Obesity is defined as having an excessive amount of body fat that increases the risk of medical illnesses and premature mortality. A person's weight is largely determined by the balance between calories consumed and calories utilized by the body. Obesity occurs when a person consumes more calories than their body burns over time.
The most commonly used method to estimate obesity and determine one's ideal body weight is body mass index (BMI). BMI is calculated using a person's height and weight. A BMI of 30 kg/m2 or higher is considered obese. A BMI between 25-30 kg/m2 is considered overweight.
Obesity leads to impaired functioning and ill health for individuals and is a major public health challenge. Excess body fat puts strain on the bones, muscles, and organ systems including the heart and lungs. Obesity is a well-established risk factor for conditions including type 2 diabetes, high blood pressure, heart disease, stroke, and some types of cancers.
Causes of obesity are complex and include genetic, biological, behavioral, and environmental factors. Key contributors are unhealthy dietary patterns, lack of physical activity, increased sedentary behaviors, medications, sleep deprivation, genetics, aging, pregnancy, quitting smoking, and medical problems. Socioeconomic factors and food marketing also play a role.
Treatment of obesity focuses on lifestyle changes to achieve sustained weight loss and improve health. This includes adopting healthy eating habits with more vegetables, fruits and whole grains while limiting processed foods, sugars, and unhealthy fats. Regular physical activity for 150-300 minutes per week is also crucial. For some individuals, anti-obesity medications, weight loss surgery or medical devices may be considered alongside lifestyle modifications.
Prevention of obesity centers on building healthy environments and communities that foster better diet quality and active living for people across their lifespan. Public health policies and partnerships between healthcare, government, the private sector and communities have an important role to play.
The key is to make step-by-step, maintainable changes that help each person achieve a healthy weight and lifestyle over the long term. Small goals to increase daily movement and build healthy eating habits can go a long way. Support from professionals, family and friends is helpful for success. Overall we must address obesity compassionately and systematically - it is not just a personal responsibility but requires social and environmental change.