Obesity has tripled: how sugar and processed food took over the grocery store

U.S. obesity has tripled since the 1960s

Share of people with obesity:

• 1890s: about 3% of middle-aged American men, based on Union Army veteran records
• Early 1960s: about 13% of U.S. adults
• Today: about 40% of U.S. adults

Worldwide, adult obesity has more than doubled since 1990. In 2022, about 1 in 8 people had obesity.

Genes can’t change that fast, but food can. Inactivity probably isn’t the main cause of the rise: Hadza hunter-gatherers in Tanzania walk miles a day but burn about as many calories per day as Western adults of the same size. Exercise matters for health, but food drives weight more.

Sugar went from luxury to staple

Once colonial plantations and industrial refining made sugar cheap, English intake rose from about 4 pounds per person per year in 1700 to about 90 by 1900, according to historian Sidney Mintz. Today, the average American eats about 17 teaspoons of added sugar a day, well above the recommended limit.

Food became a factory product

Steel roller mills began producing fine white flour in the 1870s. Cheap high-fructose corn syrup spread through soda and packaged foods in the 1970s. Ultra-processed foods are industrial products made mostly from refined ingredients and additives, like soda, chips, sweetened cereals, and most fast food. They make up about 57% of the calories U.S. adults eat, and about 67% for kids and teens.

Sugar addiction: shown in rats, unproven in humans

In a 2007 French study, about 94% of rats chose sweetened water over an IV dose of cocaine, including rats already using cocaine.

In humans, sugar alone hasn’t been proven addictive the way drugs are. Stronger evidence points to ultra-processed foods, which combine sugar, fat, and refined starch in ways whole foods don’t. A 2023 review in The BMJ estimated that about 14% of adults and 12% of children meet the criteria for ultra-processed food addiction. The adult rate is similar to alcohol addiction rates.

Most packaged food contains sugar

Of more than 85,000 packaged foods and drinks bought by U.S. households, about 74% contained sweeteners, and 68% contained caloric ones like sugar, corn syrup, or fruit juice concentrate. That includes foods that don’t taste sweet, like bread, pasta sauce, salad dressing, and deli meat.

Labels list sugar under more than 60 names, such as dextrose, maltose, and rice syrup. Most added sugar sits in the store’s middle aisles. Whole foods line the edges.

The sugar industry shaped the science

Documents uncovered in 2016 by UC San Francisco researchers show a sugar industry group paid Harvard scientists in the 1960s to write a review blaming fat, not sugar, for heart disease. The review ran in a top medical journal in 1967 without disclosing the funding. For decades afterward, low-fat products filled the shelves, often with extra sugar to replace lost flavor.

Ultra-processed food makes you eat more

In a 2019 National Institutes of Health study, adults in a research unit spent two weeks each on ultra-processed and unprocessed diets, eating as much as they wanted. Meals offered were matched for calories, sugar, fat, and fiber. On the ultra-processed diet, they ate about 500 more calories a day and gained about 2 pounds in two weeks. On the unprocessed diet, they lost weight.

Effects on your body and skin

Too much sugar and processed food drives weight gain, insulin resistance (cells responding poorly to insulin), fatty liver, type 2 diabetes, heart disease, and inflammation.

In a randomized trial, young men on a low-glycemic diet (foods that raise blood sugar slowly) had fewer acne spots than men on a typical diet. Obesity is linked to more severe psoriasis. In overweight people already treated for psoriasis, adding diet and exercise improved their skin more than treatment alone.

How to cut sugar

• Build most meals from produce, meat, fish, eggs, dairy, beans, and whole grains.
• Check “added sugars” on the nutrition label.
• Cut sweetened drinks first. Soda, sweet coffee drinks, and juice are often the biggest single source of added sugar.
• Choose whole fruit. Its fiber and water slow the sugar and fill you up.
• Eat protein at every meal to stay full and steady cravings.
• Cook simple home meals. They have far less hidden sugar than packaged ones.
• Give it three months. In one study, cutting back on sugar for three months made sweet foods taste sweeter, so less sugar satisfied people.
• Sleep enough. Short sleep increases hunger and sweet cravings.

What to track

For two weeks, log sweetened drinks, packaged snacks, and desserts, plus sleep, cravings, energy, mood, and skin. For many people, sugary days bring an afternoon energy crash and skin changes a day or two later. A short daily check-in makes those links easy to see.