Being overweight or obese can lead to a number of health problems. Carrying excess weight puts extra strain on the body and can cause inflammation, which is linked to chronic diseases like heart disease, diabetes, and cancer. Understanding the health risks associated with being overweight or obese can help motivate lifestyle changes to achieve a healthy weight.
Obesity
Obesity is defined as having excess body fat. A person is considered obese when their body mass index (BMI) is 30 or higher. BMI is a measurement of body fat calculated by dividing a person’s weight in kilograms by the square of their height in meters. For adults 20 years old and older, the following BMI ranges apply:
| BMI | Weight Status |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Normal or Healthy Weight |
| 25.0 – 29.9 | Overweight |
| 30.0 and Above | Obese |
Someone with a BMI between 25 and 29.9 is considered overweight, while a BMI of 30 or more is considered obese. A BMI over 40 is considered morbidly obese.
The most common causes of obesity include:
- Consuming more calories than your body burns through activity and normal functioning
- Genetics and family history
- Medications that can cause weight gain as a side effect
- Health conditions like hypothyroidism and Cushing’s syndrome
- Lack of sleep
- Stress
- Pregnancy
Obesity increases the risk for many health problems, including:
- Heart disease and stroke
- High blood pressure
- Diabetes
- Cancer
- Gallbladder disease
- Osteoarthritis
- Gout
- Breathing problems like sleep apnea
Heart Disease
Being overweight stresses the cardiovascular system, putting obese individuals at greater risk of heart disease. Excess weight contributes to issues like:
- Atherosclerosis – Hardening and narrowing of arteries due to plaque buildup
- High cholesterol and triglycerides
- High blood pressure
- Heart attack
- Stroke
- Heart failure
- Arrhythmia or irregular heart beats
The more overweight someone is, the higher their risk of developing heart disease. However, even modest weight loss can help reduce cardiovascular risks. Losing just 5-10% of your body weight and keeping it off can significantly improve blood pressure, cholesterol, and blood sugar levels.
High Blood Pressure
Blood pressure rises as weight increases. Extra body fat requires more blood flow to supply oxygen and nutrients, which puts strain on blood vessel walls. Over time, the force of blood pushing against arteries can cause damage. High blood pressure, also called hypertension, occurs when blood flows through arteries at higher than normal pressures.
Blood pressure readings consist of two numbers – systolic pressure (pressure in blood vessels when the heart beats) and diastolic pressure (pressure when the heart is at rest between beats). Normal blood pressure is less than 120/80 mmHg. High blood pressure is defined as:
- Systolic between 130-139 or diastolic between 80-89 (Stage 1 Hypertension)
- Systolic at least 140 or diastolic at least 90 (Stage 2 Hypertension)
High blood pressure typically does not cause noticeable symptoms. Over time, uncontrolled high blood pressure can lead to health issues like:
- Stroke
- Heart attack
- Heart failure
- Kidney disease
- Blindness
- Cognitive decline
Maintaining a healthy weight is critical for controlling blood pressure. Even a small amount of weight loss can make a big difference in lowering hypertension risk.
Type 2 Diabetes
Type 2 diabetes occurs when the body becomes resistant to the effects of insulin or does not make enough insulin. Insulin is necessary for transporting blood sugar from the bloodstream into the body’s cells to be used for energy. Obesity is one of the primary risk factors for developing type 2 diabetes, accounting for around 90% of cases. Fat cells release hormones and other substances that impair the body’s ability to respond to insulin. Excess weight also stresses the insulin-producing cells in the pancreas.
Some signs and symptoms of type 2 diabetes include:
- Frequent urination
- Increased thirst
- Fatigue
- Blurred vision
- Slow healing cuts/sores
- Tingling or numbness in hands or feet
Consistently high blood sugar levels in uncontrolled diabetes can irreversibly damage organs like the kidneys, eyes, heart, nerves, and blood vessels. However, type 2 diabetes can often be improved or reversed through weight loss, diet, exercise, and sometimes medication or insulin therapy.
Fatty Liver Disease
Non-alcoholic fatty liver disease (NAFLD) involves fat accumulation in the liver without excessive alcohol use. It ranges from simple fatty liver, which is usually harmless, to nonalcoholic steatohepatitis (NASH) which can progress to liver scarring, cirrhosis, and liver cancer. Obesity and metabolic syndrome are strongly associated with NAFLD and NASH.
Fatty liver disease often has no symptoms. When present, symptoms may include:
- Fatigue
- Weakness
- Weight loss
- Loss of appetite
- Abdominal discomfort
- Confusion
There are no approved medical treatments for NAFLD. Weight loss through diet and exercise is the primary recommendation to improve fatty liver disease. Just a 5-10% reduction in body weight can significantly decrease fat levels in the liver.
Gallbladder Disease
The gallbladder stores and releases bile to aid digestion. Gallbladder disease occurs when bile hardens into stones, a condition known as cholelithiasis. Rapid weight loss and obesity are risk factors for developing gallstones. Carrying excess weight may affect how the gallbladder contracts and release bile. Additionally, obesity can increase cholesterol levels in bile, leading to stone formation.
Symptoms of gallstones include:
- Sudden, intense abdominal pain (biliary colic)
- Nausea and vomiting
- Fever
- Yellowing of skin and eyes (jaundice)
- Light colored stools
Losing weight gradually through diet and exercise may help prevent gallstones in overweight individuals. However, rapid weight loss through very low calorie diets can actually increase gallstone risk. A balanced, moderate approach to weight management is recommended.
Respiratory Problems
Excess weight on the chest and abdomen can restrict breathing by limiting diaphragm expansion. This may lead to respiratory issues like:
- Asthma – Being overweight exacerbates asthma symptoms and decreases lung function.
- Sleep apnea – This involves paused breathing during sleep due to upper airway obstruction. Obesity raises risk of sleep apnea.
- Pickwickian syndrome – A severe condition involving obesity, daytime drowsiness, and heart failure due to fluid buildup in lungs.
Even modest weight loss can relieve symptoms of asthma and sleep apnea. For severe or refractory cases, treatment may involve use of a CPAP machine, oxygen therapy, or surgery.
Musculoskeletal Disorders
Carrying excess pounds strains the bones, joints, and connective tissues. This can lead to or worsen conditions like:
- Osteoarthritis – Breakdown of joint cartilage causing pain, swelling, and stiffness, especially in knees.
- Gout – Painful form of arthritis caused by uric acid crystal buildup in joints.
- Low back pain – Extra weight and strain on the spine contributes to back pain and injury risk.
Losing weight reduces mechanical stress throughout the body, lowering odds of developing musculoskeletal conditions and often relieving related pain. This allows for greater mobility, flexibility, and improved quality of life.
Increased Cancer Risk
Being overweight raises the likelihood of developing certain cancers, especially:
- Breast (postmenopausal)
- Colon
- Endometrial (lining of the uterus)
- Kidney
- Esophageal
- Pancreatic
Fat cells may directly influence tumor growth by producing hormones like estrogen. Excess weight also often causes inflammation, which can promote development of cancer. Losing even a moderate amount of weight can significantly lower cancer risk.
Reproductive Issues
Obesity can negatively impact fertility and reproductive health in both women and men. In women, excess body fat is linked to conditions like:
- Irregular menstruation
- Chronic anovulation (lack of ovulation)
- Polycystic ovarian syndrome (PCOS)
- Infertility
- Complications during pregnancy
Overweight men may experience lowered sperm count, erectile dysfunction, and other issues. Losing 5-10% of weight can help restore regular ovulation and improve chances of pregnancy.
Psychological Effects
Being overweight or obese can take a toll on emotional health and wellbeing. Excess weight is associated with:
- Depression
- Anxiety
- Low self-esteem
- Body image dissatisfaction
- Social isolation and loneliness
Weight stigma and bullying worsens psychological distress. Losing weight can improve self-image. However, it’s important to find self-worth beyond just body size.
Increased Medication Dosages
Some drugs like blood pressure and diabetes medications have dosage guidelines based on weight. Someone who is obese may require higher than normal doses to get therapeutic effects. Carrying excess fat can also alter how medications are distributed and broken down in the body. Losing weight may allow patients to be effectively treated with lower drug doses.
Decreased Quality of Life
The health conditions associated with obesity can severely impact daily functioning and quality of life. Excess weight can make it hard to be mobile, walk distances, fit into spaces, perform tasks, sleep comfortably, engage in hobbies, and interact socially. This contributes to loss of independence and social isolation. Even modest weight loss can dramatically improve mobility, sleep quality, and ability to participate in desired activities.
Increased Mortality
Obesity notably raises the risk of dying at a younger age from health issues. Compared to normal weight individuals, obesity is associated with:
- 50-150% increased risk of premature death overall
- 2-3 times greater risk of heart disease mortality
- 2 times greater risk of cancer mortality
However, studies show weight loss significantly decreases mortality rates, especially when combined with exercise. Losing just 5-10% of body weight can add years to life expectancy.
Conclusion
Carrying excess body fat can negatively impact nearly every aspect of health. Obesity raises the likelihood of chronic diseases like diabetes, heart disease, cancer, and more. It also worsens mental health, quality of life, reproductive health, and longevity. However, even a 5-10% reduction in body weight can dramatically lower disease risks and extend lifespan. Losing weight through balanced diet and regular exercise is one of the most effective ways to prevent and control many medical conditions.