Just fukking eat less. It's literally that easy.
umm kinda of. only if you massively over eat every day of your life. other than that, eating less just slows down your metabolism and your body will only burn enough calories based on the calories that are put into it.
when you say eat less you have to be specific, he could only eat 2 big portions or eat 4 small portions a day. Everyone should consistently drink cold water/fluids because the coldness drops your core temp and your body burns calories while regulating your temperature (keeping you warm). I saw water/fluids because I never ever drink water, but I do drink tea, either green on black- not sweet tea either. no sugar and only sometimes a teaspoon of honey but its foolish to drink your calories especially if your trying to lose weight pop, milk, juice- fukk outta here with all that.
you have to move more, theres no secret around it.