What Is Obesity? BMI Ranges, Causes, Treatment, Prevention, and Statistics

If your doctor has recommended lowering your BMI to move out of the obesity category, here are some potential treatment options to explore along with help from your healthcare team.

Diet and Lifestyle Changes

First, make daily changes to how you eat and live. “We always encourage patients to try to diet and exercise first because that is the most safe method for weight loss,” says Dr. Ali. Be sure to speak with your doctor and potentially a registered dietitian-nutritionist before embarking on any diet or exercise plan, to ensure you are making changes that are safe and appropriate for you.

Diet

There are a variety of diets that may help support your efforts to lose and maintain weight loss, but 2020–2025 Dietary Guidelines for Americans say that whichever you choose should do the following, whether you are trying to lose or maintain weight as an adult:

• Emphasize nutrient-dense foods and beverages, which include fruits, vegetables, whole grains, fat-free or low-fat milk and milk products, fortified soy beverages, lean meats, poultry, fish, beans, eggs, vegetable oils, nuts, and seeds (with a greater emphasis on beans and peas, soy products, nuts, and seeds if you are vegetarian).
• Stay within your daily calorie needs.
• Limit intake of added sugars, saturated fats, sodium, and alcohol, specifically:

• Added sugars: less than 10 percent of calories per day
• Saturated fat: less than 10 percent of calories per day
• Sodium: less than 2,300 milligrams per day

• Alcoholic beverages: Drink in moderation by limiting intake to two drinks or less in a day for men and one drink or less in a day for women, when alcohol is consumed. Drinking less is better for health than drinking more.

Calorie needs vary by age, sex, height, weight, activity level, and whether you are trying to lose, gain, or maintain weight. For adult women the recommended range is 1,600 to 2,400 calories per day, and for adult men the range is 2,000 to 3,000 calories per day. For children ages 2 to 8 the range is from 1,000 to 2,000, and for older children and adolescents the range is 1,400 to 3,200. The dietary guidelines include a chart where you can find the calorie target that suits you best.Your primary care doctor and a registered dietitian-nutritionist, among other specialists, can help provide more individualized advice, especially in cases where you are looking to manage other underlying health conditions.

Exercise

According to federal physical activity guidelines for Americans, aim for the following level of physical activity, even if you are not trying to lose weight:

For adults:

• Do at least 150 minutes to 300 minutes a week of moderate-intensity exercise (like walking briskly, line dancing, yoga, playing doubles tennis, or raking leaves).
• Alternatively, do 75 minutes to 150 minutes a week of vigorous-intensity aerobic physical activity, such as jogging, running, cycling more than 10 miles an hour, or high-intensity interval training (HIIT).
• Older adults with chronic conditions should do as much activity as their health allows.

For youths:

• Preschool-age children should remain active throughout the day and be encouraged to play or otherwise move their bodies.
• Children 6 to 17 years old should do an hour or more of moderate to vigorous physical activity daily.

“In the National Weight Control Registry over 90 percent of those who maintained long-term weight loss engaged in at least 60 minutes per day of physical activity,” Dr. Kane notes.

Meanwhile, if you are at the beginning of your weight loss journey and have a lot of weight to lose, be patient with yourself, he advises. Patients with obesity beginning an exercise program must think of the long term. In the end they will want to be engaged in regular physical activity, but it takes time to build up strength, endurance, and flexibility. Be persistent, but safe.”

Medication Options

If diet and exercise alone aren’t enough to get you to a healthy weight, and your BMI is 30 or more (or your BMI is 27 to 29.9 and you have a complication such as type 2 diabetes or high blood pressure), your doctor may prescribe medication to add to your regimen, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).

Among the more common medications listed by the NIDDK that are approved by the U.S. Food and Drug Administration (FDA) for long-term use are:

• orlistat (Xenical), which is available at a lower dose without a prescription under the name Alli
• phentermine-topiramate (Qsymia)
• naltrexone-bupropion (Contrave)
• liraglutide (Saxenda), an injectable that is also FDA approved at a lower dose to treat type 2 diabetes under the name Victoza
• semaglutide (Wegovy), an injectable that is also FDA approved to treat type 2 diabetes
• setmelanotide (IMCIVREE), an injectable that is also FDA approved for children with Bardet-Biedl syndrome who are 6 or older
• tirzepatide (Zepbound), and injectable that is also FDA approved to treat type 2 diabetes under the brand name Mounjaro.

Perez-Colon notes that these medications are approved for children:

• orlistat (Xenical)
• phentermine-topiramate (Qsymia)
• phentermine
• liraglutide (Saxenda), an injectable that is also FDA approved at a lower dose to treat type 2 diabetes under the name Victoza

She says that the type 2 diabetes medication metformin (Glucophage) has sometimes been prescribed for weight loss in adolescents, along with other interventions, but it is not FDA approved for that use because studies are mixed. A review that followed overweight or obese people who were given metformin found that adults experienced a small amount of weight loss over time.

“[Some] obesity medications at higher doses can cause more rapid weight loss, but one typically sees weight regain without continuing them indefinitely,” Kane cautions.

Mounjaro (tirzepatide) is an FDA-approved medication used to improve blood sugar control in adults with type 2 diabetes. It was approved in November 2023 to treat obesity under the name Zepbound. Tirzapatide helped people with obesity (or a BMI above 27 with an obesity complication) lose 18.4 percent of their body weight (21.5 pounds) on average compared with a 2.5 percent weight loss (3.5 pounds) with placebo over a year and a half, when used along with dietary changes and exercise, according to a study in the journal Nature Medicine.

Weight loss medications can be pricey, and they’re not always covered by health insurance, which makes them inaccessible to many people.

Mental Health Options for Behavioral Change

Research suggests there’s a two-way relationship between obesity and mental health. A previous analysis of studies determined that obesity increases the risk of depression, especially among Americans; and also that depression is a risk factor for developing obesity.

The CDC reports that 43 percent of adults with depression were obese, compared with 33 percent of adults without depression, as of 2010. This greater risk of obesity was especially strong in white women. Rates of obesity by depression status did not differ among men across groups, nor did they differ in Black and Mexican American women and men.

“The good news is that weight loss efforts, with the help of a mental health professional, can help one cope and develop strategies to reverse or at least diminish the negative feelings,” says Dominick Gadaleta, MD, a bariatric surgeon in Bay Shore, New York.

Also notable is people who have a history of childhood trauma may be at an increased risk for health conditions such as obesity, research suggests.

If you are seeking professional counseling related to your weight or your perception of it, speak with your doctor for a referral, or do a key phrase search for “obesity” and “weight-loss” in the American Psychological Association’s Psychologist Locator to find a therapist in your area.

Surgery Options

For people with severe obesity who have not been able to lose the weight they desire to through diet, exercise, and medication, weight loss surgery may be an option. Ali says that patients who come to him for surgery are typically 100 pounds overweight.

The American Society for Metabolic and Bariatric Surgery (ASMBS) says other qualifications for bariatric surgery include having a BMI of 40 or greater (even if you are less than 100 pounds overweight); or having a BMI of 35 to 39.39 along with obesity-related complications such as type 2 diabetes, high blood pressure, heart disease, osteoarthritis, nonalcoholic fatty liver disease, sleep apnea, or other breathing problems. Candidates usually undergo thorough psychological counseling and a medically supervised diet before surgery, according to the organization, per the ASMBS.

Weight loss surgery leaves a patient with a stomach that can hold far less food than before, and most options also restrict the body’s ability to absorb calories and nutrients. The procedures are typically minimally invasive laparoscopic surgeries, according to the ASMBS.

Ali says the most common surgery types are:

Laparoscopic Sleeve Gastrectomy (Sleeve)

About 80 percent of the stomach is surgically removed from the body, leaving a banana-shaped pouch, as the ASMBS describes it. The amount of food that can be consumed is drastically reduced by the procedure, and changes happen in gut hormones that suppress hunger, make you feel full when you eat, and reduce high blood sugar. People lose around half of their excess weight on average within the three- to five-year time frame, and maintain that level of loss in the long term, according to the association.

Other less common bariatric surgeries include biliopancreatic diversion with duodenal switch (BPD-DS) gastric bypass and laparoscopic adjustable gastric band (lap band), says Ali. The ASMBS describes how they work.

Roux-en-Y Gastric Bypass (Gastric Bypass)

As the ASMBS explains, in this procedure, the stomach is divided into two sections by a surgeon and only one small part of it holds the food you eat. The lower part of the small intestine is attached directly to that small stomach pouch, so that food can bypass most of the stomach and the upper part of the small intestine. As a result, the body absorbs fewer calories. Then the bypassed section is connected further down to the lower part of the small intestine — still attached to the main part of your stomach — so digestive juices can move from your stomach and the first part of your small intestine into the lower part of your small intestine.

Rerouting the food stream alters gut hormones that suppress hunger, make you feel full when you eat, and reduce high blood glucose (sugar). People lose on average 60 to 80 percent of their excess weight, and maintain a loss of at least 50 percent in the long term, according to ASMBS.

Intragastric Balloon Therapy (IGB)

For people who have a BMI of 30 to 39.9, with or without other chronic health conditions, this less-invasive procedure is an option. According to the FDA, a surgeon places one or more inflatable balloons into the stomach endoscopically or through a capsule that is attached to a catheter and swallowed. The balloons are then filled with gas or saline and then sealed to take up space in the stomach and delay the exit of food from the stomach into the small intestine. The balloons are removed at a later date. According to Mayo Clinic, typical weight loss is about 7 to 15 percent of your body weight during the six months after balloon placement, and total excess weight loss is in the 30 to 47 percent range.

After the surgery, people must stick to a high-protein, very low carbohydrate diet with small portions per meal, says Ali. The regimen helps to prevent dumping syndrome, in which overly rapid movement of food into the small intestine can cause abdominal cramping, nausea, vomiting, and low blood sugar, the Cleveland Clinic explains.

“As long as you are getting the amount of calories your body needs each day and not eating in excess of that, then you can maintain the weight loss,” says Ali.

Learn More About Weight Loss Surgery

Complementary and Integrative Approaches

Several complementary and integrative approaches can be used along with conventional medical interventions to help with obesity treatment.

“There is a role for a traditional [conventional] physician, and there’s also a role for an integrative health practitioner,” said Laura Purdy, MD, a board-certified family medicine physician who operates a virtual clinic. “It is so important to have good communication between all of the people on your healthcare team, so that you can have the very best transparent, patient-centered care possible,” she added.

These approaches include, per the National Center for Complementary and Integrative Health:

• Dietary supplements (though research on their efficacy is limited)
• Mind-body approaches such as yoga and meditation

While many of these practices are considered low-risk, Dr. Purdy still recommends talking to a physician before choosing an integrative approach to add to your treatment. With supplements in particular, work with your healthcare team to ensure what you’re interested in taking doesn’t interfere or negatively react with any medications you may be taking.

Learn More About Obesity Treatment