clearly calorie density alone is not it. and i don't think it's even as simple as 'palatability'. even if you mix cacao, butter, sugar, vanillin, and citric acid into candy, you can't get people to live off the candy
and brown sugar mixed with dried lemon juice and oil has been cheap for... significantly longer than the 50-year-old obesity pandemic
so, what changed? why is food now so addictive?
But HN linked an article a few years back about some research indicating that in the 1980s people ate as many or more callories, and got on average less physical activity, but were significantly less overweight. They reaction was that it was wrong, because thermodynamics, but the thermodynamic argument is a vast oversimplification. We can and do excrete plenty of energy such that other organisms post process our waste. Fat in particular can go unused with little notice. We can burn or conserve energy in ways that are hard to measure by just observing behavior. Given that complexity, it wouldn't surprise me that chronic inflammation could be a culprit. It could be the removal of a burden too, such that we are more efficient at processing calories. The food equivalent of meth amphetamine being available everywhere and cheaply doesn't help either, but enough people are studying it that I don't think it will be one simple thing.
10.1016/j.orcp.2015.08.007
But then there's the rise of the car, and of screen-based jobs/lifestyles, and other little conveniences that remove any last little bits of physical effort from life, from takeaway delivery to dishwashers to power tools.
Exercise used to be an unavoidable part of life.
That sounds more nefarious than I intended, so let me rephrase it. Modern fast food is the result of rapidly iterating, debugging, and optimizing recipes in a huge market for the last 70 years, leaving only the best selling, low cost, consistently reproducible recipes and discarding the rest. This process naturally selects recipes that contain lots of junk calories and bring in the most repeat customers.
Although many of the ingredients and similar foods have been around for centuries, it wasn't possible to do this kind of agile cooking on a massive scale until after WW2.
wouldn't it be more profitable if those recipes happened to have low caloric density, like coca-cola? then you could sell each customer six meals a day instead of three, and they'd be more profitable because they'd mostly be made out of water, which is cheaper than deodorized canola oil and palm oil, much less potatoes, texturized soy protein, mechanically separated chicken, and beef. you'd maybe have to include enough cellulose and xanthan gum to make it seem solid, but that wouldn't overcome the cost savings from removing the expensive calorie-bearing ingredients. it's even legal!
yet fast-food consumers have been gravitating to the macronutrient-rich menu items, not texturized carboxymethylcellulose jello, which would undoubtedly be widely available if it sold well. so they are following their homeostatic regulatory system to seek calories
their homeostasis is just broken
what broke the homeostasis?
i don't think it's an intentional thing or even a means to improve sales. if wendy's breaks your homeostatic feedback and mcdonald's doesn't, will that help them competitively? no, because their metabolically damaged customers will still eat at mcdonald's, except for the most loyal ones. if wendy's goes out of business, it'll take a generation for mcdonald's to see the result in terms of declining sales. even then, they're unlikely to be able to recognize that the demise of wendy's is the reason for their troubles
it's plausible that it's nothing more than 'ultra-palatable food makes you overeat, which disrupts your homeostasis'. but i'm skeptical of that because people seem to be able to eat very palatable food occasionally, or even often, without disrupting it
You're not going to make a large profit if you diverge too far from this social norm. Don't think like a startup, because we're talking about traditional multinational businesses here.
people's appetite is evidently for calories, and they commonly regulate their caloric intake or metabolic rate to within 0.5% in order to maintain their level of obesity. social norms are not capable of that kind of precision
consider, if you gain only 5 kg in ten years, which many obese mcdonalds eaters in the usa do, that's a caloric excess of 5 kcal per day. half a gram of fat per day. that's 0.3% of a metabolic rate of 1666 kcal per day or 0.2% of 2500 kcal/day. if they were to eat 0.3% less calories than they were burning instead of 0.3% more, they'd be losing 5 kg every ten years, not gaining it
so the homeostatic feedback mechanism is almost working. it's clearly not completely broken. its error is well under 1%. but it does evidently have a systematic error across the population. and fast-food optimization for profit by itself is an insufficient explanation for that
In my mind, the industry trend of 'reduced fat' products that tend to have increased sugar, and the substitution of HFCS for sugar both contribute towards easier over consumption of calories.
Not with that attitude you're not.
> So I think the real cause here is we've discovered novel ways for making huge amounts of calories both palatable and addictive in a way things have never been before.
I was just thinking about this earlier today.
I had a friend whom I would swear was actually, literally addicted to McDonald's burgers and fries. He wouldn't usually go seek out just any old burgers and fries, so I have a hard time saying he was addicted to them in general. I think that McDonald's (and to be clear, I am not blaming the Golden Arches here) had just some right taste that he could not help himself.
I don't like food particularly much at all, so I have never really felt like "oh that was so good I want more," but I can kind of see what you are saying here.
A better example is probably nuts. Nuts are super calorically dense, and it's easy to loads of them.
Fats also tend to be more filling, and aren't as addictive as sugar, especially refined sugar.
So I think the real cause here is we've discovered novel ways for making huge amounts of calories both palatable and addictive in a way things have never been before.
The closest I can think of is fruits, and they come with a lot of fiber, and again if you make it into juice, it tends to still not be palatable to drink gallons of it. Whereas people will literally drink a 2 liter of coke in a single sitting.