Gaining and losing weight is a matter of simple physics. Perhaps an understanding of basic scientific principles is what should be learned.
Why do people eat more calories than they need? It's presumably a complex interaction of physiological, social, emotional, and, yes, market factors, with different factors of different importance given the situation.
I can recognise this even though my weight would have been considered normal 50 years ago.
When Mt. Dew Kickstart came out, I thought I would try it. I had one and it was decent so I got four or five. Went through those and then when I was done, I could feel my body craving it, even though I was only drinking one can a day. I thought it was weird and went back to read the ingredients.
Sucralose was the prime suspect. I did some more research and found out:
Sucralose is about 320 to 1,000 times sweeter than sucrose, three times as sweet as both aspartame and acesulfame potassium, and twice as sweet as sodium saccharin.
https://en.wikipedia.org/wiki/Sucralose
I knew Sucralose was much sweeter than sugar, but was alarmed to find out by how much. It was scary to feel my body craving it and knew I had to stop drinking it. I could've easily put down three or four a day if I didn't stop when I did.
Sucralose also has no nutritional value, so I'm not sure why you're body would crave it beyond you just liking sweet tasting drinks.
Mother and father are working longer hours with no set office hours, the kids are constantly on the go with athletics, school clubs or after school programs. Nobody has the time to really take the time and prepare a decent meal. Heavily processed food just became a substitute for the time it took to prepare a real meal. Fast food then became a crutch for families on the go even replacing the heavily processed food that replaced the real food people used to prepare.
The end result is kids and parents both eating poorly, heavily stressed at school and at work. They eat poorly, they don't get enough exercise and now they gain weight and other issues that affect their health.
As many people have pointed out in various other threads, in the 50's and 60's people hardly ever ate out, the family dinner was a big deal and most families ate at the same time every day, had set schedules and the kids exercised a lot more (whatever happened to recess??) by playing games, athletics, and using their imaginations.
It's really hard to disentangle plausible causes. But I agree, something must have changed, something that makes this problem correlate with "westernization" and technological advancements of societies.
I think some people just have their internal "hunger" thermostat set wrong- whether it's hormonal or psychological or whatever. Other people have it set more correctly so by and large, "willpower" doesn't come into it.
I don't need willpower to stop myself overconsuming water, but if I was thirsty literally all the time, I'd drink gallons.
The question is, how does one generally control this?
There appear to be a multiple biological systems, psychological, economic, health, societal, cultural, and evolutionary factors at play which influence how much/how often/what a person eats, how they metabolize what they eat, how much they exercise, etc.
You’re ignoring all that if you try to treat it as matter of “simple physics”. You’re effectively denying the problem by vastly oversimplifying it.
How does one generally control becoming addicted to any addictive substance? Generally, moderation or abstinence, particularly for those susceptible to addiction.
Food addiction is not so different from drug or alcohol addiction, though food has a much shorter 'high' associated with it than nearly any drug. And food addiction is societally acceptable, whereas drug addicts are generally looked down upon.
If external factors are fucking with your thermostat, it's going to be more challenging to reach a target temperature.
There are complex feedback systems controlling hunger and physical activity. In one study it was found that when participants were fed extra calories, only some of them gained weight. Some of them burned them off by unconsciously fidgeting more, others didn't. People can burn 350 cals per day from fidgeting.
On the flipside, excercising makes people hungrier.
Of course, a bad food environment is not an excuse to not lose weight, but it's also not an excuse for the government and society to do nothing at all and blame it all on the individuals.