Obesity is a medical condition where a person has too much body fat, and his or her weight is higher than what is considered healthy. This is determined by measuring your body mass index (BMI).

Smiling woman holding hand weightsSmiling woman holding hand weights

Causes and risk factors for obesity

Obesity is typically caused by a combination of genetic and behavioral factors. According to the Centers for Disease Control and Prevention (CDC), these causes and factors include:

  • Behavior and lifestyle. People with obesity may not choose healthy behaviors such as a healthy diet pattern and regular physical activity.
  • Community environment. Community, home, child care, school, health care and workplace settings can all influence people’s daily behaviors. For example, a person may choose not to walk or bike to the store or to work because of a lack of sidewalks or safe bike trails.
  • Genetics. Studies have identified variants in several genes that may contribute to obesity by increasing hunger and food intake. Rarely, a clear pattern of inherited obesity within a family is caused by a specific variant of a single gene (monogenic obesity). Most obesity, however, probably results from complex interactions among multiple genes and environmental factors that remain poorly understood (multifactorial obesity).
  • Diseases and drugs. Some illnesses may lead to obesity or weight gain, such as Cushing’s disease and polycystic ovary syndrome. Drugs such as steroids and some antidepressants may also cause weight gain.

Other contributing factors

Certain other factors may increase the risk for obesity as well:

  • Pregnancy. Weight gain is common during pregnancy and may contribute to obesity in women.
  • Previous attempts to lose weight or “yo-yo dieting.” This can slow your metabolism, resulting in rapid weight gain after losing weight.
  • Quitting smoking. Weight gain happens when people use food to cope with smoking withdrawal.
  • Sleep problems. Lack of sleep or too much sleep can cause changes in hormones that increase your appetite.
  • Stress. We all experience stresses in our daily lives and many of us naturally turn to “comfort foods.”

Degrees of obesity

You would be diagnosed as obese rather than overweight when your BMI is 30 or higher.

  • If your BMI is less than 18.5, you are within the underweight range.
  • If your BMI is 18.5 to 25, you are within the normal range.
  • If your BMI is 25 to 30, you are within the overweight range.
  • If your BMI is 30 or higher, you are within the obese range.

How do I figure out my body mass index (BMI)?

> Use this handy tool on the Centers for Disease Control (CDC) website

Categories of obesity

  • Class 1: BMI of 30 to 35.
  • Class 2: BMI of 35 to 40.
  • Class 3: BMI of 40 or higher. Class 3 obesity is categorized as morbid or severe obesity.

How obesity can affect your health

We take obesity very seriously because it is the leading cause of death in the U.S. and worldwide. According to the CDC, people with obesity are at increased risk for many serious diseases and health conditions like Type 2 diabetes.

Other possible health problems include:

  • Body pain and difficulty with physical functioning.
  • Cancer, including cancer of the uterus, cervix, endometrium, ovary, breast, colon, rectum, esophagus, liver, gallbladder, pancreas, kidney and prostate.
  • Coronary heart disease.
  • Gallbladder disease.
  • High blood pressure (hypertension).
  • High LDL cholesterol, low HDL cholesterol or high levels of triglycerides (dyslipidemia).
  • Low quality of life.
  • Mental illness such as clinical depression, anxiety and other mental disorders.
  • Osteoarthritis.
  • Sleep apnea and breathing problems.
  • Stroke.

Losing just five to 10 percent of your weight can delay or prevent some of these diseases, even if you are very obese.

Treating and preventing obesity

The benefits of healthy weight loss can positively affect everything in your life.

Your primary care provider will work with you on the best treatment plan for your body type and lifestyle, and set goals to help you lose weight and maintain a healthy BMI. It will take long-term commitment and consistency on your part – and we are always available to help. Your plan will start with changes to your diet and exercise routine:

  • Eating healthy. You will get expert and proven dietary advice that will focus on eating low-calorie, nutrient-dense foods, such as fruits, vegetables and whole grains. You will also learn to avoid saturated fat, alcohol and your unhealthy trigger foods, such as sweets. A well-balanced diet every day is key.
  • Exercising regularly. You may want to consider working with one of our physical therapists to develop the right plan to keep you active most every day.
  • Monitoring your weight. We know that weighing yourself at least once a week leads to a sense of achievement and more success in the long run.

Your provider may also include medications to help, such as orlistat (Alli, Xenical), phentermine/topiramate (Qsymia), bupropion/naltrexone (Contrave), or liraglutide (Saxenda, Victoza).

Healthy weight loss

The benefits of healthy weight loss through diet and exercise can positively affect everything in your life. You will feel better and improve your health in many ways, such as lowering your blood pressure and decreasing your risk for heart attack and stroke.

Healthy weight loss means losing weight gradually and steadily, 1 to 2 pounds per week until you reach your goal. Plus, it is not a temporary diet—it is lifestyle changes you make toward healthy eating and regular physical activity. You will lose the weight you want and be more successful at keeping it off.

Your primary care provider will work with you to develop the right weight-loss plan for your unique goals.

Weight loss surgery

Your provider may recommend weight-loss surgery, also called bariatric surgery, if other treatments aren’t working well and you have a BMI of 40 or higher.

Weight management in primary care

Get individualized weight management support with PATHWEIGH.

UCHealth integrates weight management into primary care, providing a collaborative and supportive environment for patients. This innovative approach addresses the underlying causes of obesity-related health problems.

PATHWEIGH is NOT a weight loss program. It is a care process that focuses on reducing excess body weight and weight-related medical complications. Patients receive highly individualized, flexible and evolving care based on their needs, access and preference. This care is provided in the comfort and familiarity of primary care where a long-term relationship is key to success.

By prioritizing weight loss discussions in primary care, UCHealth aims to help patients lose three times more weight compared to other methods and tackle over 200 associated health problems.

PATHWEIGH is currently offered at UCHealth primary care clinics in Colorado and Wyoming. Patients can contact their clinic to learn more or to schedule a weight-prioritized visit.


Center for Disease Control and Prevention (CDC). Overweight & Obesity (https://www.cdc.gov/obesity/index.html)

National Heart, Lung, and Blood Institute (NHLBI). Overweight and Obesity – What Are Overweight and Obesity? (https://www.nhlbi.nih.gov/health/overweight-and-obesity)