General Information for Obesity

Overweight and obesity are defined as abnormal or excessive fat accumulation in the body. Obesity is regarded as a chronic disease and its treatment demands lifelong efforts.

Obesity is a growing pandemic. In 2008, more than 1.4 billion adults worldwide were overweight. Of these, over 200 million men and nearly 300 million women were obese. What appears to be especially worrisome is that rates of childhood obesity are on the increase.

Body mass index (BMI) is a rough guide to identify overweight and obese people. It is calculated by dividing one’s weight in kilograms by the square of one’s height in meters (kg/m²). However, it may overestimate the degree of fatness in muscular patients and underestimate in people who have lost body mass (eg. the elderly). The classification according to BMI values is as follows:

• BMI 25-29.9: overweight
• BMI 30-34.9: class I obese
• BMI 35-39.9: class II obese
• BMI ≥40: class III obese (extreme/morbid obesity)

Waist circumference helps in assessing body fat distribution. Values >88 cm (35 in) for women and >102 cm (>40 in) for men indicate a higher risk for diabetes, dyslipidemia, hypertension, and cardiovascular disease in people independently of BMI.

Being obese can lead to serious health problems, as well as shorten the life expectancy. It is estimated that more than 2.8 million adults die each year as a result of being overweight or obese. Except from premature deaths, obesity also increases the risk of multiple health problems such as hypertension, type 2 diabetes, dyslipidemia, heart disease, stroke, cancers (endometrial, breast, colon), osteoarthritis, back pain, depression, liver disease (fatty-liver), kidney disease, sleep apnea (interrupted breathing during sleep), gastro-oesophageal reflux disease, gallbladder disease, respiratory problems, complications in pregnancy, infertility, fungal skin infections, vein insufficiency of legs, thromboembolic events, stress incontinence, poor quality of life and psychological disorders (depression, eating disorders, distorted body image, and low self-esteem). The greater the BMI, the greater the risk of complications.

The overweight/obesity derives from the energy imbalance between calories consumed and calories expended mainly attributed to the increased intake of energy-dense, fatty foods and the increase in sedentary lifestyle. Genetic background may predispose to the appearance of obesity.

Nowadays, childhood obesity is considered an alarming public health concern as the number of overweight/obese children mainly in developed countries is increasing. These children are at high risk to become overweight/obese adolescents and adults later in life and develop serious obesity-related health problems or die prematurely. The main causes for this epidemic are the changes in modern lifestyle (unhealthy eating patterns, sedentary life mainly due to the increased time spent sitting in front of TV or PC screens) that contribute in energy imbalance. In addition, genetic factors and family characteristics have been shown to play a major role. The diagnosis of overweight/obesity in children is also based on BMI values. However, normal range varies with age and sex and there are special tables for determining this in children.

Abdominal obesity is one of the cardiovascular risk factors. More specifically risk factors for cardiovascular disease are:

• Age (men ≥45 years old, women ≥55 years old or postmenopausal)
• Smoking
• Hypertension
• Dyslipidemia (elevated LDL, low HDL, high TG)
• Diabetes/prediabetes
• Elevated waist circumference [>102 cm (>40 in) for men and >88 cm (35 in) for women]
• Family history of premature coronary heart disease (men 55 years old, women 65 years old)
• Physical inactivity

The main obesity-related diseases are the following:

• Established coronary heart disease [myocardial infraction, angina, coronary artery surgery/procedure (eg. angioplasty)]
• Atherosclerotic disease (peripheral artery disease, abdominal aortic aneurysm, carotid artery disease)
• Sleep apnea (interrupted breathing during sleep)
• Gynecological abnormalities (menstruation disorders)
• Osteoarthritis
• Gallstones and complications
• Stress incontinence

You need to lose weight if you are obese (BMI ≥30) or overweight (BMI 25-29.9) with 1 or more additional risk factors for cardiovascular disease or other obesity-related diseases.Remember that the first goal is to prevent further weight gain and keep body weight stable.

The rate of weight loss depends upon several factors, such as age, gender, and baseline weight (ie. young people, men, extremely overweight people lose weight more quickly). Generally speaking, a realistic weight loss goal is that of 5% to 10% of baseline weight within 6 months. The rate of weight loss should be 450-900 gr (1 to 2 pounds) each week. Greater rates are not desirable because these do not achieve better long-term results.

Sustained weight loss of 3%-5% is likely to result in clinically meaningful reductions in triglycerides, blood glucose, and the risk of developing diabetes mellitus. Greater amounts of weight loss will reduce blood pressure levels, improve lipid profile (decrease in LDL and increase in HDL), and reduce the need for medications to control blood pressure, blood glucose and lipids.

An optimal program for weight loss starts with a combination of diet, exercise, and behavioral modification. In addition, some patients eventually require medications or weight loss surgery.

Weight loss requires creating an energy deficit through caloric restriction, physical activity, or usually both.

Reduced-calorie diet: A diet designed to create an energy deficit >500 kcal/day. Dietary intake of 1.200 to 1.500 kcal/day for women and 1.500 to 1.800 kcal/day for men.

Increased physical activity: Increased aerobic physical activity (such as brisk walking, jogging, cycling) for ≥150 min/week (equal to ≥30 min/day, most days of the week).

Behavioral modification: Regular self-monitoring of food intake, physical activity, and weight.