Obesity in the United States: rates, causes and where to get help

How common is obesity in the United States?

Obesity in the United States affects about four in ten adults, which puts the country at number 16 of 196 in the WHO ranking by rate. Because the population is so large, no other nation has more adults living with obesity in absolute numbers.

The WHO estimate for adults is 41.0 %. Among women it is 42.4 %, among men 39.6 %. These figures use the standard adult cut-off of a body mass index (BMI) of 30 or more; our page on what obesity is explains why BMI is only a first screening step.

America also runs its own measured survey, the National Health and Nutrition Examination Survey (NHANES). Nurses weigh and measure participants instead of asking them. Its latest round, as summarised by the public health group Trust for America's Health, also finds that around 4 in 10 adults have obesity, so the national and WHO pictures agree closely.

Big differences between states and groups

A second national source, the Behavioral Risk Factor Surveillance System, relies on telephone interviews in which people report their own height and weight. Self-reports tend to come out a little lower than measured data, but they are useful for comparing states.

In the most recent state results, West Virginia (41.4 %), Mississippi (40.4 %) and Louisiana (39.2 %) had the highest adult rates. Colorado (25.0 %), Hawaii and Massachusetts (both 27.0 %) and Washington, D.C. (25.5 %) had the lowest. Even the lowest state is well above the world average of 16.2 %.

The same report shows obesity rates of 49.9 % among Black adults and 45.6 % among Latino adults. People with a college degree or a higher household income have lower rates, and rural communities tend to have higher ones than cities. These gaps point to living conditions, not to personal failings.

Children and teenagers

The WHO puts obesity among American 5- to 19-year-olds at 21.8 %, with boys (23.3 %) a little ahead of girls (20.2 %). NHANES, which covers ages 2 to 19, reports just over 21 % as well.

Trust for America's Health notes that childhood obesity has more than tripled over the past five decades. Our page on obesity in children explains how doctors assess growth in young people, which works differently from adult BMI.

How has obesity in the United States changed since 1990?

Since 1990 the share of American adults living with obesity has gone from 18.7 % to 41.0 %, a rise of more than 22 percentage points. In other words, the rate has more than doubled within one generation.

Most of that growth happened in the first twenty years of the series, when the American rate almost doubled. Over the last fifteen years it has still crept upwards, but by a few points rather than by leaps. Among children and teens the rate almost doubled as well, from 11.4 % to 21.8 %.

There are small signs that the climb is levelling off for adults. The number of states with adult rates of 35 % or more dropped for the first time in the state survey's history, after years of steady increases. The report's authors call this progress limited and at risk, and child rates are still going up.

Why is obesity so common in the United States?

Obesity in America is driven mainly by the environment people live in: what food is cheap and close by, how towns are built, and how much time and money families have. Biology and genes decide who is most affected, as our page on the causes of obesity explains, but they cannot explain a doubling in thirty years.

A food supply built on highly processed products

Ultra-processed foods, such as packaged snacks, sweet drinks, ready meals and many breakfast cereals, make up a very large part of the American diet. A study of NHANES food diaries in the American Journal of Clinical Nutrition found that they supplied 57 % of adults' calories at the end of the period studied, up from 53.5 % at the start.

Over the same years, the share of energy coming from fresh or minimally processed food such as vegetables, fruit, eggs, plain milk and meat fell from about 33 % to 27 %. These products tend to be energy-dense, easy to overeat and heavily marketed. Our page on the food environment looks at how this works.

Money, neighbourhood and time

Trust for America's Health points to structural barriers: healthy food often costs more, some neighbourhoods have few grocery stores, and many lack safe places to walk or play. Stress, job insecurity and education shape daily choices too.

That helps explain why obesity is more common in rural areas and in households with lower incomes. When a family is short on money or time, cheap calorie-dense food is often the most practical choice, and the result is weight gain that has little to do with willpower.

Sugary drinks and snacking

Soda, sweet tea, energy drinks and fruit drinks add sugar without making people feel full. Researchers studying American city taxes note that higher prices lead to large drops in sales of these drinks. This is why several policy changes in the country, from city taxes to food assistance rules, focus on drinks first.

Health impact of obesity in the United States

The most visible health effect is diabetes: the American Diabetes Association reports that over 38 million people in the country have diabetes and nearly 98 million have prediabetes. Type 2 diabetes is closely linked to excess body fat, especially around the waist.

Obesity also raises the risk of high blood pressure, heart disease, fatty liver disease, sleep apnoea, joint pain and several cancers. Our page on the health risks of obesity covers these in plain language.

The good news is that modest change matters. Losing 5 % of body weight, for example 5 kg for someone weighing 100 kg, can already lower blood sugar and blood pressure in many people.

What is the United States doing about obesity?

The United States has no single national obesity law; action is spread over federal guidelines, food assistance rules, labelling plans, city taxes and state choices. Here are the main measures we could verify.

New federal dietary guidelines: "Eat Real Food"

The current Dietary Guidelines for Americans, published by the departments of Agriculture and Health, put whole and minimally processed food at the centre. For the first time, official guidance tells Americans to avoid highly processed food.

The guidelines suggest about three servings of vegetables and two of fruit a day, encourage whole grains, and advise cutting refined carbohydrates. The government promotes them under the name Real Food.

Limits on soda and candy in food assistance

The Supplemental Nutrition Assistance Program (SNAP) helps low-income households buy food. A growing number of states, including Idaho, Florida and Arkansas, have received federal waivers that stop SNAP benefits being used for soda, candy or similar items.

These waivers are debated, and not all of them stand. A federal court has stopped the waivers for Colorado and Iowa, so the rules differ from state to state.

A planned front-of-package label

The Food and Drug Administration (FDA) has proposed a "Nutrition Info" box on the front of most packaged foods. It would rate saturated fat, sodium and added sugars as low, medium or high, so shoppers can judge a product at a glance.

The rule is not final yet. If adopted as proposed, larger companies would get about three years to comply and smaller companies about four.

City soda taxes

There is no national soda tax, but several cities tax sweetened drinks, Philadelphia being one of the best studied.

A study in The Lancet Regional Health – Americas found limited evidence that adult BMI and obesity in Philadelphia fell slightly in the three years after its tax, compared with nearby areas. The authors say the finding still needs to be repeated elsewhere.

Coverage of obesity care

Medicare, the federal insurance for people aged 65 and over, covers intensive behavioural therapy for adults with a BMI of 30 or more. It includes a diet assessment and regular counselling sessions with a primary care clinician, aimed at healthier eating and more activity.

Coverage under private plans and Medicaid differs by insurer and by state, so it pays to ask your plan directly what is included.

Where to get help for obesity in the United States

For most people in the United States, the first step is an appointment with a primary care clinician: a family doctor, internist, nurse practitioner or physician assistant. They can check your weight, waist, blood pressure and blood sugar and talk through options.

Before the visit, our doctor visit checklist helps you prepare questions. If you are on Medicare and your BMI is 30 or more, you can ask about the covered behavioural therapy sessions.

• Obesity Medicine Association (obesitymedicine.org): a professional body with a searchable directory of clinicians trained in obesity medicine, by city, state or zip code.
• Registered dietitians: ask your clinician for a referral and check with your plan whether it pays for the visits.
• American Diabetes Association (diabetes.org): information and support if you live with prediabetes or diabetes alongside obesity.

You can also start with free support from us today, with no insurance or referral needed. It does not replace your clinician, but it can sit beside their care.

How the United States compares with the world

The United States has an adult obesity rate about two and a half times the world average: 41.0 % against 16.2 %. In 1990 the gap was already large, with 18.7 % against 6.7 % worldwide.

Within the Americas, the United States sits near the top. Chile (40.5 %) is close, Mexico (37.4 %) and Argentina (37.2 %) follow, while Canada is clearly lower at 26.0 %. Compared with other large high-income countries such as the United Kingdom (27.4 %) and Australia (30.6 %), the American rate is higher by more than ten points.

For children the contrast is just as strong: 21.8 % of American 5- to 19-year-olds live with obesity, against a global average of 8.2 %. You can compare every country on our obesity by country overview.

How Obesity Foundation can help you lose weight

Obesity Foundation helps people across the United States lose weight and feel better with good food, suitable exercise and walking. Everything below is free. Talk to your doctor first before you change how you eat or move, especially if you take medicines for diabetes or blood pressure.

• A free eating plan built on real, filling food rather than packaged products: see our eating plan.
• A walking plan that starts with a few minutes a day, even if you have not exercised in years: our walking programme.
• Gentle cardio at home that is kind to knees and hips: low-impact cardio.
• A free video meeting (in English) with our team to talk about your situation: book a meeting.
• Our club for encouragement from people on the same path: join the club.
• Free calculators for BMI, waist and calories: our tools.

You do not have to change everything at once. A daily walk, one less sugary drink and one more home-cooked meal a week are a real start, and we are here to help you build from there.