
Looking for a regime that is sustainable

eat a really thick soup. they're quite filling. they may be on the fatty side, but you dont eat too much of it, because of how quickly you'll feel full.

Only eat breakfast at home. If you feel like you need a snack when you get home from work, eat fruit. Cook and freeze your dinners (healthier option) to take with you to work every Sunday, or buy the frozen meals.