How the Modern Food Environment Makes Overeating the Default

Overeating in the modern world is less a personal failing than the predictable output of an environment engineered to sell more Calories. Here is how the food environment changed, why it works on you without your permission, and what you can actually do about it.

On December 2, 2025, the City of San Francisco sued the largest food companies in America, Coca-Cola, PepsiCo, Kraft Heinz, General Mills, Nestlé, Kellanova, Mondelez, Mars, Post, and ConAgra, under California’s unfair-competition law and a public-nuisance theory.¹ The city is not asking whether one shopper was tricked into one cookie. It is borrowing the argument that broke Big Tobacco: that these companies knowingly built an environment so hazardous to public health that the whole community, not the individual eater alone, is left paying for it.

You can argue about whether that case will win and its merits. It probably faces long odds, for reasons we will get to. What is harder to argue with is the premise underneath it, the one the fitness industry has spent decades ignoring while it lectured you about macros and discipline. The premise is that for most people, the food environment itself has become the main obstacle to eating well. That is the subject of this article: how the environment changed, why it works on you, whether you consent to it (or believe it does) or not, and what is actually within your reach.

Did the country lose its willpower in 1980?

In the late 1970s, roughly 15 percent of American adults had obesity. Today it is more than 40 percent.² If obesity were a straightforward failure of willpower or intelligence, then that dramatic increase forces an awkward question: did the American population suddenly become far less disciplined, or far less intelligent, over about four decades? Of course not. The human genome did not shift in two generations, and neither did the population’s character. Something in the surroundings did, and the timing of the obesity epidemic lines up with it almost exactly.

US adult obesity roughly tripled in about four decades. The genome did not change in two generations, and neither did the population’s willpower. The food environment did. Source: National Center for Health Statistics, 2026.

The rest of this piece is the specific answer to what changed. The short version is that eating has always been mostly automatic, run by habits that are themselves shaped by your surroundings and your state, not by willpower applied fresh each day. And what your surroundings put in front of you was rebuilt to sell more Calories, faster and cheaper, than ever before.

How much of your eating do you actually decide?

Most people assume eating works like a series of decisions: hunger shows up, you weigh the options, you pick one, all day long. That is not how it works, starting with the hunger itself. Appetite is not an event that arrives and waits for your verdict. It runs in the background like thirst, always on, surfacing into awareness more or less strongly depending on the moment, and you can no more decide to be less hungry than you can decide to be less thirsty. What you do about it is mostly automatic too. Most of what you eat is not decided in any deliberate sense at all. It runs on habit, on schedule, and on whatever the room happens to offer.

When researchers mapped where eating actually comes from, the triggers turned out to be things like the sight of food, the time on the clock, the size of the container, and the people nearby, not hunger or deliberation.³ Those habits are not free-floating choices you can swap out by deciding to. They are the integrated output of your biology, your psychology, and your surroundings, which is why nutrition lectures and “try harder” keep losing to the vending machine.

Your own training is the clearest illustration. Put a rack, a bar, and some plates in your garage and the odds you train go way up, because the environment has moved every lever in your favor. The lift is still yours to do, but now it is the path of least resistance instead of the thing you have to fight for. Now picture the commercial gym on the first Monday of January: traffic, a full parking lot, every rack taken, a juice bar selling 800-Calorie shakes on the way in. Your intention has not changed. The environment has made the good choice expensive and the bad one free. The food environment does the same thing, everywhere, all day, and it has been engineered by people who know precisely where to put the roadblocks. The lesson is not that you lack free will. It is that free will is a weak lever compared to the environment, and the industry has spent billions changing the environment in ways that overpower free will.

What made American food so easy to overeat?

American food became easy to overeat because three things changed at once: portions got bigger, more meals moved to restaurants and delivery, and ultra-processed foods took over the shelves. Each one nudges intake upward without asking your permission.

The first is portion size. Since the 1970s the standard American hamburger and soda have grown to somewhere between two and five times their original size, and many marketplace portions dwarf the government’s own serving-size standards: a typical cookie exceeds the federal standard by 700 percent, cooked pasta by 480 percent, and a steak by 224 percent.⁴ 

Many everyday portions dwarf the federal serving-size standards they’re measured against. Portion size drives intake almost mechanically, so bigger servings mean more eaten without any decision to overeat. Source: Young LR, Nestle M. American Journal of Public Health, 2002.

That matters because portion size drives intake almost mechanically. Pooling the experiments, doubling the portion in front of someone increases how much they eat by about 35 percent, and they do not decide to do it.⁵ In one study, people given a bigger bag of potato chips ate more chips, then ate the same dinner three hours later as if the extra Calories had never happened.⁶ The Cochrane review of these experiments lands in the same place: larger portions, packages, and plates reliably lead people to eat more, at least in the near term.⁷ Nobody at the table is choosing to overeat. Their intake is tracking the serving size.

The second change is where the food comes from. The share of Calories Americans eat from food prepared outside the home has roughly doubled, and on a given day more than six in ten adults report eating from a fast-food or full-service restaurant.⁸ Restaurant food tends to be more calorie-dense and less filling than what you would make at home, and each additional restaurant meal per week tracks with a measurably higher body-mass index.⁸ Delivery apps then removed the last bit of friction. Food delivery is now a roughly 30-billion-dollar industry with about two-thirds of Americans using at least one platform, which means the drive-through is now in your pocket, open around the clock.⁹

Between 1977 and 2006, average daily energy intake in the United States rose by roughly 570 Calories per person, driven mainly by more eating occasions and bigger portions.¹⁰

The third change contributes to the other two: what those Calories are made of. Ultra-processed foods now supply about 58 percent of the Calories American adults eat and about 67 percent of what children eat, and they make up something like 70 percent of the packaged products on grocery shelves.^11,12  Being ultra-processed is not by itself the problem. Plain Greek yogurt, whey protein isolate, canned beans, and tofu are all technically ultra-processed, and all of them keep you full. The trouble is a specific subset: foods engineered with added sugar, fat, and sodium tuned to a ratio that overruns the appetite and satiety signals that would otherwise tell you to stop. 

Why are ultra-processed foods so easy to overeat?

Ultra-processed foods are easy to overeat because processing strips out the things that would normally make you stop. Whole foods slow you down and fill you up through their physical structure. Ultra-processed foods are built to bypass that structure, so you can eat more, faster, before your body registers that enough has arrived.

Three changes arrived together and pushed intake up without asking permission: bigger portions, the shift to restaurant and delivery food, and ultra-processed foods taking over the shelves. Source.  Duffey KJ, Popkin BM. PLoS Medicine, 2011.

A whole food, a steak, a head of broccoli, an apple, comes with built-in brakes. It has intact fiber and structure that force you to chew and digest slowly, it carries water and takes up room in the gut, and it triggers the stretch and hormone signals that tell the brain you have had enough. Nutrition scientists call this the food matrix: the idea that a whole food is more than the sum of the nutrients on its label, because its components act together. The fiber, water, structure, and compounds like polyphenols and flavonoids work in concert, and that arrangement governs both how full the food makes you and how your body handles it.¹³ The concert is the point. Pull one piece out and dose it on its own and most of the effect disappears, which is why supplemental fiber does little beyond lowering cholesterol while the same fiber inside an apple travels with everything else that makes an apple filling. Whole foods fight back a little when you eat them.

Ultra-processed foods break that concert. Refine the carbohydrate, remove the fiber, soften the texture so it nearly dissolves, and then tune the salt, sugar, and fat toward the ratio the market researcher Howard Moskowitz called the bliss point, the level of each that the tongue reads as exactly right.¹⁴ Adding an isolated nutrient back to a stripped product, a spray of fiber or a dusting of vitamins, does not rebuild what was lost, because the effect was never in any single part. What is left is a product engineered for maximum reward and minimum feedback. In a whole-food diet your body has working brakes. In an ultra-processed one, the stop lights have been turned green and the brake lines cut.

The experiment that pins this down produced a result that runs against the obvious read. You might assume the extra eating comes from the sugar, or the fat, or the calorie density, the usual suspects. Kevin Hall’s team at the NIH built a study to rule those out. They admitted 20 adults to a research ward and fed them, in random order, two weeks of mostly ultra-processed food and two weeks of mostly unprocessed food. The two menus were matched for the Calories offered, along with protein, carbohydrate, fat, sugar, salt, and fiber, and subjects could eat as much or as little as they wanted.¹⁵ The key is that word, offered. As in the food environment more broadly, what was held equal was availability, not intake. Because everything on paper was matched, whatever difference showed up in how much people actually ate comes down to the processing itself. On the ultra-processed weeks people ate about 500 Calories a day more and gained weight; on the unprocessed weeks the same people ate less and lost it.¹⁵ Same person, same willpower, same nutrients on paper. What moved intake by 500 Calories was the processing, specifically how fast the food could be eaten and how weakly it signaled fullness.

In a controlled inpatient trial, the same people ate about 500 Calories more per day on an ultra-processed diet than on an unprocessed one, even though the two menus offered identical Calories and macros. The variable that moved intake was the processing itself. Source: Hall KD, et al. Cell Metabolism, 2019.

How tobacco companies shaped processed food

The modern food environment was built on purpose, and for a stretch of it, the builders were the tobacco industry. In the 1980s the two largest tobacco companies on earth moved into American food. R.J. Reynolds acquired Nabisco in 1985, and Philip Morris bought General Foods in 1985 and Kraft in 1988.¹⁴ They brought more than money. They brought the scientists who had spent careers optimizing the rate of nicotine absorption and pointed them at mouthfeel and the bliss point, and they brought the marketing machinery that had made a cartoon camel sell cigarettes and aimed it at snacks for children.¹⁴

On an April morning in 1999, eleven of the most powerful food executives in the country met at Pillsbury’s headquarters in Minneapolis to talk about obesity. A Kraft vice president named Michael Mudd warned them, with slides, that they were on track to be treated like the tobacco industry and needed to pull back on sugar and marketing. The chief executive of General Mills, Stephen Sanger, gave the room its answer: “Don’t talk to me about nutrition. Talk to me about taste.”¹⁴ 

Through decades of lobbying, corn, soy, and wheat became the most subsidized crops in the country, which is a large part of why a shelf-stable snack cake has stayed cheap and stable in price for forty years while fresh produce has not. When a box of cookies is cheaper than a head of broccoli, the “choice” facing a family on a budget has been shaped by farm policy before they reach the store. The store itself is not neutral either. Checkout lanes and end-caps are prime real estate that manufacturers pay slotting fees to occupy, and one audit of California stores found that about 70 percent of the food and drink stocked at checkout was unhealthy, rising to nearly 89 percent among snack-sized packages.¹⁶ Those are the shelves that catch you when you are tired, distracted, and standing in line with a kid.

Are ultra-processed foods addictive?

For a meaningful share of people, ultra-processed foods seem addictive, though the science is genuinely contested. Using the Yale Food Addiction Scale, which applies the same clinical criteria used for alcohol and tobacco, roughly 14 percent of adults and 12 percent of children meet the bar for ultra-processed food addiction, a rate comparable to alcohol use disorder and somewhat below tobacco.¹⁷ The San Francisco suit leans on exactly this, arguing these products are not merely hard to resist but addictive.

Where researchers split is on what that number means. One camp holds that these foods behave like a drug: a refined, rapidly absorbed mixture engineered for effect, with the food playing the role nicotine plays in a cigarette. The other camp points out that there is no single “nicotine” molecule here. People do not binge on pure sugar or plain butter; they overconsume specific engineered combinations in specific contexts, and this camp argues that much of what looks like addiction is the body’s normal, homeostatic response to restriction and weight loss, cranking up the drive to eat. Through that lens, the problem is less a chemical hook than an environment that reliably triggers uncontrolled eating. My take sits closer to the second view. The label matters less than the mechanism, and the mechanism is an environment tuned to override the signals that would otherwise make you stop.

For the lawsuit, the distinction may not matter as much as it seems. A public-nuisance claim does not require that everyone be addicted. If a bridge were built so poorly that 14 percent of the cars crossing it went off the edge, nobody would call it safe because most drivers made it. The point of the addiction data is narrower than the headlines: it is evidence that the product can override agency in a meaningful share of people, which is enough to undercut the “you chose to eat it” defense the industry has leaned on for two decades.

Are ultra-processed foods as bad as people claim?

Ultra-processed foods do real harm at a population level, but the danger is narrower and more specific than the headlines suggest. The evidence is softer than it looks, the additives everyone worries about are mostly a distraction, and the harm runs through one mechanism above all: they get you to eat more. Being precise about this is what separates a useful position from a scare campaign.

Let’s start with the health data. A BMJ umbrella review pooling nearly ten million people found that higher ultra-processed food intake is associated with roughly 50 percent higher cardiovascular mortality, about 55 percent higher odds of obesity, a 12 percent higher risk of type 2 diabetes for every 10 percent increase in intake, and about 22 percent higher risk of depression.¹⁸ Those are large numbers, but they are also observational associations that the review itself grades as low to very-low certainty, with the caveat that unmeasured factors could be driving part of the effect. The most likely path from these foods to disease is not some Calorie-independent toxin. It is that they make you eat more, and the excess energy does the damage over time. Self-reported diet studies consistently undercount calories, especially from exactly these foods, so hunting for harm “independent of calories” often misses that the overeating is the harm.

Next is the temptation to chase villains. Most of this conversation runs on the NOVA classification, a system that sorts food by how much industrial processing it has undergone rather than by its nutrients. NOVA is a blunt instrument. It files a whey protein isolate and an Oreo in the same “ultra-processed” bin, which is a bit like saying a bicycle and a 747 are the same because both contain metal. The useful question is not whether a food was processed but whether it defends or defeats your fullness. A frozen bag of spinach, plain Greek yogurt, and canned beans are processed and on your side; a fiber-stripped, bliss-pointed snack is processed and against you.

Whether a food is “ultra-processed” tells you less than whether it defends or defeats your fullness. This screen sorts tools from traps in a few seconds at the shelf.

The heavily litigated additives are mostly a sideshow next to that distinction. Red Dye 40 has a real but modest evidence base, largely around behavioral effects in a subset of sensitive children, and the omega-6 fats in seed oils, which the largest pooled analysis to date links to lower cardiovascular risk rather than higher, are closer to protective than harmful.¹⁹ Spending your limited attention there while ignoring a 500-Calorie satiety gap is repainting the lifeboats on a sinking ship. Worse, telling a parent whose budget only reaches shelf-stable calories that their food is poison, with no affordable alternative offered, turns basic health into a luxury good.

We should say that the lawsuit deserves the same skepticism. The public-nuisance theory is far from proven ground for consumer products. The most celebrated version of it, the 2019 Oklahoma verdict against Johnson & Johnson over the opioid epidemic, was overturned by that state’s supreme court in 2021, which held that public-nuisance law does not stretch to cover the manufacture and marketing of a product.²² The last serious wave of obesity suits against fast food failed on their core claims as well.²⁰ The pattern has held into the current wave. In June 2026, a federal court in Pennsylvania permanently dismissed a separate suit, brought by a Philadelphia teenager who blamed 179 ultra-processed products for his type 2 diabetes and fatty liver, ruling that naming the products he ate did not establish that any specific one caused his disease, and that the law does not let a plaintiff hold an entire industry liable at once.²¹ San Francisco’s action is a different animal, a state enforcement action over public costs rather than one person’s illness, which is why a federal judge sent it back to state court in April 2026 after the companies tried to move it. It is a slow, uncertain fight, but what you do regarding your health is happening now.

How do you eat well in this food environment?

The move is to redesign the small slice of the environment you control so the healthy choice becomes the path of least resistance. Long-term, you cannot out-discipline a system built to defeat discipline, and you do not have to wait for a court to redesign the grocery store. A handful of changes do most of the heavy lifting here.

Decide once, at the store, instead of every night in the kitchen. If the hyper-palatable food and drinks are in the house, you have to spend willpower resisting them every single evening. If you skip them on the weekly trip to the store, you spend that willpower once.

Stock a satiety-first kitchen. Fill it with foods that keep you full per Calorie: beans, tuna, frozen vegetables and fruit, ultra-filtered milk, plain Greek yogurt, fruit, and lean proteins. A simple screen for a packaged food is whether it gives you at least 30 percent of its calories from protein or at least a gram of fiber for every 10 grams of carbohydrate; clear that bar and it is a tool, not a trap. Aiming protein toward roughly 1.6 grams per kilogram of body weight covers muscle, and protein at that level keeps you full on top of it.

Cook at home more often than you do now. Home meals tend to be lower in Calories, smaller in portion, and more filling than restaurant or delivery food, and when you cook you are the one setting the portion and the recipe. Learning to prepare and store food pays off more than almost anything else you can do here.

Use friction on purpose. If hyper-palatable snacks are in the house for kids or guests, put them out of sight in opaque containers or high cabinets, and keep the high-satiety options at eye level. Your desk and office are usually stocked with donuts and vending machines, so bring your own protein-forward food and stop relying on the breakroom.

Eat without a screen. When you eat while scrolling or watching television, you mute the brain’s ability to register the stop signals your gut is sending, the same blindness the engineered foods exploit. Eating undistracted, at reasonably consistent times, lets those signals land.

If the signals still are not working, that is a medical problem, and it has medical tools. GLP-1 medications, cognitive behavioral therapy, and metabolic bariatric surgery all work on the same appetite machinery the food environment exploits. Using them is not cheating; it is treating the problem at the level where it actually operates, which is in the brain.

Take Home

San Francisco is trying to fix the food environment for a whole city at once. It may lose in court, and the case may drag on for years. None of that changes the thing worth taking from it: the food environment it describes is real, it was built on purpose, and it has been beating your intentions on purpose too. If you have spent years trying and failing to eat the way you mean to, you were not weak. You were outmatched by a system doing exactly what it was designed to do.

You cannot personally out-argue farm subsidies, slotting fees, and a hundred years of food science. What you can do is decide what is kept in the house and office, what sits at eye level, and where your next meal comes from. That is a smaller environment than the one San Francisco is fighting over, but it is the one you actually eat in every day, and it is enough to change the result. Until the bigger fight is settled, build the smaller one deliberately. If you want a hand doing it, our coaching team does this with people every day, pairing nutrition, training, and medical care in one place.

References

1. Office of the City Attorney of San Francisco. San Francisco City Attorney Chiu sues largest manufacturers of ultra-processed foods. Press release; December 2, 2025. https://sfcityattorney.org/san-francisco-city-attorney-chiu-sues-largest-manufacturers-of-ultra-processed-foods/

2. National Center for Health Statistics. Prevalence of overweight, obesity, and severe obesity among adults age 20 and older: United States, 1960-1962 through August 2021-August 2023. NCHS Health E-Stats. Hyattsville, MD: National Center for Health Statistics; 2026. https://www.cdc.gov/nchs/data/hestat/hestat111.htm

3. Cohen DA, Farley TA. Eating as an automatic behavior. Prev Chronic Dis. 2008;5(1):A23.

4. Young LR, Nestle M. The contribution of expanding portion sizes to the US obesity epidemic. Am J Public Health. 2002;92(2):246-249. https://doi.org/10.2105/ajph.92.2.246

5. Zlatevska N, Dubelaar C, Holden SS. Sizing up the effect of portion size on consumption: a meta-analytic review. J Mark. 2014;78(3):140-154. https://doi.org/10.1509/jm.12.0303

6. Rolls BJ, Roe LS, Kral TVE, Meengs JS, Wall DE. Increasing the portion size of a packaged snack increases energy intake in men and women. Appetite. 2004;42(1):63-69. https://doi.org/10.1016/S0195-6663(03)00117-X

7. Hollands GJ, Shemilt I, Marteau TM, Jebb SA, Lewis HB, Wei Y, et al. Portion, package or tableware size for changing selection and consumption of food, alcohol and tobacco. Cochrane Database Syst Rev. 2015;(9):CD011045. https://doi.org/10.1002/14651858.CD011045.pub2

8. Bhutani S, Schoeller DA, Walsh MC, McWilliams C. Frequency of eating out at both fast-food and sit-down restaurants was associated with high body mass index in non-large metropolitan communities in Midwest. Am J Health Promot. 2018;32(1):75-83. https://doi.org/10.1177/0890117116660772

9. Stephens J, Miller H, Militello L. Food delivery apps and the negative health impacts for Americans. Front Nutr. 2020;7:14. https://doi.org/10.3389/fnut.2020.00014

10. Duffey KJ, Popkin BM. Energy density, portion size, and eating occasions: contributions to increased energy intake in the United States, 1977-2006. PLoS Med. 2011;8(6):e1001050. https://doi.org/10.1371/journal.pmed.1001050

11. Martínez Steele E, Baraldi LG, Louzada ML, Moubarac JC, Mozaffarian D, Monteiro CA. Ultra-processed foods and added sugars in the US diet: evidence from a nationally representative cross-sectional study. BMJ Open. 2016;6(3):e009892. https://doi.org/10.1136/bmjopen-2015-009892

12. Wang L, Martínez Steele E, Du M, Pomeranz JL, O’Connor LE, Herrick KA, et al. Trends in consumption of ultraprocessed foods among US youths aged 2-19 years, 1999-2018. JAMA. 2021;326(6):519-530. https://doi.org/10.1001/jama.2021.10238

13. Aguilera JM. The food matrix: implications in processing, nutrition and health. Crit Rev Food Sci Nutr. 2019;59(22):3612-3629. https://doi.org/10.1080/10408398.2018.1502743

14. Moss M. The extraordinary science of addictive junk food. The New York Times Magazine. February 20, 2013. https://www.nytimes.com/2013/02/24/magazine/the-extraordinary-science-of-junk-food.html

15. Hall KD, Ayuketah A, Brychta R, Cai H, Cassimatis T, Chen KY, et al. Ultra-processed diets cause excess calorie intake and weight gain: an inpatient randomized controlled trial of ad libitum food intake. Cell Metab. 2019;30(1):67-77.e3. https://doi.org/10.1016/j.cmet.2019.05.008

16. Falbe J, Marinello S, Wolf ECM, Solar SE, Grummon AH, Cash SB, et al. Food and beverage environments at store checkouts in California: mostly unhealthy products. Curr Dev Nutr. 2023;7(6):100075. https://doi.org/10.1016/j.cdnut.2023.100075

17. Gearhardt AN, Bueno NB, DiFeliceantonio AG, Roberto CA, Jiménez-Murcia S, Fernández-Aranda F. Social, clinical, and policy implications of ultra-processed food addiction. BMJ. 2023;383:e075354. https://doi.org/10.1136/bmj-2023-075354

18. Lane MM, Gamage E, Du S, Ashtree DN, McGuinness AJ, Gauci S, et al. Ultra-processed food exposure and adverse health outcomes: umbrella review of epidemiological meta-analyses. BMJ. 2024;384:e077310. https://doi.org/10.1136/bmj-2023-077310

19. Marklund M, Wu JHY, Imamura F, Del Gobbo LC, Fretts A, de Goede J, et al. Biomarkers of dietary omega-6 fatty acids and incident cardiovascular disease and mortality. Circulation. 2019;139(21):2422-2436. https://doi.org/10.1161/CIRCULATIONAHA.118.038908

20. Pelman v. McDonald’s Corp., 396 F.3d 508 (2d Cir. 2005). https://caselaw.findlaw.com/us-2nd-circuit/1181336.html

21. An ultra-processed complaint fails: federal court dismisses ultra-processed food injury suit (Martinez v. Kraft Heinz Foods Co. et al.), US District Court, Eastern District of Pennsylvania; July 2026. Holland & Knight; 2026. https://www.hklaw.com/en/insights/publications/2026/07/an-ultra-processed-complaint-fails

22. State ex rel. Hunter v. Johnson & Johnson, 2021 OK 54, 499 P.3d 719 (Okla. 2021). https://law.justia.com/cases/oklahoma/supreme-court/2021/118474.html