What city do you live in? There is a huge array of healthy low calorie options near me all the way to pure vegetarian/vegan places.

There is a ridiculously strong correlation between sedentariness and obesity. We our more sedentary than ever before and then remote work/school increased it again.

I believe a person struggling with weight is basically determined in their childhood. Only in childhood will the body build new fat cells and the number of fat cells determines hormonal production of leptin and others which trigger hunger cues for the rest of life. Basically a fat child will permanently be hungrier for the rest of their life due to increased numbers of fat cells. If you’re a skinny and active kid you will permanently have an easier time to keep weight off. And before you blame food again sedentariness has increased among children immensely as well.

yet most fat adults were not fat children, though in another 30 years that will no longer be true; childhood obesity was rare until this millennium

Fat parents often have fat children. There’s a strong correlation.

yes, that is true, and we know several reasons for it, but it is irrelevant both to the narrow issue of whether fat cells produced in childhood derange your caloric intake regulatory homeostasis thereafter, and to the broader issue of why there's an obesity pandemic

It certainly was rarer but this was a known phenomenon occurring at least back in the 1960s

Off the top of my head I know there’s a speech of JFKs where he advocates for child health saying quote “there’s nothing more unfortunate than fat chubby children”

New York City

Various industry sources and think tanks (with various biases, including IfG, IEA, Czarnikow) suggest sugar consumption has fallen very significantly in the UK and Australia since 1970, without any apparent impact on obesity rates.

However, I can't find trustworthy original academic research on it, which makes it difficult to draw any firm conclusions. In any case, it doesn't appear that sugar consumption has risen dramatically in the last 50 years in the UK, yet obesity rates (and associated metabolic diseases) have continued to rise. Most research seems to suggest sugar is a marker of an unhealthy lifestyle rather than the cause, but the cause still seems to be essentially unknown. It is true that countries that eat very little sugar tend to have lower obesity rates, but that seems mainly to be because they are usually extremely poor.

In my opinion, there's more evidence that low fibre and easily digestible food is a bigger culprit than sugar, but the evidence is very poor quality on all sides.

there's also evidence that sugar consumption in the usa a century ago was already high, and the hadza famously eat mostly honey in july and august, so i think that while sugar is probably a contributor, it's probably not sufficient by itself

it would be pretty surprising to find that, say, propionate intake suppressing intestinal yeast growth was a major cause of the obesity pandemic. but it certainly seems to be something about industrial food manufacturing that goes beyond just caloric density and macronutrient balance, and additives seem like a promising place to look

i mean the village baker a century ago didn't put calcium propionate in his bread so it wouldn't get moldy, he just threw the moldy bread out

Obviously there could be many factors. I want to point out, though, that a caloric deficit is a marginal difference. That means small changes in the base calorie intake can lead to a many-fold increase in your caloric deficit.

As an example, let’s say you go from a healthy adult at 18 years old and 160 lbs, to an obese adult at 40 and 300 pounds. That’s 140 pounds over 22 years. If a pound of weight is gained after 3,500 excess calories, then this person only consumed roughly 60 extra calories a day. If they consumed only 20 excess calories a day, they would be 195. Overweight, but still relatively healthy. It doesn’t take a lot of sugar to add 40 or 60 calories to someone’s diet and leave everything else unchanged.