I have a 13 year son who's father and I seperated when he was very young, and who's out of the picture now. Since then I've raised him myself, and he's an only child. Although he's now a teenager, we still have a close bond and enjoy spending time together, although he has friends of his own, some he's known since primary, other he made in high school.
My son had never been overweight until his final year of primary, when I noticed he was putting on a bit of weight. I had given him a bit more freedom, mainly in preperation for high school, and every so often he and his mates would go to the chippy or McDonalds to get something to eat. He started hanging out with friends outside of school more often, meaning more opportunities for snacks etc. By the start of high school, he had a little bit of a tummy.
I was probably a bit in denial at first, but I had a nephew who went through a bit of a chubby phase at that age and who's now a slim lad, so I assumed that would happen to him. But as he started high school, the weight gain accelerated. There wasn't any way of denying it, my son was getting fat. He was spending even more time with friends outside of school, and I found it difficult to control what he was eating. I cook healthy dinners at home, and only the occasional takeaway.
By his second year, you could really tell he had put on weight. He had a noticeably belly and was starting to grow breasts etc 
. I started worrying at this point. He gets the bus to and from school, and I suspected he was getting a single fair to school in the morning, then saving the rest of the money to buy crap. That was confirmed one day when he came home and I noticed he had chocolate all over his lips. I asked him what he had been eating, and he admitted he'd bought chocolate muffins from the local Tesco on his way home instead of getting the bus, and had tucked the rest in his bag for later.
He hadn't been seeing as much of his friends that year due to COVID, although they still met up outside and still my son continued to eat and eat. It's easy to see me as a lazy mother, but junk food is cheap. For example, the chocolate muffins he got from Tesco were 4 for £1.00, and they were about 300 calories each! On top of him eating god knows what when he's with friends, I truly am at a loss. I don't feel it's realistic to expect me to monitor my son 24/7 when he's with friends, or to restrict him from going out at all at his age.
He's recently started third year, and he's even fatter now than he was in second year. He's truly a big lad now, it's hard to believe he's the same boy looking back at photos from three years ago. I feel like crying honestly . He's a truly happy kid, I can't see any emotional issues at all, he enjoys school, has a good group of friends, none of whom are overweight themselves. Trying to gently discuss the issue with him basically results in him shrugging and saying he's comfortable with who he is. He says he jokes about his own weight more than his friends, and seems to be using it as comic relief.
Although he is obviously unfit at his size, he doesn't have any major health issues, yet. He just doesn't seem to see the severity of the issue. If anything, I would say he even enjoys being fat, and has no intention of losing weight. He has no interest in playing sport, although to be fair he never had any interest to begin with. Exercising more would at least keep his weight down a bit. I feel terrible, and feel I am going to have to put my foot down finally, but how?