I think the rise in obesity has a few reasons.
I'll start with the 'lazy reason'. I have read numerous studies showing that the obesity rates in the modern day are way higher than 'back in the day', and most people will be confused. Nowadays there are gyms that are affordable and everywhere, home gym equipment that is affordable, healthy food is not actually expensive, personal trainers all over, and so on. Compare that to 'back in the day', there were hardly any gyms around, and the ones that were around were expensive to go to, home gym equipment just didn't really exist, and overall the 'health and fitness' industry was nothing compared to today. So, how on earth can there be a much higher obesity rate? That's where my first reason comes in. The modern day is surrounded by technology that, yes, makes our lives easier, but also makes us lazier. In the old days, all the factories (car factories for example) had humans doing nearly all of the work, which was hard labor! that kept people fit and strong. Now, most of it is controlled by machines.
You can pop online and do all of your shopping and get it delivered to your house, instead of going out and doing it for yourself. Go back a fair few years and education was A LOT harder - whereas today every school has computers and calculators and other tech. (studies have shown that a percentage of modern day people cant do fairly basic math and spell certain words, because they rely on calculators and spell check). I could name a lot more other things that tech has made our lives 'easier' but made us lazy. And because of all of this, people have become more lazy, and that's why all these 'fad diets' and pieces of fitness equipment that promises to lose a ton of weight with doing minimal effort sell like crazy! because people think - 'I can lose all my fat by doing nothing! wahoo!'. What is easier - ordering a takeaway or cooking a fresh healthy meal? the takeaway, and that is why people do it, because they cannot be bothered to make a meal themselves - they would rather sit on the couch and wait 20 mins for it to be delivered. Certain companies have earned a fortune because of this - diet companies that 'deliver food straight to your door!'. This is the same process as ordering a takeaway, and its because of people being lazy. I think i'll end it there.
Another reason can be personal situations - where they live, their family etc. If you get brought up in a family that is overweight, your most likely to become overweight too. If your going though depression, that can lead to weight gain. The amount of children that get bullied in schools these days is ridiculous, and that can cause weight gain. They get bullied at school, come home and find 'comfort' in food - food that is fatty, sugary and just bad for you.
There is a lack of education about being healthy. Schools don't really cover it, and those that do, its kind of meaningless. There are some schools that do talk about it and try and educate children, but then what do they serve in the cafeteria? fried food, battered food, fatty food in general. So kids will come out of a class after being spoken to about health, diet, fitness etc, then go to lunch and find the only food that is available is unhealthy food - stupid if you ask me. Much loved cook, Jamie Oliver, tried to help this situation, and to a certain degree, he did, but a lot of schools just couldn't be bothered as it would cost them a bit more cash to serve healthy food. (Big whoop - you would be making a real difference!)
Lastly, and this can be a bit controversial, but I have read it a fair few times now, and I believe it to a certain degree. There is no 'punishment' for someone being obese. They can get free obesity surgery on the NHS, they don't pay any more money for bigger clothing - which, I believe, whether you are obese or tanked with muscle, if you need bigger clothing, in a way, its fair that you have to pay more. (but there are downsides to that too!). They don't get charged extra money from airlines (even though one airline is trialing it) which personally was annoying for me when I flew home from Australia. I had 5kg extra baggage and got charged, and a woman in front of me who must have weighed about 25 stone, didn't pay anything, even though my weight and baggage weight was way under just her body weight. There is no penalty anywhere really, so obese people don't get it straight in their face - 'Lose weight!'. They get told about heart disease, heart attacks, lung problems and so on, but a lot of them kind of just....wave it off. If people knew that they would have to pay more for things like plane seats, because of being obese, I am sure that many obese people would get going with losing weight, because they wouldn't want to pay more and be embarrassed at the check in when they get told they have to pay more because of their weight.
There was a big article in a newspaper a couple of years ago that soon spread over the radio and I think TV. A woman was obese and got told by her GP that she would need a gastric band, so she pretty much went to book one in, only to find out that she was 3 stone under the weight limit to actually get one (free from the NHS!). So instead of her going away and losing weight as she couldn't have the surgery, (she even openly admitted this in the interviews) she went and deliberately gained those 3 extra stone that she needed in order to have free surgery, and got it! To me, that is just disgraceful and lazy.
Well, they aren't all the reasons for obesity, and I am sure many people out there will disagree with them. But they are my views, and also views of many other people. Thank you for reading.