According to the World Health Organisation (WHO) (2020), overweight and obesity are defined as abnormal or excessive fat accumulation that may impair health. For adults, WHO defines overweight is a BMI greater than or equal to 25 and obesity is a BMI greater than or equal to 30. For children less than 5 years of age overweight is weight-for-height greater than 2 standard deviations above WHO Child Growth Standards median; and obesity is weight-for-height greater than 3 standard deviations above the WHO Child Growth Standards median. For children aged between 5–19 years overweight is BMI-for-age greater than 1 standard deviation above the WHO Growth Reference median; and obesity is greater than 2 standard deviations above the WHO Growth Reference median.
Balentine (2019) described obesity is a chronic condition defined by an excess amount of body fat. He however clarified that the body mass index (BMI) best defines obesity. A person’s height and weight determines his or her body mass index. The body mass index (BMI) equals a person’s weight in kilograms (kg) divided by their height in meters (m) squared. Since BMI describes body weight relative to height, there is a strong correlation with total body fat content in adults. An adult who has a BMI of 25-29.9 is overweight, and an adult who has a BMI over 30 is obese. A person with a BMI of 18.5-24.9 has a normal weight. A person is morbidly obese (extreme obesity) if his or her BMI is over 40.
Obesity is a complex disease involving an excessive amount of body fat. Obesity isn’t just a cosmetic concern. It is a medical problem that increases your risk of other diseases and health problems, such as heart disease, diabetes, high blood pressure and certain cancers. There are many reasons why some people have difficulty avoiding obesity. Usually, obesity results from a combination of inherited factors, combined with the environment and personal diet and exercise choices. The good news is that even modest weight loss can improve or prevent the health problems associated with obesity. Dietary changes, increased physical activity and behavior changes can help you lose weight. Prescription medications and weight-loss procedures are additional options for treating obesity (Mayo Clinic, 2020).
Prevalence of Overweight and Obesity
WHO (2020) global estimates reveal that in 2016, more than 1.9 billion adults aged 18 years and older were overweight. Of these over 650 million adults were obese. 39% of adults aged 18 years and over (39% of men and 40% of women) were overweight. Overall, about 13% of the world’s adult population (11% of men and 15% of women) was obese. The worldwide prevalence of obesity nearly tripled between 1975 and 2016. In 2019, an estimated 38.2 million children under the age of 5 years were overweight or obese. Once considered a high-income country problem, overweight and obesity are now on the rise in low- and middle-income countries, particularly in urban settings.
The National Center for Health Statistics (NCHS) estimates that, for 2015–2016 in the U.S., 39.8% of adults aged 20 and over were obese (including 7.6% with severe obesity) and that another 31.8% were overweight (Cheryl, Margaret & Cynthia, 2018). In the NCHS update for 2018, statistics on severe obesity among U.S adults had already climbed to 9.2% while the total obesity prevalence had reached 42.4%. This also marked the first time in American history that the obesity rates had reached or exceeded 2/5 people in every adult age groups (Craig, Margaret, Cheryl & Cynthia, 2020).
Blackburn and Walker (2005) noted that obesity rates have increased for all population groups in the United States over the last several decades. Between 1986 and 2000, the prevalence of severe obesity (BMI ≥ 40 kg/m2) quadrupled from one in two hundred Americans to one in fifty. Extreme obesity (BMI ≥ 50 kg/m2) in adults increased by a factor of five, from one in two thousand to one in four hundred. There have been similar increases seen in children and adolescents, with the prevalence of overweight in pediatric age groups nearly tripling over the same period. Approximately nine million children over six years of age are considered obese. Several recent studies have shown that the rise in obesity in the US is slowing, possibly explained by saturation of health-oriented media (Jeannine, 2010).
According to Guillermo (2021), in 2014, more than 300 million adults in Latin America, were overweight. Of these more than 100 million were obese. Around 57% (302 million) of the region’s adult population (54% men and 70% of women) are overweight, and 19% (100.8 million) are obese (14.6% in men and 24% in women). Fourteen countries in Latin America have a female prevalence greater than 20%. The highest prevalence of obesity in the adult population is found in El Salvador (33%) and Paraguay (30.1%) for women and in Uruguay (23.3%) and Chile (22.0%) for men. The prevalence of overweight and obesity in Latin American children is also remarkably high (16%). It ranges from more than 12% for girls in Chile, Uruguay and Costa Rica to less than 5% in Bolivia, Ecuador, Peru, Honduras, and Guatemala. The highest prevalence of obesity in children is found in Chile (11.9%) and Mexico (10.5%) in boys, and in Uruguay (18.1%,) and Costa Rica (12.4%) in girls (Ng, Fleming, Robinson, Thomsom, Graetz, et al., 2014).
Despite the fact that obesity and overweight is a problem of high-income countries —particularly in urban settings and sub-Saharan African countries—face the challenge of an increasing trend. Adom, Puoane, De Villiers, et al., (2017) noted that in Sub-Saharan Africa, in 2014 more than 1.9 billion adults aged 18 years and older were overweight. The number of children who are overweight or obese has nearly doubled from 5.4 million in 1990 to 10.6 million in 2014.
According to country estimates for 2008, over 50% of both men and women in the WHO European Region were overweight, and roughly 23% of women and 20% of men were obese. Overweight affects 30-70% and obesity affects 10-30% of adults. Estimates of the number of overweight infants and children in the WHO European Region rose steadily from 1990 to 2008. Over 60% of children who are overweight before puberty will be overweight in early adulthood (WHO, 2008).
Wan (2014) stated that although Asian countries have some of the lowest prevalence of overweight and obesity worldwide, they are experiencing alarming rates of increase in recent years. The boom in economic development and cultural factors are often cited as drivers. Vietnam and India have the lowest rates of obesity in Asia Pacific (1.7 % and 1.9 % respectively). Malaysia has the highest obesity prevalence at 14 % in the South East Asia region, with Thailand next in line (8.8 %). These figures fall far behind those in the Oceanic countries, with 26.8 % obesity rates in Australia and 28.3 % in New Zealand. The prevalence of obesity in these countries is similar to rates seen in the United Kingdom (26.9 %) and US (33 %). Between 1980 and 2013, China’s overweight and obesity prevalence in adults rose from 11.3 % to 27.9 % and in individuals below age 20 from 5.7 % to 18.8 % [Institute for Health Metrics and Evaluation (IHME), (2014)]. Malaysia saw a three-fold increase in obesity prevalence among adults, from 4.4 % in 1996 to 14 % in 2006 (Khor, 2012). Likewise, overweight and obesity prevalence among adults in Vietnam more than doubled from 1992 to 2002 (2.0 % to 5.7 %) (Tuan, Tuong & Popkin, 2007).
Contributing Factors to Overweight and Obesity
Balentine (2019) in highlighting the major causes of overweight and obesity stated that the balance between calorie intake and energy expenditure determines a person’s weight. If a person eats more calories than he or she burns (metabolizes), the person gains weight (the body will store the excess energy as fat). If a person eats fewer calories than he or she metabolizes, he or she will lose weight. Therefore, the most common causes of obesity are overeating and physical inactivity. Ultimately, body weight is the result of genetics, metabolism, environment, behavior, and culture.
- Physical Inactivity: Sedentary people burn fewer calories than people who are active. The National Health and Nutrition Examination Survey (NHANES) showed a strong correlation between physical inactivity and weight gain in both sexes (Balentine, 2019).
- Overeating: Overeating leads to weight gain, especially if the diet is high in fat. Foods high in fat or sugar (for example, fast food, fried food, and sweets) have high energy density (foods that have a lot of calories in a small amount of food). Epidemiologic studies have shown that diets high in fat contribute to weight gain (Balentine, 2019).
- Genetics: A person is more likely to develop obesity if one or both parents are obese. Genetics also affect hormones involved in fat regulation. For example, one genetic cause of obesity is leptin deficiency. Leptin is a hormone produced in fat cells and in the placenta. Leptin controls weight by signaling the brain to eat less when body fat stores are too high. If, for some reason, the body cannot produce enough leptin or leptin cannot signal the brain to eat less, this control is lost, and obesity occurs. The role of leptin replacement as a treatment for obesity is under exploration (Balentine, 2019).
- A Diet High in Simple Carbohydrates: The role of carbohydrates in weight gain is not clear. Carbohydrates increase blood glucose levels, which in turn stimulate insulin release by the pancreas, and insulin promotes the growth of fat tissue and can cause weight gain. Some scientists believe that simple carbohydrates (sugars, fructose, desserts, soft drinks, beer, wine, etc.) contribute to weight gain because they are more rapidly absorbed into the bloodstream than complex carbohydrates (pasta, brown rice, grains, vegetables, raw fruits, etc.) and thus cause a more pronounced insulin release after meals than complex carbohydrates. This higher insulin release, some scientists believe, contributes to weight gain (Balentine, 2019).
- Frequency of Eating: The relationship between frequency of eating (how often you eat) and weight is somewhat controversial. There are many reports of overweight people eating less often than people with normal weight. Scientists have observed that people who eat small meals four or five times daily, have lower cholesterol levels and lower and/or more stable blood sugar levels than people who eat less frequently (two or three large meals daily). One possible explanation is that small frequent meals produce stable insulin levels, whereas large meals cause large spikes of insulin after meals (Balentine, 2019).
- Medications: Medications associated with weight gain include certain antidepressants (medications used in treating depression), anticonvulsants (medications used in controlling seizures such as carbamazepine [Tegretol, Tegretol XR , Equetro, Carbatrol] and valproate [Depacon, Depakene]), some diabetes medications (medications used in lowering blood sugar such as insulin, sulfonylureas, and thiazolidinediones), certain hormones such as oral contraceptives, and most corticosteroids such as prednisone. Some high blood pressure medications and antihistamines cause weight gain. The reason for the weight gain with the medications differs for each medication. If this is a concern for you, you should discuss your medications with your physician rather than discontinuing the medication, as this could have serious effects (Balentine, 2019).
- Psychological Factors: For some people, emotions influence eating habits. Many people eat excessively in response to emotions such as boredom, sadness, stress, or anger. While most overweight people have no more psychological disturbances than normal weight people, about 30% of the people who seek treatment for serious weight problems have difficulties with binge eating (Balentine, 2019).
- Diseases: Some diseases such as hypothyroidism, insulin resistance, polycystic ovary syndrome, and Cushing’s syndrome are also contributors to obesity. Some diseases, such as Prader-Willi syndrome, can lead to obesity (Balentine, 2019).
- Social issues: There is a link between social issues and obesity. Lack of money to purchase healthy foods or lack of safe places to walk or exercise can increase the risk of obesity (Balentine, 2019).
- Ethnicity: Ethnicity factors may influence the age of onset and the rapidity of weight gain. African-American women and Hispanic women tend to experience weight gain earlier in life than Caucasians and Asians, and age-adjusted obesity rates are higher in these groups. Non-Hispanic black men and Hispanic men have a higher obesity rate then non-Hispanic white men, but the difference in prevalence is significantly less than in women (Balentine, 2019).
- Childhood Weight: A person’s weight during childhood, the teenage years, and early adulthood may also influence the development of adult obesity. Therefore, decreasing the prevalence of childhood obesity is one of the areas to focus on in the fight against obesity. For example,
- being mildly overweight in the early 20s was linked to a substantial incidence of obesity by age 35;
- being overweight during older childhood is highly predictive of adult obesity, especially if a parent is also obese;
- being overweight during the teenage years is even a greater predictor of adult obesity.
- Hormones: Women tend to gain weight especially during certain events such as pregnancy, menopause, and in some cases, with the use of oral contraceptives. However, with the availability of the lower-dose estrogen pills, weight gain has not been as great a risk (Balentine, 2019).
Signs and Symptoms of Overweight and Obesity
According to Sherry (2019), signs and symptoms of overweight and obesity can be classified into frequent, morbid and rare symptoms.
For adults, frequent symptoms include:
- Excess body fat accumulation (particularly around the waist)
- Shortness of breath (Hruby & Hu, 2015).
- Sweating (more than usual)
- Trouble sleeping
- Skin problems (from moisture accumulating in the folds of skin)
- Inability to perform simple physical tasks (that one could easily perform before weight gain)
- Fatigue (from mild to extreme) (Hruby & Hu, 2015).
- Pain (commonly in the back and joints)
- Psychological impact (negative self-esteem, depression, shame, social isolation) (Değirmenci, Kalkan-oğuzhanoğlu, Sözeri-varma, Özdel & Fenkçi, 2015).
Frequent symptoms for overweight and obesity among children and adolescents include:
- Eating disorders
- Fatty tissue deposits (may be noticeable in the breast area)
- The appearance of stretch marks on the hips and back
- Acanthosis nigricans (dark velvety skin around the neck and other areas)
- Shortness of breath with physical activity (Xu & Xue, 2016).
- Sleep apnea (Xu & Xue, 2016).
- GI reflux
- Poor self-esteem (Xu & Xue, 2016).
- Early puberty in girls/delayed puberty in boys
- Orthopedic problems (such as flat feet or dislocated hips)
A person experiencing health conditions related to obesity (such as high blood pressure or diabetes) with a BMI of 35 or more, is also considered morbidly obese (Lozano, Tió, Rios, et al., 2015). Morbid obesity can cause a person to struggle with everyday activities such as walking and can impair bodily functions such as breathing. It also puts a person at high risk for many other serious health conditions.
Rare symptoms of overweight and obesity include:
- Pro-opiomelanocortin (POMC) Deficiency Obesity: Key symptoms include hyperphagia (extreme hunger) starting during infancy, early-onset obesity, and hormonal problems (such as adrenal insufficiency).
- Leptin receptor (LEPR) Deficiency Obesity: Key symptoms include hyperphagia, severe early-onset obesity, and hypogonadotropic hypogonadism (a condition in which the male testes or the female ovaries produce little or no sex hormones, due to a problem with the pituitary gland or hypothalamus).
- Bardet-Biedl Syndrome (BBS): Key symptoms include early-onset obesity, hyperphagia, vision impairment, polydactyly (having an extra finger or toe), and kidney impairment.
Complications Associated with Overweight and Obesity
According to the Centre for Disease Prevention and Control (CDC) (2020), people who have obesity, compared to those with a normal or healthy weight, are at increased risk for many serious diseases and health conditions, including the following as highlighted by National Health, Lung and Blood Institute (NHLBI)(2013); NHLBI (1998); Bhaskaran, Douglas, Forbes, dos-Santos-Silva, Leon and Smeeth (2014):
- All-causes of death (mortality)
- High blood pressure (Hypertension)
- High LDL cholesterol, low HDL cholesterol, or high levels of triglycerides (Dyslipidemia)
- Type 2 diabetes
- Coronary heart disease
- Gallbladder disease
- Osteoarthritis (a breakdown of cartilage and bone within a joint)
- Sleep apnea and breathing problems
- Many types of cancer
- Low quality of life
- Mental illness such as clinical depression, anxiety, and other mental disorders [(Kasen et al., 2008); Luppino et al., (2010)].
- Body pain and difficulty with physical functioning (Roberts et al., 2003).
Treatment for Overweight & Obesity
National Institute of Diabetes and Digestive and Kidney Disease (2018) highlighted common treatments for overweight and obesity to include the following:
- Healthy eating plan and regular physical activity
- Changing your habits
- Weight-management programs
- Weight-loss medicines
- Weight-loss devices
- Bariatric surgery
- Special diets
Healthy Eating Plan and Regular Physical Activity
Following a healthy eating plan with fewer calories is often the first step in trying to treat overweight and obesity. People who are overweight or have obesity should also start regular physical activity when they begin their healthy eating plan. Being active may help you use calories. Regular physical activity may help you stay at a healthy weight (National Institute of Diabetes and Digestive and Kidney Disease, 2018).
Changing Your Habits
Changing your eating and physical activity habits and lifestyle is difficult, but with a plan, effort, regular support, and patience, you may be able to lose weight and improve your health. The following tips may help you think about ways to lose weight, engage in regular physical activity, and improve health over the long-term.
- Be Prepared for Setbacks: After a setback, like overeating at a family or workplace gathering, try to regroup and focus on getting back to your healthy eating plan as soon as you can. Try to eat only when you’re sitting at your dining room or kitchen table. At work, avoid areas where treats may be available. Track your progress using online food or physical activity trackers, such as the Body Weight Planner, that can help you keep track of the foods you eat, your physical activity, and your weight. These tools may help you stick with it and stay motivated.
- Set Goals: Having specific goals can help you stay on track. Rather than “be more active,” set a goal to walk 15 to 30 minutes before work or at lunch on Monday and Friday. If you miss a walk on Monday, pick it up again Tuesday.
- Seek Support: Ask for help or encouragement from your family, friends, or health care professionals. You can get support in person, through email or texting, or by talking on the phone. You can also join a support group. Specially trained health professionals can help you change your lifestyle.
(National Institute of Diabetes and Digestive and Kidney Disease, 2018).
Weight Management Programs
Some people benefit from a formal weight-management program. In a weight-management program, trained weight-management specialists will design a broad plan just for you and help you carry out your plan. Plans include a lower-calorie diet, increased physical activity, and ways to help you change your habits and stick with them. You may work with the specialists on-site (that is, face-to-face) in individual or group sessions. The specialists may contact you regularly by telephone or internet to help support your plan. Devices such as smartphones, pedometers, and accelerometers may help you track how well you are sticking with your plan (National Institute of Diabetes and Digestive and Kidney Disease, 2018).
When healthy eating and physical activity habits are not enough, your doctor may prescribe medicines to treat overweight and obesity. You should try to stick with your healthy eating plan and continue getting regular physical activity while taking weight-loss medicines. You may see ads for herbal remedies and dietary supplements claiming to help you lose weight. But many of these claims are not true. Some of these supplements can even have serious side effects. Talk with your doctor before taking any over-the-counter herbal remedies or dietary supplements for the purpose of trying to lose weight (National Institute of Diabetes and Digestive and Kidney Disease, 2018).
Your doctor may consider weight-loss devices if you haven’t been able to lose weight or keep from gaining back any weight you lost with other treatments. Because weight-loss devices have only recently been approved, researchers do not have long-term data on their safety and effectiveness. Weight-loss devices include
- Electrical Stimulation System: The electrical stimulation system uses a device a surgeon places in your abdomen with laparoscopic surgery. The device blocks nerve activity between your stomach and brain.
- Gastric Balloon System: For the gastric balloon system, a doctor places one or two balloons in your stomach through a tube that goes in your mouth. Once the balloons are in your stomach, the surgeon fills them with salt water so they take up more space in your stomach and help you feel fuller.
- Gastric Emptying System: A gastric emptying system uses a pump to drain part of the food from your stomach after a meal. The device includes a tube that goes from the inside of your stomach to the outside of your abdomen. About 20 to 30 minutes after eating, you use the pump to drain the food from your stomach through the tube into the toilet.
(National Institute of Diabetes and Digestive and Kidney Disease, 2018).
Bariatric surgery includes several types of operations that help you lose weight by making changes to your digestive system. Bariatric surgery may be an option if you have extreme obesity and haven’t been able to lose enough weight to improve your health or keep from gaining back the weight you lost with other treatments. Bariatric surgery also may be an option at lower levels of obesity if you have serious health problems, such as type 2 diabetes or sleep apnea, related to obesity. Bariatric surgery can improve many of the medical conditions linked to obesity, especially type 2 diabetes (National Institute of Diabetes and Digestive and Kidney Disease, 2018).
The following are the recommended special diets by National Institute of Diabetes and Digestive and Kidney Disease (2018) for the treatment of overweight and obesity:
Calorie-restricted Diets: Your doctor may recommend a lower-calorie diet such as 1,200 to 1,500 calories a day for women and 1,500 to 1,800 calories a day for men. The calorie level depends on your body weight and physical activity level. A lower calorie diet with a variety of healthy foods will give you the nutrients you need to stay healthy.
Intermittent Fasting: Intermittent fasting is another way of reducing food intake that is gaining attention as a strategy for weight loss and health benefits. Alternate-day fasting is one type of intermittent fasting that consists of a “fast day” (eating no calories to one-fourth of caloric needs) alternating with a “fed day,” or a day of unrestricted eating. Researchers have conducted only a few studies of intermittent fasting as a strategy for weight loss. They have no long-term data on the safety and effectiveness of intermittent fasting for long-term weight maintenance.
Prevention of Overweight and Obesity
Mayo Clinic (2020) highlighted the following measures for to prevent overweight and obesity:
- Exercise Regularly: You need to get 150 to 300 minutes of moderate-intensity activity a week to prevent weight gain. Moderately intense physical activities include fast walking and swimming.
- Follow a Healthy-Eating Plan: Focus on low-calorie, nutrient-dense foods, such as fruits, vegetables and whole grains. Avoid saturated fat and limit sweets and alcohol. Eat three regular meals a day with limited snacking. You can still enjoy small amounts of high-fat, high-calorie foods as an infrequent treat. Just be sure to choose foods that promote a healthy weight and good health most of the time.
- Know and Avoid the Food Traps that Cause You to Eat: Identify situations that trigger out-of-control eating. Try keeping a journal and write down what you eat, how much you eat, when you eat, how you’re feeling and how hungry you are. After a while, you should see patterns emerge. You can plan ahead and develop strategies for handling these types of situations and stay in control of your eating behaviors.
- Monitor your Weight Regularly: People who weigh themselves at least once a week are more successful in keeping off excess pounds. Monitoring your weight can tell you whether your efforts are working and can help you detect small weight gains before they become big problems.
- Be Consistent: Sticking to your healthy-weight plan during the week, on the weekends, and amidst vacation and holidays as much as possible increases your chances of long-term success.
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