Diverse diagnostic criteria for obesity: BMI, body fat percentage, waist-to-hip ratio, and metabolic risk assessment.

Common indicators for diagnosing obesity include Body Mass Index (BMI), body fat percentage, waist circumference, and waist-to-hip ratio. BMI is calculated based on the relationship between weight and height, using the formula: weight divided by the square of height (kg/m²). According to the diagnostic criteria for overweight and obesity based on BMI, a BMI below 18.5 is considered underweight, 18.5 to 23.9 is considered normal, and 24.0 to 27.9 is considered overweight. A BMI above 28 is considered obese, with 28.0 to 35.0 indicating mild obesity, 35.0 to 40.0 indicating moderate obesity, and a BMI above 40 indicating severe obesity.

For Asians, these standards provide a generally accepted reference. Body fat percentage reflects the amount of fat in the body and is the best indicator for assessing overweight and obesity. Generally, a body fat percentage of 10% to 20% is considered normal for men, while over 20% indicates overweight or obesity; for women, the normal range is 15% to 25%, and over 25% indicates overweight or obesity. Specifically, 25% to 30% is overweight, 30% to 35% is mildly obese, 35% to 40% is moderately obese, a body fat percentage greater than 40% is severely obese, and over 50% is considered extremely obese.

There are two main methods for measuring body fat percentage: one is the skinfold thickness method, which is both simple and economical. This method involves measuring the skinfold thickness below the inferior angle of the scapula and at the midpoint of the outer side of the upper arm using skinfold calipers, substituting the result into a specific formula to obtain body density, and then calculating the body fat percentage. The other method is instrumental measurement, which can be performed at a professional institution. Waist circumference and waist-to-hip ratio reflect the accumulation of subcutaneous and visceral fat in the abdomen and are simple indicators for measuring abdominal obesity. A waist circumference of 85 cm or more for men and 80 cm or more for women is considered obese.

For the waist-to-hip ratio, a ratio of 0.9 or higher for men and 0.85 or higher for women is considered relatively accurate in assessing abdominal obesity. Each diagnostic method for different degrees of obesity has its own advantages and disadvantages; currently, there is no ideal method that is both simple and accurate. Therefore, a comprehensive approach should be taken during diagnosis. Scientific research shows that obesity is a disease caused by specific biochemical factors, resulting in a series of disorders in food intake regulation and energy metabolism, and its pathogenesis is complex. A World Health Organization survey indicates that the number of obese people in China has reached 325 million, and obesity has seriously endangered human health.

Obesity, along with cancer and acquired immunodeficiency, is considered one of the three major diseases threatening human health. Obesity not only alters physical appearance but also severely impacts mental health. Obese individuals typically experience physical discomfort, heat intolerance, excessive sweating, and fatigue; in severe cases, they may suffer from mobility issues, difficulty with daily living, low self-esteem, and depression. Due to excessive fat accumulation, various bodily functions decline, leading to a range of metabolic diseases associated with obesity.

Obesity is a chronic metabolic disease caused by excessive accumulation of body fat. Obese patients often suffer from metabolic disorders, especially disorders of glucose and lipid metabolism. Metabolic syndrome caused by obesity seriously endangers health. Numerous studies have found that childhood and adolescent obesity increases their risk of obesity in adulthood. 75% to 80% of obese adolescents remain obese in adulthood and are prone to developing type 2 diabetes, significantly increasing their risk of hypertension, fatty liver, atherosclerosis, and coronary heart disease.

Experts point out that the development of fatty liver disease is closely related to obesity. Obesity is the main cause of fatty liver disease in obese patients, accounting for 75.43% of all cases. Effectively controlling weight to a normal range can significantly reduce the risk of developing fatty liver disease. Obese women are prone to menstrual disorders, polycystic ovary syndrome, infertility, and have a higher miscarriage rate. Obese pregnant women are more likely to suffer from hypertension, preeclampsia, and gestational diabetes; their fetal mortality rate is three times that of women of normal weight.

In addition, obesity is closely related to the occurrence of certain cancers, such as colon cancer and prostate cancer in men, and endometrial cancer and breast cancer in women. Obesity assessment is also a commonly used method. Obesity is calculated as the percentage obtained by subtracting the standard weight from the measured weight and then dividing by the standard weight. An obesity percentage below -20% is considered underweight, below -10% is considered underweight, and between ±10% is considered normal. A percentage above 10% is considered overweight, 20% to 30% is considered mildly obese, 30% to 50% is considered moderately obese, and above 50% is considered severely obese.

When developing a weight loss plan, a comprehensive evaluation based on the above-mentioned diverse indicators should be conducted to ensure the scientific validity and safety of the plan.