Not that long ago, obesity was considered a cosmetic condition that only impacted a person’s appearance. We now know that obesity affects a person’s health in profound and serious ways, contributing to the development of type 2 diabetes and certain cancers. (14) That’s why several prominent organizations, such as the American Medical Association, the Canadian Medical Association, and the World Health Organization, classify it as a disease with its own ICD-10 code. This International Classification of Diseases code represents that obesity can be considered a cause of death. (4)
The rates of obesity continue to increase, making it imperative to understand and address this health condition. According to the non-profit organization Trust for America’s Health, obesity rates are now at historic highs with one in three Americans of all ages being classified as obese. (17)
What is obesity?
The terms overweight and obese are often used interchangeably. Both refer to body weight that is greater than what is considered healthy for a certain height. (13) Body mass index (BMI) is a measurement often used to determine if someone is obese or overweight.
BMI is calculated by dividing the amount someone weighs in pounds by height in inches squared and then multiplying that by 703. For example, a person who weighs 125 pounds and is five feet tall would have a BMI of 24.4, which is in the normal range.
Here is the classification for overweight and obesity based on BMI calculation:
- Underweight BMI = <18.5
- Normal BMI = 18.5–24.9
- Overweight BMI = 25.0–29.9
- Obese BMI = 30.0–39.9
- Severely obese BMI = ≥40 (7)
Based on this classification, severe obesity, the most dangerous form, is defined as a BMI of 40 or higher. It’s important to note that BMI is a screening tool and not all individuals with an elevated BMI are considered overweight or obese. Age, ethnicity, muscle mass, and sex can impact the accuracy of results. (3)

Obesity health problems
There are numerous health risks associated with obesity. That’s because carrying extra weight can lead to insulin resistance and increased inflammation, both of which are linked to many illnesses, such as cancer, heart disease, and type 2 diabetes. (15)
Obesity and type 2 diabetes
Obesity is the leading risk factor for type 2 diabetes. (1) A 2014 study that followed nearly 34,000 young individuals with an average age of about 31 found that being overweight or obese significantly increased the risk of type 2 diabetes. These individuals had no other signs or risk factors for diabetes other than the extra weight. (18) Other large epidemiological studies have revealed similar results, finding that as body fat levels rise, so does insulin resistance.
Obesity and cancer
The research regarding the link between obesity and cancer is growing. Obesity is now causally linked to 13 different types of cancer, including breast, colon, ovarian, uterine, pancreatic, and several others. (8) Losing weight or maintaining a healthy body weight could potentially reduce the risk of developing certain cancers. (16)
Obesity and heart disease
When it comes to obesity and heart disease, there’s no debate. Obesity is linked to an increased risk of developing heart disease, specifically heart failure and coronary heart disease. (2) Even if there are no other risk factors such as smoking, stress, high cholesterol or high blood pressure, just carrying extra weight may lead to heart disease. (5)
Obesity risk factors
Given the significant health issues associated with obesity, understanding how to prevent it should be a top priority for everyone. Looking at what causes obesity is the first step towards proactive prevention. According to the National Heart, Lung, and Blood Institute (NHLBI), there are several known causes of obesity, including:
- Energy imbalances which occur when there is more incoming energy in the form of calories and not enough energy going out in the form of physical activity
- Genetic obesity such as Prader-Willi syndrome, Bardet-Biedl syndrome, and others
- Endocrine disorders such as hypothyroidism, Cushing’s syndrome, and tumors
- Medications such as antidepressants, antiepileptics, and others (11)
The NHLBI also reports that four key lifestyle factors can increase the risk of obesity:
- High amounts of stress
- Inadequate sleep
- Lack of physical activity
- Unhealthy eating habits (11)
How to prevent obesity
Based on the previously mentioned four lifestyle factors, everyone who is interested in preventing obesity or losing weight should focus on:
1. Being physically active
Everyone can benefit from regular physical activity. Exercise supports brain health, longevity, and weight management. Following the Centers for Disease Control and Prevention’s (CDC) recommendation of at least 150 minutes a week of moderate-intensity exercise can also reduce the risk of developing certain cancers, heart disease, and type 2 diabetes. (6) Moderate-intensity aerobic activity, such as brisk walking, is generally safe for most people; however, if you’re a patient, be sure to consult with your integrative practitioner before starting a new fitness regimen.

2. Eating a healthy, whole food diet
Healthy eating can promote weight management and prevent obesity-related complications. Research shows that dietary patterns that include a relatively higher intake of whole foods, such as fruits, vegetables, legumes, and whole grains, as well as low or nonfat dairy, lean meats and poultry, seafood, nuts, and unsaturated fats are associated with positive health outcomes. (19) Dietary patterns such as the DASH diet and Mediterranean diet emphasize the intake of these wholesome foods.
The Dietary Guidelines for Americans recommends making every bite count by choosing to eat a variety of fruits, vegetables, grains, dairy or fortified soy alternatives, and protein foods. Whole, nutrient-dense foods and beverages provide health-promoting vitamins and minerals with little added sugars, saturatedfat, and sodium. (19)
3. Getting adequate sleep
Although sleep needs vary by individual, the American Academy of Sleep Medicine (AASM) recommends that adults receive about seven to eight hours of sleep each night. Sleep supports brain function and physical health and lack of sleep may impair decision-making, problem solving, and emotional regulation. Chronic sleep deficiency increases the risk of obesity and is linked to an increased risk of cardiovascular disease, chronic kidney disease, and type 2 diabetes. (12)
In a study of teenagers, correlation was observed between sleep loss and obesity. As more sleep was lost, the odds of becoming obese increased. The NHLBI also states that studies show inadequate sleep is associated with alterations in hormones associated with energy balance, such as ghrelin and leptin. Ghrelin stimulates appetite and hunger, while leptin signals satiety. Lack of sleep has been shown to cause a rise in ghrelin levels and a decrease of leptin, potentially leading to excess caloric intake. (12)
4. Practicing proactive stress management
Studies show that exposure to chronic stress is associated with a greater risk of obesity. Little is known about the mechanisms of stress-induced obesity, but findings suggest that inflammation may play a role. (9) Practicing healthy stress management techniques can improve mental and physical wellbeing. Possible ways to manage stress include:
- Breathing exercises
- Meditation
- Physical activity
- Talking to others (10)
The bottom line
Maintaining a healthy body weight is something everyone should be focused on—our health depends on it! Understanding risk factors and taking proactive steps to prevent obesity or lose weight will reduce the risk of many illnesses including the top three killers of our time: diabetes, cancer, and heart disease.
- Barnes, A. S. (2011). The epidemic of obesity and diabetes: Trends and treatments. Texas Heart Institute Journal / from the Texas Heart Institute of St. Luke’s Episcopal Hospital, Texas Children’s Hospital, 38(2), 142–144.
- Carbone, S., Canada, J. M., Billingsley, H. E., Siddiqui, M. S., Elagizi, A., & Lavie, C. J. (2019). Obesity paradox in cardiovascular disease: Where do we stand? Vascular Health and Risk Management, 15, 89–100.
- CDC. (n.d.). Body mass index: Considerations for practitioners. https://www.cdc.gov/obesity/downloads/bmiforpactitioners.pdf
- CDC. (2015). International Classification of Diseases (ICD-10). https://www.cdc.gov/nchs/icd/icd10cm_pcs_background.htm
- CDC. (2019). Know your risk for heart disease. https://www.cdc.gov/heartdisease/risk_factors.htm
- CDC. (2021a). Benefits of physical activity. https://www.cdc.gov/physicalactivity/basics/pa-health/index.htm
- CDC. (2021b). Defining adult overweight & obesity. https://www.cdc.gov/obesity/adult/defining.html
- Colditz, G. A., & Peterson, L. L. (2018). Obesity and cancer: Evidence, impact, and future directions. Clinical Chemistry, 64(1), 154–162.
- Hamer, M., & Stamatakis, E. (2008). Inflammation as an intermediate pathway in the association between psychosocial stress and obesity. Physiology & Behavior, 94(4), 536–539.
- NHLBI. (n.d.-a). Heart-healthy living. https://www.nhlbi.nih.gov/health-topics/heart-healthy-living
- NHLBI. (n.d.-b). Overweight and obesity. https://www.nhlbi.nih.gov/health-topics/overweight-and-obesity
- NHLBI. (n.d.-c). Sleep deprivation and deficiency. https://www.nhlbi.nih.gov/health-topics/sleep-deprivation-and-deficiency
- NIDDK. (2018). Definition & facts for adult overweight & obesity. https://www.niddk.nih.gov/health-information/weight-management/adult-overweight-obesity/definition-facts
- Pi-Sunyer, F. X. (1999). Comorbidities of overweight and obesity: Current evidence and research issues. Medicine and Science in Sports and Exercise, 31(11 Suppl), S602–S608.
- Redinger, R. N. (2007). The pathophysiology of obesity and its clinical manifestations. Gastroenterology & Hepatology, 3(11), 856–863.
- The American Cancer Society. (2020). Does body weight affect cancer risk? https://www.cancer.org/cancer/cancer-causes/diet-physical-activity/body-weight-and-cancer-risk/effects.html
Trust for America’s Health. (2019). U.S. obesity rates reach historic highs – racial, ethnic, gender and geographic disparities continue to persist. https://www.tfah.org/report-details/stateofobesity2019/ - Twig, G., Afek, A., Derazne, E., Tzur, D., Cukierman-Yaffe, T., Gerstein, H. C., & Tirosh, A. (2014). Diabetes risk among overweight and obese metabolically healthy young adults. Diabetes Care, 37(11), 2989–2995.
- USDA. (2020). Dietary Guidelines for Americans. https://www.dietaryguidelines.gov/